这篇文章主要围绕一般JAVA高级工程师的知识深度？和一般java高级工程师的知识深度是多少展开，旨在为您提供一份详细的参考资料。我们将全面介绍一般JAVA高级工程师的知识深度？的优缺点，解答一般jav
这篇文章主要围绕一般 JAVA 高级工程师的知识深度？和一般 java 高级工程师的知识深度是多少展开，旨在为您提供一份详细的参考资料。我们将全面介绍一般 JAVA 高级工程师的知识深度？的优缺点，解答一般 java 高级工程师的知识深度是多少的相关问题，同时也会为您带来4-1 如何定义 Java 中的方法；Java 中无参无返回值方法的使用；Java 中无参带返回值方法的使用；、5-2 Java 中的 static 使用之静态变量 ;;Java 中的 static 使用之静态方法;;Java 中的 static 使用之静态初始化块、ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]、Elasticsearch Java client（ES Client 简介、Java REST Client、Java Client、Spring Data Elasticsearch）的实用方法。
本文目录一览：- 一般 JAVA 高级工程师的知识深度？（一般 java 高级工程师的知识深度是多少）
- 4-1 如何定义 Java 中的方法；Java 中无参无返回值方法的使用；Java 中无参带返回值方法的使用；
- 5-2 Java 中的 static 使用之静态变量 ;;Java 中的 static 使用之静态方法;;Java 中的 static 使用之静态初始化块
- ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
- Elasticsearch Java client（ES Client 简介、Java REST Client、Java Client、Spring Data Elasticsearch）
一般 JAVA 高级工程师的知识深度？（一般 java 高级工程师的知识深度是多少）
一个 Java 高级工程师，对 jdk 重点源码深刻理解，达到如下程度？。
例如为什么 Thread 里有一个 ThreadLocalMap 类型的变量
ThreadLocalMap 为什么作为 ThreadLocal 的内部类
ThreadLocalMap 的扩缩容机制以及碰撞检测
ThreadLocalMap 的 Entry 为什么使用弱引用类型
有些类中的 capacity,threshold,position,mark,limit 这些成员变量有什么用，如何影响类内部的运算？如何设置？
同理对其他重点类也要掌握至此，甚至达到凭记忆默写部分源码或关键源码的程度。
重点 IO、线程、集合，锁、字符串（String,StringBuffer,StringBuilder）。。。。
JVM 了解 GC 算法大类，每个大类里具体有哪些算法，
并可以叙述算法步骤，并了解每一步的理由。
熟练讲述常见 JVM 的内存结构，历代结构变迁及其改进理由。
各类 JVM 中 GC 垃圾收集器的种类以及使用场景（优缺点），各类收集器分别使用了什么 GC 算法来达到它们所描述的性能及功能要求，并且是如何达到的。
可以依据具体的应用场景，选择合适的 JVM 及参数，尽可能挖掘应用程序和宿主机潜力。
拥有手动改写字节码的能力（这里含义就是了解字节码结构及含义）
了解部分重点 native 方法的实现逻辑（不需要了解语法）
熟练说出各个 JDK 版本变迁的主要核心内容
对于重要的 JSR 可以快速说出 JSR 编号
熟练应用 JAVA EE 技术进行开发，可以快速上手各类 Java 开发框架这种自然是必备条件。
以上，仅限于 JAVA 技术平台，是暂时想到的，你们觉得过了还是不够？
4-1 如何定义 Java 中的方法；Java 中无参无返回值方法的使用；Java 中无参带返回值方法的使用；
1.一般情况下，定义一个方法的语法是：
访问修饰符 返回值类型 方法名（参数列表）{
方法体
}1、 访问修饰符：方法允许被访问的权限范围， 可以是 public、protected、private 甚至可以省略 ，其中 public 表示该方法可以被其他任何代码调用，其他几种修饰符的使用在后面章节中会详细讲解滴
2、 返回值类型：方法返回值的类型，如果方法不返回任何值，则返回值类型指定为 void ；如果方法具有返回值，则需要指定返回值的类型，并且在方法体中使用 return 语句返回值
3、 方法名：定义的方法的名字，必须使用合法的标识符
4、 参数列表：传递给方法的参数列表，参数可以有多个，多个参数间以逗号隔开，每个参数由参数类型和参数名组成，以空格隔开
根据方法是否带参、是否带返回值，可将方法分为四类：
Ø 无参无返回值方法
Ø 无参带返回值方法
Ø 带参无返回值方法
Ø 带参带返回值方法
public class HelloWorld {
//定义了一个方法名为 print 的方法，实现输出信息功能
public void print() {
System.out.println("Hello World");
}
public static void main(String[] args){
//在 main 方法中调用 print 方法
HelloWorld test=new HelloWorld();
test.print();
}
}
2.Java 中无参无返回值方法的使用（如果方法不包含参数，且没有返回值，称为无参无返回值的方法。）
方法的使用分两步
例如：下面代码定义了一个方法名为 show ，没有参数，且没有返回值的方法，执行的操作为输出 “ welcome to imooc. ”
注意：
1、 方法体放在一对大括号中，实现特定的操作
2、 方法名主要在调用这个方法时使用，需要注意命名的规范，一般采用第一个单词首字母小写，其它单词首字母大写的形式
第二步，调用方法
当需要调用方法执行某个操作时，可以先创建类的对象，然后通过 对象名.方法名(); 来实现（关于类和对象的概念在后面章节中会详细讲解滴，先熟悉语法，表着急哦~~）
例如：在下面的代码中，我们创建了一个名为 hello 的对象，然后通过调用该对象的 show( ) 方法输出信息
运行结果为： welcome to imooc.
3.Java 中无参带返回值方法的使用
如果方法不包含参数，但有返回值，我们称为无参带返回值的方法。
例如：下面的代码，定义了一个方法名为 calSum ，无参数，但返回值为 int 类型的方法，执行的操作为计算两数之和，并返回结果
在 calSum( ) 方法中，返回值类型为 int 类型，因此在方法体中必须使用 return 返回一个整数值。
运行结果为： 两数之和为：17
不容忽视的“小陷阱”：
1、 如果方法的返回类型为 void ，则方法中不能使用 return 返回值！
2、 方法的返回值最多只能有一个，不能返回多个值
3、 方法返回值的类型必须兼容，例如，如果返回值类型为 int ，则不能返回 String 型值
5-2 Java 中的 static 使用之静态变量 ;;Java 中的 static 使用之静态方法;;Java 中的 static 使用之静态初始化块
1.Java 中被 static 修饰的成员称为静态成员或类成员。它属于整个类所有，而不是某个对象所有，即被类的所有对象所共享。静态成员可以使用类名直接访问，也可以使用对象名进行访问。当然，鉴于他作用的特殊性更推荐用类名访问
使用 static 可以修饰变量、方法和代码块。
2. 与静态变量一样，我们也可以使用 static 修饰方法，称为静态方法或类方法。其实之前我们一直写的 main 方法就是静态方法。静态方法的使用如：
注意：
1、 静态方法中可以直接调用同类中的静态成员，但不能直接调用非静态成员。如：
如果希望在静态方法中调用非静态变量，可以通过创建类的对象，然后通过对象来访问非静态变量。如：
2、 在普通成员方法中，则可以直接访问同类的非静态变量和静态变量，如下所示：
3、 静态方法中不能直接调用非静态方法，需要通过对象来访问非静态方法。如：
3.Java 中的 static 使用之静态初始化块
Java 中可以通过初始化块进行数据赋值。如：
在类的声明中，可以包含多个初始化块，当创建类的实例时，就会依次执行这些代码块。如果使用 static 修饰初始化块，就称为静态初始化块。
注意：静态初始化块只在类加载时执行，且只会执行一次，同时静态初始化块只能给静态变量赋值，不能初始化普通的成员变量。
![ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]](http://www.gvkun.com/zb_users/upload/2025/05/aac3db62-e1f9-46d6-95cc-522153c38e261746040016594.jpg "ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]")
ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
错误堆栈：
java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
at android.support.v4.util.SimpleArrayMap.allocArrays(SourceFile:183)
at android.support.v4.util.SimpleArrayMap.put(SourceFile:437)
错误原因：
由于SimpleArrayMap 里面使用了一个静态变量的缓存，mBaseCache,
static Object[] mBaseCache;
该变量默认有两个数据，第1个元素是一个object[]，用于存放上次的缓存的mBaseCache
第二个元素是int[]，用于存在hash。具体赋值代码可以看下面
synchronized (ArrayMap.class) {
if (mBaseCacheSize < CACHE_SIZE) {
array[0] = mBaseCache;
array[1] = hashes;
for (int i=(size<<1)-1; i>=2; i--) {
array[i] = null;
}
mBaseCache = array;
mBaseCacheSize++;
if (DEBUG) Log.d(TAG, "Storing 1x cache " + array
+ " now have " + mBaseCacheSize + " entries");
}
}
使用该数组的地方在：
SimpleArrayMap 的allocArrays 方法里
synchronized (ArrayMap.class) {
if (mBaseCache != null) {
final Object[] array = mBaseCache;
mArray = array;
mBaseCache = (Object[])array[0];
mHashes = (int[])array[1];
array[0] = array[1] = null;
mBaseCacheSize--;
if (DEBUG) Log.d(TAG, "Retrieving 1x cache " + mHashes
+ " now have " + mBaseCacheSize + " entries");
return;
}
}
下面这段代码是有风险的，如果mBaseCache 在多线程被修改了，就会把ClassCastException 异常。
mBaseCache = (Object[])array[0];
解决方法：
如果项目某个地方报这个错误，请把这个地方的ArrayMap替换成 HasMap. HasMap 多线程不会崩溃，虽然，他不是特别完好的支持。不需要把项目中所有的地方都替换掉，没有必要。单独线程，ArrayMap 完全没有问题。
错误复现：这个复现起来超级麻烦，我花了一周的时间，才找到复现的漏洞，分享给大家：
/**
* 复现该问题 用了四个线程
* java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]
* at android.support.v4.util.SimpleArrayMap.allocArrays(SimpleArrayMap.java:157)
* at android.support.v4.util.SimpleArrayMap.put(SimpleArrayMap.java:399)
* at com.example.fragment.MainFragment$14.run(MainFragment.java:280)
* 1.首先 线程1 执行到put 方法的
* mArray[index<<1] = key;
* mArray[(index<<1)+1] = value;
* mSize++;
* return null;
* 最上面这个位置 目的是让这个数组不再是空的
*
* 2.执行线程2 也执行到
* mArray[index<<1] = key;
* mArray[(index<<1)+1] = value;
* mSize++;
* return null;
* 最上面这个位置 目的是让这个put 的东西，放在第0个位置，因为put里面会生成index，
* 让两个线程都放到index 是0 的位置
*
* 3.把线程1执行完，这样数据里面已经放进去一个数据了
*
* 4.执行线程3 到removeAt 方法的 freeArrays 的 mBaseCache = array; 之前
* public V removeAt(int index) {
* final Object old = mArray[(index << 1) + 1];
* if (mSize <= 1) {
* // Now empty.
* if (DEBUG) Log.d(TAG, "remove: shrink from " + mHashes.length + " to 0");
* freeArrays(mHashes, mArray, mSize);
*
* mBaseCache = array;----------- freeArrays
*
* 这个的目的是调用freeArray 方法，让当前的map释放当前的数组。这样就可以生成mBaseCache了
*
* 5.把线程2 执行完
* 这样就会把mBaseCache 赋值的数组，重新赋值
*
* 6.把线程3执行完
* ok，现在mBaseCache已经被污染了
*
* 7.执行线程4
*
*/
private void CMETestCastException() {
final ArrayMap testArrayMap = new ArrayMap();
final ArrayMap testArrayMap2 = new ArrayMap();
new Thread("线程1"){
@Override
public void run() {
super.run();
testArrayMap.put("2324","fffff");
}
}.start();
new Thread("线程2"){
@Override
public void run() {
super.run();
testArrayMap.put("test","string");
}
}.start();
new Thread("线程3"){
@Override
public void run() {
super.run();
testArrayMap.removeAt(0);
}
}.start();
new Thread("线程4"){
@Override
public void run() {
super.run();
testArrayMap2.put("aaa","string");
}
}.start();
}
复现这个问题的时候，关键是把mBaseCache 污染掉。这里四个线程的话，需要调试，调试步骤就是上面我注释的。
总结：
如果当前的map 会有多个线程访问，请使用HasMap. 该问题，google 并没有解决。在高版本上，直接扔CME ConcurrentModificationException.
Elasticsearch Java client（ES Client 简介、Java REST Client、Java Client、Spring Data Elasticsearch）
elasticsearch系列七：ES Java客户端-Elasticsearch Java client（ES Client 简介、Java REST Client、Java Client、Spring Data Elasticsearch）
一、ES Client 简介
1. ES是一个服务，采用C/S结构
2. 回顾 ES的架构
3. ES支持的客户端连接方式
3.1 REST API ，端口 9200
这种连接方式对应于架构图中的RESTful style API这一层，这种客户端的连接方式是RESTful风格的，使用http的方式进行连接
3.2 Transport 连接 端口 9300
这种连接方式对应于架构图中的Transport这一层，这种客户端连接方式是直接连接ES的节点，使用TCP的方式进行连接
4. ES提供了多种编程语言客户端
官网可以了解详情：
https://www.elastic.co/guide/en/elasticsearch/client/index.html
二、Java REST Client介绍
1. ES提供了两个JAVA REST client 版本
Java Low Level REST Client: 低级别的REST客户端，通过http与集群交互，用户需自己编组请求JSON串，及解析响应JSON串。兼容所有ES版本。
Java High Level REST Client: 高级别的REST客户端，基于低级别的REST客户端，增加了编组请求JSON串、解析响应JSON串等相关api。使用的版本需要保持和ES服务端的版本一致，否则会有版本问题。
2. Java Low Level REST Client 说明
特点，maven 引入、使用介绍： https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-low.html
API doc ：https://artifacts.elastic.co/javadoc/org/elasticsearch/client/elasticsearch-rest-client/6.2.4/index.html.
3. Java High Level REST Client 说明
从6.0.0开始加入的，目的是以java面向对象的方式来进行请求、响应处理。
每个API 支持 同步/异步 两种方式，同步方法直接返回一个结果对象。异步的方法以async为后缀，通过listener参数来通知结果。
高级java REST 客户端依赖Elasticsearch core project
兼容性说明：
依赖 java1.8 和 Elasticsearch core project
请使用与服务端ES版本一致的客户端版本
4. Java High Level REST Client maven 集成
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.2.4</version>
</dependency>5. Java High Level REST Client 初始化
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(
new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http")));给定集群的多个节点地址，将客户端负载均衡地向这个节点地址集发请求
Client 不再使用了，记得关闭它：
client.close();API及用法示例，请参考：
https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-supported-apis.html
三、Java High Level REST Client 使用示例
准备：
编写示例之前首先在maven工程里面引入和ES服务端版本一样的Java客户端
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>elasticsearch-rest-high-level-client</artifactId>
<version>6.2.4</version>
</dependency>给定集群的多个节点地址，将客户端负载均衡地向这个节点地址集发请求：
InitDemo.java
package com.study.es_hrset_client;
import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
/**
*
* @Description: 获取Java High Level REST Client客户端
* @author lgs
* @date 2018年6月23日
*
*/
public class InitDemo {
public static RestHighLevelClient getClient() {
RestHighLevelClient client = new RestHighLevelClient(
RestClient.builder(new HttpHost("localhost", 9200, "http"),
new HttpHost("localhost", 9201, "http")));
return client;
}
}注意使用ES的客户端时类比之前我们在Kibana进行的ES的相关操作，这样使用起来更加有效果
1. Create index 创建索引
CreateIndexDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import org.elasticsearch.action.admin.indices.alias.Alias;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentType;
/**
*
* @Description: 创建索引
* @author lgs
* @date 2018年6月23日
*
*/
public class CreateIndexDemo {
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建 创建索引request 参数：索引名mess
CreateIndexRequest request = new CreateIndexRequest("mess");
// 2、设置索引的settings
request.settings(Settings.builder().put("index.number_of_shards", 3) // 分片数
.put("index.number_of_replicas", 2) // 副本数
.put("analysis.analyzer.default.tokenizer", "ik_smart") // 默认分词器
);
// 3、设置索引的mappings
request.mapping("_doc",
" {\n" +
" \"_doc\": {\n" +
" \"properties\": {\n" +
" \"message\": {\n" +
" \"type\": \"text\"\n" +
" }\n" +
" }\n" +
" }\n" +
" }",
XContentType.JSON);
// 4、 设置索引的别名
request.alias(new Alias("mmm"));
// 5、 发送请求
// 5.1 同步方式发送请求
CreateIndexResponse createIndexResponse = client.indices()
.create(request);
// 6、处理响应
boolean acknowledged = createIndexResponse.isAcknowledged();
boolean shardsAcknowledged = createIndexResponse
.isShardsAcknowledged();
System.out.println("acknowledged = " + acknowledged);
System.out.println("shardsAcknowledged = " + shardsAcknowledged);
// 5.1 异步方式发送请求
/*ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
@Override
public void onResponse(
CreateIndexResponse createIndexResponse) {
// 6、处理响应
boolean acknowledged = createIndexResponse.isAcknowledged();
boolean shardsAcknowledged = createIndexResponse
.isShardsAcknowledged();
System.out.println("acknowledged = " + acknowledged);
System.out.println(
"shardsAcknowledged = " + shardsAcknowledged);
}
@Override
public void onFailure(Exception e) {
System.out.println("创建索引异常：" + e.getMessage());
}
};
client.indices().createAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}运行结果：
acknowledged = true
shardsAcknowledged = true
2. index document
索引文档，即往索引里面放入文档数据.类似于数据库里面向表里面插入一行数据，一行数据就是一个文档
IndexDocumentDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.rest.RestStatus;
/**
*
* @Description: 索引文档，即往索引里面放入文档数据.类似于数据库里面向表里面插入一行数据，一行数据就是一个文档
* @author lgs
* @date 2018年6月23日
*
*/
public class IndexDocumentDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建索引请求
IndexRequest request = new IndexRequest(
"mess", //索引
"_doc", // mapping type
"1"); //文档id
// 2、准备文档数据
// 方式一：直接给JSON串
String jsonString = "{" +
"\"user\":\"kimchy\"," +
"\"postDate\":\"2013-01-30\"," +
"\"message\":\"trying out Elasticsearch\"" +
"}";
request.source(jsonString, XContentType.JSON);
// 方式二：以map对象来表示文档
/*
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "kimchy");
jsonMap.put("postDate", new Date());
jsonMap.put("message", "trying out Elasticsearch");
request.source(jsonMap);
*/
// 方式三：用XContentBuilder来构建文档
/*
XContentBuilder builder = XContentFactory.jsonBuilder();
builder.startObject();
{
builder.field("user", "kimchy");
builder.field("postDate", new Date());
builder.field("message", "trying out Elasticsearch");
}
builder.endObject();
request.source(builder);
*/
// 方式四：直接用key-value对给出
/*
request.source("user", "kimchy",
"postDate", new Date(),
"message", "trying out Elasticsearch");
*/
//3、其他的一些可选设置
/*
request.routing("routing"); //设置routing值
request.timeout(TimeValue.timeValueSeconds(1)); //设置主分片等待时长
request.setRefreshPolicy("wait_for"); //设置重刷新策略
request.version(2); //设置版本号
request.opType(DocWriteRequest.OpType.CREATE); //操作类别
*/
//4、发送请求
IndexResponse indexResponse = null;
try {
// 同步方式
indexResponse = client.index(request);
} catch(ElasticsearchException e) {
// 捕获，并处理异常
//判断是否版本冲突、create但文档已存在冲突
if (e.status() == RestStatus.CONFLICT) {
logger.error("冲突了，请在此写冲突处理逻辑！\n" + e.getDetailedMessage());
}
logger.error("索引异常", e);
}
//5、处理响应
if(indexResponse != null) {
String index = indexResponse.getIndex();
String type = indexResponse.getType();
String id = indexResponse.getId();
long version = indexResponse.getVersion();
if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
System.out.println("新增文档成功，处理逻辑代码写到这里。");
} else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
System.out.println("修改文档成功，处理逻辑代码写到这里。");
}
// 分片处理信息
ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
}
// 如果有分片副本失败，可以获得失败原因信息
if (shardInfo.getFailed() > 0) {
for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
String reason = failure.reason();
System.out.println("副本失败原因：" + reason);
}
}
}
//异步方式发送索引请求
/*ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
@Override
public void onResponse(IndexResponse indexResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.indexAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}运行结果：
新增文档成功，处理逻辑代码写到这里。
3. get document
获取文档数据
GetDocumentDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import java.util.Map;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.Strings;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
/**
*
* @Description: 获取文档数据
* @author lgs
* @date 2018年6月23日
*
*/
public class GetDocumentDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建获取文档请求
GetRequest request = new GetRequest(
"mess", //索引
"_doc", // mapping type
"1"); //文档id
// 2、可选的设置
//request.routing("routing");
//request.version(2);
//request.fetchSourceContext(new FetchSourceContext(false)); //是否获取_source字段
//选择返回的字段
String[] includes = new String[]{"message", "*Date"};
String[] excludes = Strings.EMPTY_ARRAY;
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);
//也可写成这样
/*String[] includes = Strings.EMPTY_ARRAY;
String[] excludes = new String[]{"message"};
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);*/
// 取stored字段
/*request.storedFields("message");
GetResponse getResponse = client.get(request);
String message = getResponse.getField("message").getValue();*/
//3、发送请求
GetResponse getResponse = null;
try {
// 同步请求
getResponse = client.get(request);
} catch (ElasticsearchException e) {
if (e.status() == RestStatus.NOT_FOUND) {
logger.error("没有找到该id的文档" );
}
if (e.status() == RestStatus.CONFLICT) {
logger.error("获取时版本冲突了，请在此写冲突处理逻辑！" );
}
logger.error("获取文档异常", e);
}
//4、处理响应
if(getResponse != null) {
String index = getResponse.getIndex();
String type = getResponse.getType();
String id = getResponse.getId();
if (getResponse.isExists()) { // 文档存在
long version = getResponse.getVersion();
String sourceAsString = getResponse.getSourceAsString(); //结果取成 String
Map<String, Object> sourceAsMap = getResponse.getSourceAsMap(); // 结果取成Map
byte[] sourceAsBytes = getResponse.getSourceAsBytes(); //结果取成字节数组
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info(sourceAsString);
} else {
logger.error("没有找到该id的文档" );
}
}
//异步方式发送获取文档请求
/*
ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
@Override
public void onResponse(GetResponse getResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.getAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}4. Bulk
批量索引文档，即批量往索引里面放入文档数据.类似于数据库里面批量向表里面插入多行数据，一行数据就是一个文档
BulkDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.DocWriteRequest;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.xcontent.XContentType;
/**
*
* @Description: 批量索引文档，即批量往索引里面放入文档数据.类似于数据库里面批量向表里面插入多行数据，一行数据就是一个文档
* @author lgs
* @date 2018年6月23日
*
*/
public class BulkDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建批量操作请求
BulkRequest request = new BulkRequest();
request.add(new IndexRequest("mess", "_doc", "1")
.source(XContentType.JSON,"field", "foo"));
request.add(new IndexRequest("mess", "_doc", "2")
.source(XContentType.JSON,"field", "bar"));
request.add(new IndexRequest("mess", "_doc", "3")
.source(XContentType.JSON,"field", "baz"));
/*
request.add(new DeleteRequest("mess", "_doc", "3"));
request.add(new UpdateRequest("mess", "_doc", "2")
.doc(XContentType.JSON,"other", "test"));
request.add(new IndexRequest("mess", "_doc", "4")
.source(XContentType.JSON,"field", "baz"));
*/
// 2、可选的设置
/*
request.timeout("2m");
request.setRefreshPolicy("wait_for");
request.waitForActiveShards(2);
*/
//3、发送请求
// 同步请求
BulkResponse bulkResponse = client.bulk(request);
//4、处理响应
if(bulkResponse != null) {
for (BulkItemResponse bulkItemResponse : bulkResponse) {
DocWriteResponse itemResponse = bulkItemResponse.getResponse();
if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.INDEX
|| bulkItemResponse.getOpType() == DocWriteRequest.OpType.CREATE) {
IndexResponse indexResponse = (IndexResponse) itemResponse;
//TODO 新增成功的处理
} else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.UPDATE) {
UpdateResponse updateResponse = (UpdateResponse) itemResponse;
//TODO 修改成功的处理
} else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.DELETE) {
DeleteResponse deleteResponse = (DeleteResponse) itemResponse;
//TODO 删除成功的处理
}
}
}
//异步方式发送批量操作请求
/*
ActionListener<BulkResponse> listener = new ActionListener<BulkResponse>() {
@Override
public void onResponse(BulkResponse bulkResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.bulkAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}5. search
搜索数据
SearchDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.ShardSearchFailure;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.term.TermSuggestion;
/**
*
* @Description: 搜索数据
* @author lgs
* @date 2018年6月23日
*
*/
public class SearchDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("bank");
searchRequest.types("_doc");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构造QueryBuilder
/*QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("user", "kimchy")
.fuzziness(Fuzziness.AUTO)
.prefixLength(3)
.maxExpansions(10);
sourceBuilder.query(matchQueryBuilder);*/
sourceBuilder.query(QueryBuilders.termQuery("age", 24));
sourceBuilder.from(0);
sourceBuilder.size(10);
sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
//是否返回_source字段
//sourceBuilder.fetchSource(false);
//设置返回哪些字段
/*String[] includeFields = new String[] {"title", "user", "innerObject.*"};
String[] excludeFields = new String[] {"_type"};
sourceBuilder.fetchSource(includeFields, excludeFields);*/
//指定排序
//sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC));
//sourceBuilder.sort(new FieldSortBuilder("_uid").order(SortOrder.ASC));
// 设置返回 profile
//sourceBuilder.profile(true);
//将请求体加入到请求中
searchRequest.source(sourceBuilder);
// 可选的设置
//searchRequest.routing("routing");
// 高亮设置
/*
HighlightBuilder highlightBuilder = new HighlightBuilder();
HighlightBuilder.Field highlightTitle =
new HighlightBuilder.Field("title");
highlightTitle.highlighterType("unified");
highlightBuilder.field(highlightTitle);
HighlightBuilder.Field highlightUser = new HighlightBuilder.Field("user");
highlightBuilder.field(highlightUser);
sourceBuilder.highlighter(highlightBuilder);*/
//加入聚合
/*TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
.field("company.keyword");
aggregation.subAggregation(AggregationBuilders.avg("average_age")
.field("age"));
sourceBuilder.aggregation(aggregation);*/
//做查询建议
/*SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.termSuggestion("user").text("kmichy");
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);*/
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
RestStatus status = searchResponse.status();
TimeValue took = searchResponse.getTook();
Boolean terminatedEarly = searchResponse.isTerminatedEarly();
boolean timedOut = searchResponse.isTimedOut();
//分片搜索情况
int totalShards = searchResponse.getTotalShards();
int successfulShards = searchResponse.getSuccessfulShards();
int failedShards = searchResponse.getFailedShards();
for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
// failures should be handled here
}
//处理搜索命中文档结果
SearchHits hits = searchResponse.getHits();
long totalHits = hits.getTotalHits();
float maxScore = hits.getMaxScore();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
// do something with the SearchHit
String index = hit.getIndex();
String type = hit.getType();
String id = hit.getId();
float score = hit.getScore();
//取_source字段值
String sourceAsString = hit.getSourceAsString(); //取成json串
Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
//从map中取字段值
/*
String documentTitle = (String) sourceAsMap.get("title");
List<Object> users = (List<Object>) sourceAsMap.get("user");
Map<String, Object> innerObject = (Map<String, Object>) sourceAsMap.get("innerObject");
*/
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info(sourceAsString);
//取高亮结果
/*Map<String, HighlightField> highlightFields = hit.getHighlightFields();
HighlightField highlight = highlightFields.get("title");
Text[] fragments = highlight.fragments();
String fragmentString = fragments[0].string();*/
}
// 获取聚合结果
/*
Aggregations aggregations = searchResponse.getAggregations();
Terms byCompanyAggregation = aggregations.get("by_company");
Bucket elasticBucket = byCompanyAggregation.getBucketByKey("Elastic");
Avg averageAge = elasticBucket.getAggregations().get("average_age");
double avg = averageAge.getValue();
*/
// 获取建议结果
/*Suggest suggest = searchResponse.getSuggest();
TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user");
for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
for (TermSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
}
}
*/
//异步方式发送获查询请求
/*
ActionListener<SearchResponse> listener = new ActionListener<SearchResponse>() {
@Override
public void onResponse(SearchResponse getResponse) {
//结果获取
}
@Override
public void onFailure(Exception e) {
//失败处理
}
};
client.searchAsync(searchRequest, listener);
*/
} catch (IOException e) {
logger.error(e);
}
}
}6. highlight 高亮
HighlightDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import java.util.Map;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
/**
*
* @Description: 高亮
* @author lgs
* @date 2018年6月23日
*
*/
public class HighlightDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
SearchRequest searchRequest = new SearchRequest("hl_test");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构造QueryBuilder
QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "lucene solr");
sourceBuilder.query(matchQueryBuilder);
//分页设置
/*sourceBuilder.from(0);
sourceBuilder.size(5); ;*/
// 高亮设置
HighlightBuilder highlightBuilder = new HighlightBuilder();
highlightBuilder.requireFieldMatch(false).field("title").field("content")
.preTags("<strong>").postTags("</strong>");
//不同字段可有不同设置，如不同标签
/*HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title");
highlightTitle.preTags("<strong>").postTags("</strong>");
highlightBuilder.field(highlightTitle);
HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
highlightContent.preTags("<b>").postTags("</b>");
highlightBuilder.field(highlightContent).requireFieldMatch(false);*/
sourceBuilder.highlighter(highlightBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
if(RestStatus.OK.equals(searchResponse.status())) {
//处理搜索命中文档结果
SearchHits hits = searchResponse.getHits();
long totalHits = hits.getTotalHits();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
String index = hit.getIndex();
String type = hit.getType();
String id = hit.getId();
float score = hit.getScore();
//取_source字段值
//String sourceAsString = hit.getSourceAsString(); //取成json串
Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
//从map中取字段值
/*String title = (String) sourceAsMap.get("title");
String content = (String) sourceAsMap.get("content"); */
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info("sourceMap : " + sourceAsMap);
//取高亮结果
Map<String, HighlightField> highlightFields = hit.getHighlightFields();
HighlightField highlight = highlightFields.get("title");
if(highlight != null) {
Text[] fragments = highlight.fragments(); //多值的字段会有多个值
if(fragments != null) {
String fragmentString = fragments[0].string();
logger.info("title highlight : " + fragmentString);
//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
//sourceAsMap.put("title", fragmentString);
}
}
highlight = highlightFields.get("content");
if(highlight != null) {
Text[] fragments = highlight.fragments(); //多值的字段会有多个值
if(fragments != null) {
String fragmentString = fragments[0].string();
logger.info("content highlight : " + fragmentString);
//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
//sourceAsMap.put("content", fragmentString);
}
}
}
}
} catch (IOException e) {
logger.error(e);
}
}
}7. suggest 查询建议
SuggestDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.SuggestionBuilder;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.elasticsearch.search.suggest.term.TermSuggestion;
/**
*
* @Description: 查询建议
* @author lgs
* @date 2018年6月23日
*
*/
public class SuggestDemo {
private static Logger logger = LogManager.getRootLogger();
//词项建议拼写检查，检查用户的拼写是否错误，如果有错给用户推荐正确的词，appel->apple
public static void termSuggest() {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("mess");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//做查询建议
//词项建议
SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.termSuggestion("user").text("kmichy");
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取建议结果
Suggest suggest = searchResponse.getSuggest();
TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user");
for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
logger.info("text: " + entry.getText().string());
for (TermSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
logger.info(" suggest option : " + suggestText);
}
}
}
/*
"suggest": {
"my-suggestion": [
{
"text": "tring",
"offset": 0,
"length": 5,
"options": [
{
"text": "trying",
"score": 0.8,
"freq": 1
}
]
},
{
"text": "out",
"offset": 6,
"length": 3,
"options": []
},
{
"text": "elasticsearch",
"offset": 10,
"length": 13,
"options": []
}
]
}*/
} catch (IOException e) {
logger.error(e);
}
}
//自动补全，根据用户的输入联想到可能的词或者短语
public static void completionSuggester() {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("music");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//做查询建议
//自动补全
/*POST music/_search?pretty
{
"suggest": {
"song-suggest" : {
"prefix" : "lucene s",
"completion" : {
"field" : "suggest" ,
"skip_duplicates": true
}
}
}
}*/
SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.completionSuggestion("suggest").prefix("lucene s")
.skipDuplicates(true);
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("song-suggest", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取建议结果
Suggest suggest = searchResponse.getSuggest();
CompletionSuggestion termSuggestion = suggest.getSuggestion("song-suggest");
for (CompletionSuggestion.Entry entry : termSuggestion.getEntries()) {
logger.info("text: " + entry.getText().string());
for (CompletionSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
logger.info(" suggest option : " + suggestText);
}
}
}
} catch (IOException e) {
logger.error(e);
}
}
public static void main(String[] args) {
termSuggest();
logger.info("--------------------------------------");
completionSuggester();
}
}8. aggregation 聚合分析
AggregationDemo.java
package com.study.es_hrset_client;
import java.io.IOException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.BucketOrder;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.aggregations.metrics.avg.Avg;
import org.elasticsearch.search.builder.SearchSourceBuilder;
/**
*
* @Description: 聚合分析
* @author lgs
* @date 2018年6月23日
*
*/
public class AggregationDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (RestHighLevelClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("bank");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//加入聚合
//字段值项分组聚合
TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_age")
.field("age").order(BucketOrder.aggregation("average_balance", true));
//计算每组的平均balance指标
aggregation.subAggregation(AggregationBuilders.avg("average_balance")
.field("balance"));
sourceBuilder.aggregation(aggregation);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest);
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取聚合结果
Aggregations aggregations = searchResponse.getAggregations();
Terms byAgeAggregation = aggregations.get("by_age");
logger.info("aggregation by_age 结果");
logger.info("docCountError: " + byAgeAggregation.getDocCountError());
logger.info("sumOfOtherDocCounts: " + byAgeAggregation.getSumOfOtherDocCounts());
logger.info("------------------------------------");
for(Bucket buck : byAgeAggregation.getBuckets()) {
logger.info("key: " + buck.getKeyAsNumber());
logger.info("docCount: " + buck.getDocCount());
logger.info("docCountError: " + buck.getDocCountError());
//取子聚合
Avg averageBalance = buck.getAggregations().get("average_balance");
logger.info("average_balance: " + averageBalance.getValue());
logger.info("------------------------------------");
}
//直接用key 来去分组
/*Bucket elasticBucket = byCompanyAggregation.getBucketByKey("24");
Avg averageAge = elasticBucket.getAggregations().get("average_age");
double avg = averageAge.getValue();*/
}
} catch (IOException e) {
logger.error(e);
}
}
}9. 官网资料
各种查询对应的QueryBuilder：
https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-query-builders.html
各种聚合对应的AggregationBuilder：
https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-aggregation-builders.html
四、Java Client
1. Java Client 说明
java client 使用 TransportClient，各种操作本质上都是异步的(可以用 listener，或返回 Future ）。
注意：ES的发展规划中在7.0版本开始将废弃 TransportClient，8.0版本中将完全移除 TransportClient，取而代之的是High Level REST Client。
High Level REST Client 中的操作API和java client 大多是一样的。
2. 官方学习链接
https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/index.html
3. 兼容性说明
请使用与服务端ES版本一致的客户端版本
4. Java Client maven 集成
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>6.2.4</version>
</dependency>5. Java Client logger 日志器说明
使用的是 log4j2 日志组件。
如果要使用其他的日志组件，可使用slf4j作桥
6. Init Client
Init Client setting 可用参数说明：
cluster.name
指定集群的名字，如果集群的名字不是默认的elasticsearch，需指定。
client.transport.sniff
设置为true,将自动嗅探整个集群，自动加入集群的节点到连接列表中。
client.transport.ignore_cluster_name
Set to true to ignore cluster name validation of connected nodes. (since 0.19.4)
client.transport.ping_timeout
The time to wait for a ping response from a node. Defaults to 5s.
client.transport.nodes_sampler_interval
How often to sample / ping the nodes listed and connected. Defaults to 5s.
五、Java Client使用示例
注意：TransPort客户端的使用和RESTful风格的使用基本一致，除了获取客户端不一样，还有发送请求有的不一样外
准备：
编写示例之前首先在maven工程里面引入和ES服务端版本一样的Java客户端
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
<version>6.2.4</version>
</dependency>给定集群的多个节点地址，将客户端负载均衡地向这个节点地址集发请求：
InitDemo.java
package com.study.es_java_client;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.transport.client.PreBuiltTransportClient;
public class InitDemo {
private static TransportClient client;
public static TransportClient getClient() throws UnknownHostException {
if(client == null) {
//client = new PreBuiltTransportClient(Settings.EMPTY)
// 连接集群的设置
Settings settings = Settings.builder()
//.put("cluster.name", "myClusterName") //如果集群的名字不是默认的elasticsearch，需指定
.put("client.transport.sniff", true) //自动嗅探
.build();
client = new PreBuiltTransportClient(settings)
//.addTransportAddress(new TransportAddress(InetAddress.getByName("localhost"), 9300));
.addTransportAddress(new TransportAddress(InetAddress.getByName("127.0.0.1"), 9300));
//可用连接设置参数说明
/*
cluster.name
指定集群的名字，如果集群的名字不是默认的elasticsearch，需指定。
client.transport.sniff
设置为true,将自动嗅探整个集群，自动加入集群的节点到连接列表中。
client.transport.ignore_cluster_name
Set to true to ignore cluster name validation of connected nodes. (since 0.19.4)
client.transport.ping_timeout
The time to wait for a ping response from a node. Defaults to 5s.
client.transport.nodes_sampler_interval
How often to sample / ping the nodes listed and connected. Defaults to 5s.
*/
}
return client;
}
}注意使用ES的客户端时类比之前我们在Kibana进行的ES的相关操作，这样使用起来更加有效果
1. Create index 创建索引
CreateIndexDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import org.elasticsearch.action.admin.indices.alias.Alias;
import org.elasticsearch.action.admin.indices.create.CreateIndexRequest;
import org.elasticsearch.action.admin.indices.create.CreateIndexResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.XContentType;
public class CreateIndexDemo {
public static void main(String[] args) {
//这里和RESTful风格不同
try (TransportClient client = InitDemo.getClient();) {
// 1、创建 创建索引request
CreateIndexRequest request = new CreateIndexRequest("mess");
// 2、设置索引的settings
request.settings(Settings.builder().put("index.number_of_shards", 3) // 分片数
.put("index.number_of_replicas", 2) // 副本数
.put("analysis.analyzer.default.tokenizer", "ik_smart") // 默认分词器
);
// 3、设置索引的mappings
request.mapping("_doc",
" {\n" +
" \"_doc\": {\n" +
" \"properties\": {\n" +
" \"message\": {\n" +
" \"type\": \"text\"\n" +
" }\n" +
" }\n" +
" }\n" +
" }",
XContentType.JSON);
// 4、 设置索引的别名
request.alias(new Alias("mmm"));
// 5、 发送请求 这里和RESTful风格不同
CreateIndexResponse createIndexResponse = client.admin().indices()
.create(request).get();
// 6、处理响应
boolean acknowledged = createIndexResponse.isAcknowledged();
boolean shardsAcknowledged = createIndexResponse
.isShardsAcknowledged();
System.out.println("acknowledged = " + acknowledged);
System.out.println("shardsAcknowledged = " + shardsAcknowledged);
// listener方式发送请求
/*ActionListener<CreateIndexResponse> listener = new ActionListener<CreateIndexResponse>() {
@Override
public void onResponse(
CreateIndexResponse createIndexResponse) {
// 6、处理响应
boolean acknowledged = createIndexResponse.isAcknowledged();
boolean shardsAcknowledged = createIndexResponse
.isShardsAcknowledged();
System.out.println("acknowledged = " + acknowledged);
System.out.println(
"shardsAcknowledged = " + shardsAcknowledged);
}
@Override
public void onFailure(Exception e) {
System.out.println("创建索引异常：" + e.getMessage());
}
};
client.admin().indices().create(request, listener);
*/
} catch (IOException | InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
}2. index document
索引文档，即往索引里面放入文档数据.类似于数据库里面向表里面插入一行数据，一行数据就是一个文档
IndexDocumentDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.support.replication.ReplicationResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.rest.RestStatus;
public class IndexDocumentDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
//这里和RESTful风格不同
try (TransportClient client = InitDemo.getClient();) {
// 1、创建索引请求
IndexRequest request = new IndexRequest(
"mess", //索引
"_doc", // mapping type
"11"); //文档id
// 2、准备文档数据
// 方式一：直接给JSON串
String jsonString = "{" +
"\"user\":\"kimchy\"," +
"\"postDate\":\"2013-01-30\"," +
"\"message\":\"trying out Elasticsearch\"" +
"}";
request.source(jsonString, XContentType.JSON);
// 方式二：以map对象来表示文档
/*
Map<String, Object> jsonMap = new HashMap<>();
jsonMap.put("user", "kimchy");
jsonMap.put("postDate", new Date());
jsonMap.put("message", "trying out Elasticsearch");
request.source(jsonMap);
*/
// 方式三：用XContentBuilder来构建文档
/*
XContentBuilder builder = XContentFactory.jsonBuilder();
builder.startObject();
{
builder.field("user", "kimchy");
builder.field("postDate", new Date());
builder.field("message", "trying out Elasticsearch");
}
builder.endObject();
request.source(builder);
*/
// 方式四：直接用key-value对给出
/*
request.source("user", "kimchy",
"postDate", new Date(),
"message", "trying out Elasticsearch");
*/
//3、其他的一些可选设置
/*
request.routing("routing"); //设置routing值
request.timeout(TimeValue.timeValueSeconds(1)); //设置主分片等待时长
request.setRefreshPolicy("wait_for"); //设置重刷新策略
request.version(2); //设置版本号
request.opType(DocWriteRequest.OpType.CREATE); //操作类别
*/
//4、发送请求
IndexResponse indexResponse = null;
try {
//方式一： 用client.index 方法，返回是 ActionFuture<IndexResponse>，再调用get获取响应结果
indexResponse = client.index(request).get();
//方式二：client提供了一个 prepareIndex方法，内部为我们创建IndexRequest
/*IndexResponse indexResponse = client.prepareIndex("mess","_doc","11")
.setSource(jsonString, XContentType.JSON)
.get();*/
//方式三：request + listener
//client.index(request, listener);
} catch(ElasticsearchException e) {
// 捕获，并处理异常
//判断是否版本冲突、create但文档已存在冲突
if (e.status() == RestStatus.CONFLICT) {
logger.error("冲突了，请在此写冲突处理逻辑！\n" + e.getDetailedMessage());
}
logger.error("索引异常", e);
}catch (InterruptedException | ExecutionException e) {
logger.error("索引异常", e);
}
//5、处理响应
if(indexResponse != null) {
String index = indexResponse.getIndex();
String type = indexResponse.getType();
String id = indexResponse.getId();
long version = indexResponse.getVersion();
if (indexResponse.getResult() == DocWriteResponse.Result.CREATED) {
System.out.println("新增文档成功，处理逻辑代码写到这里。");
} else if (indexResponse.getResult() == DocWriteResponse.Result.UPDATED) {
System.out.println("修改文档成功，处理逻辑代码写到这里。");
}
// 分片处理信息
ReplicationResponse.ShardInfo shardInfo = indexResponse.getShardInfo();
if (shardInfo.getTotal() != shardInfo.getSuccessful()) {
}
// 如果有分片副本失败，可以获得失败原因信息
if (shardInfo.getFailed() > 0) {
for (ReplicationResponse.ShardInfo.Failure failure : shardInfo.getFailures()) {
String reason = failure.reason();
System.out.println("副本失败原因：" + reason);
}
}
}
//listener 方式
/*ActionListener<IndexResponse> listener = new ActionListener<IndexResponse>() {
@Override
public void onResponse(IndexResponse indexResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.index(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}3. get document
获取文档数据
GetDocumentDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.Strings;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
public class GetDocumentDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
//这里和RESTful风格不同
try (TransportClient client = InitDemo.getClient();) {
// 1、创建获取文档请求
GetRequest request = new GetRequest(
"mess", //索引
"_doc", // mapping type
"11"); //文档id
// 2、可选的设置
//request.routing("routing");
//request.version(2);
//request.fetchSourceContext(new FetchSourceContext(false)); //是否获取_source字段
//选择返回的字段
String[] includes = new String[]{"message", "*Date"};
String[] excludes = Strings.EMPTY_ARRAY;
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);
//也可写成这样
/*String[] includes = Strings.EMPTY_ARRAY;
String[] excludes = new String[]{"message"};
FetchSourceContext fetchSourceContext = new FetchSourceContext(true, includes, excludes);
request.fetchSourceContext(fetchSourceContext);*/
// 取stored字段
/*request.storedFields("message");
GetResponse getResponse = client.get(request);
String message = getResponse.getField("message").getValue();*/
//3、发送请求
GetResponse getResponse = null;
try {
getResponse = client.get(request).get();
} catch (ElasticsearchException e) {
if (e.status() == RestStatus.NOT_FOUND) {
logger.error("没有找到该id的文档" );
}
if (e.status() == RestStatus.CONFLICT) {
logger.error("获取时版本冲突了，请在此写冲突处理逻辑！" );
}
logger.error("获取文档异常", e);
}catch (InterruptedException | ExecutionException e) {
logger.error("索引异常", e);
}
//4、处理响应
if(getResponse != null) {
String index = getResponse.getIndex();
String type = getResponse.getType();
String id = getResponse.getId();
if (getResponse.isExists()) { // 文档存在
long version = getResponse.getVersion();
String sourceAsString = getResponse.getSourceAsString(); //结果取成 String
Map<String, Object> sourceAsMap = getResponse.getSourceAsMap(); // 结果取成Map
byte[] sourceAsBytes = getResponse.getSourceAsBytes(); //结果取成字节数组
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info(sourceAsString);
} else {
logger.error("没有找到该id的文档" );
}
}
//异步方式发送获取文档请求
/*
ActionListener<GetResponse> listener = new ActionListener<GetResponse>() {
@Override
public void onResponse(GetResponse getResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.getAsync(request, listener);
*/
} catch (IOException e) {
e.printStackTrace();
}
}
}4. Bulk
批量索引文档，即批量往索引里面放入文档数据.类似于数据库里面批量向表里面插入多行数据，一行数据就是一个文档
BulkDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.DocWriteRequest;
import org.elasticsearch.action.DocWriteResponse;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.xcontent.XContentType;
public class BulkDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
//这里和RESTful风格不同
try (TransportClient client = InitDemo.getClient();) {
// 1、创建批量操作请求
BulkRequest request = new BulkRequest();
request.add(new IndexRequest("mess", "_doc", "1")
.source(XContentType.JSON,"field", "foo"));
request.add(new IndexRequest("mess", "_doc", "2")
.source(XContentType.JSON,"field", "bar"));
request.add(new IndexRequest("mess", "_doc", "3")
.source(XContentType.JSON,"field", "baz"));
/*
request.add(new DeleteRequest("mess", "_doc", "3"));
request.add(new UpdateRequest("mess", "_doc", "2")
.doc(XContentType.JSON,"other", "test"));
request.add(new IndexRequest("mess", "_doc", "4")
.source(XContentType.JSON,"field", "baz"));
*/
// 2、可选的设置
/*
request.timeout("2m");
request.setRefreshPolicy("wait_for");
request.waitForActiveShards(2);
*/
//3、发送请求
// 同步请求
BulkResponse bulkResponse = client.bulk(request).get();
//4、处理响应
if(bulkResponse != null) {
for (BulkItemResponse bulkItemResponse : bulkResponse) {
DocWriteResponse itemResponse = bulkItemResponse.getResponse();
if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.INDEX
|| bulkItemResponse.getOpType() == DocWriteRequest.OpType.CREATE) {
IndexResponse indexResponse = (IndexResponse) itemResponse;
//TODO 新增成功的处理
} else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.UPDATE) {
UpdateResponse updateResponse = (UpdateResponse) itemResponse;
//TODO 修改成功的处理
} else if (bulkItemResponse.getOpType() == DocWriteRequest.OpType.DELETE) {
DeleteResponse deleteResponse = (DeleteResponse) itemResponse;
//TODO 删除成功的处理
}
}
}
//异步方式发送批量操作请求
/*
ActionListener<BulkResponse> listener = new ActionListener<BulkResponse>() {
@Override
public void onResponse(BulkResponse bulkResponse) {
}
@Override
public void onFailure(Exception e) {
}
};
client.bulkAsync(request, listener);
*/
} catch (IOException | InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
}5. search
搜索数据
SearchDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.search.ShardSearchFailure;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
public class SearchDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (TransportClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("bank");
searchRequest.types("_doc");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构造QueryBuilder
/*QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("user", "kimchy")
.fuzziness(Fuzziness.AUTO)
.prefixLength(3)
.maxExpansions(10);
sourceBuilder.query(matchQueryBuilder);*/
sourceBuilder.query(QueryBuilders.termQuery("age", 24));
sourceBuilder.from(0);
sourceBuilder.size(10);
sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));
//是否返回_source字段
//sourceBuilder.fetchSource(false);
//设置返回哪些字段
/*String[] includeFields = new String[] {"title", "user", "innerObject.*"};
String[] excludeFields = new String[] {"_type"};
sourceBuilder.fetchSource(includeFields, excludeFields);*/
//指定排序
//sourceBuilder.sort(new ScoreSortBuilder().order(SortOrder.DESC));
//sourceBuilder.sort(new FieldSortBuilder("_uid").order(SortOrder.ASC));
// 设置返回 profile
//sourceBuilder.profile(true);
//将请求体加入到请求中
searchRequest.source(sourceBuilder);
// 可选的设置
//searchRequest.routing("routing");
// 高亮设置
/*
HighlightBuilder highlightBuilder = new HighlightBuilder();
HighlightBuilder.Field highlightTitle =
new HighlightBuilder.Field("title");
highlightTitle.highlighterType("unified");
highlightBuilder.field(highlightTitle);
HighlightBuilder.Field highlightUser = new HighlightBuilder.Field("user");
highlightBuilder.field(highlightUser);
sourceBuilder.highlighter(highlightBuilder);*/
//加入聚合
/*TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_company")
.field("company.keyword");
aggregation.subAggregation(AggregationBuilders.avg("average_age")
.field("age"));
sourceBuilder.aggregation(aggregation);*/
//做查询建议
/*SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.termSuggestion("user").text("kmichy");
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);*/
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest).get();
//4、处理响应
//搜索结果状态信息
RestStatus status = searchResponse.status();
TimeValue took = searchResponse.getTook();
Boolean terminatedEarly = searchResponse.isTerminatedEarly();
boolean timedOut = searchResponse.isTimedOut();
//分片搜索情况
int totalShards = searchResponse.getTotalShards();
int successfulShards = searchResponse.getSuccessfulShards();
int failedShards = searchResponse.getFailedShards();
for (ShardSearchFailure failure : searchResponse.getShardFailures()) {
// failures should be handled here
}
//处理搜索命中文档结果
SearchHits hits = searchResponse.getHits();
long totalHits = hits.getTotalHits();
float maxScore = hits.getMaxScore();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
// do something with the SearchHit
String index = hit.getIndex();
String type = hit.getType();
String id = hit.getId();
float score = hit.getScore();
//取_source字段值
String sourceAsString = hit.getSourceAsString(); //取成json串
Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
//从map中取字段值
/*
String documentTitle = (String) sourceAsMap.get("title");
List<Object> users = (List<Object>) sourceAsMap.get("user");
Map<String, Object> innerObject = (Map<String, Object>) sourceAsMap.get("innerObject");
*/
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info(sourceAsString);
//取高亮结果
/*Map<String, HighlightField> highlightFields = hit.getHighlightFields();
HighlightField highlight = highlightFields.get("title");
Text[] fragments = highlight.fragments();
String fragmentString = fragments[0].string();*/
}
// 获取聚合结果
/*
Aggregations aggregations = searchResponse.getAggregations();
Terms byCompanyAggregation = aggregations.get("by_company");
Bucket elasticBucket = byCompanyAggregation.getBucketByKey("Elastic");
Avg averageAge = elasticBucket.getAggregations().get("average_age");
double avg = averageAge.getValue();
*/
// 获取建议结果
/*Suggest suggest = searchResponse.getSuggest();
TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user");
for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
for (TermSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
}
}
*/
//异步方式发送获查询请求
/*
ActionListener<SearchResponse> listener = new ActionListener<SearchResponse>() {
@Override
public void onResponse(SearchResponse getResponse) {
//结果获取
}
@Override
public void onFailure(Exception e) {
//失败处理
}
};
client.searchAsync(searchRequest, listener);
*/
} catch (IOException | InterruptedException | ExecutionException e) {
logger.error(e);
}
}
}6. highlight 高亮
HighlightDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
public class HighlightDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (TransportClient client = InitDemo.getClient();) {
// 1、创建search请求
SearchRequest searchRequest = new SearchRequest("hl_test");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
//构造QueryBuilder
QueryBuilder matchQueryBuilder = QueryBuilders.matchQuery("title", "lucene solr");
sourceBuilder.query(matchQueryBuilder);
//分页设置
/*sourceBuilder.from(0);
sourceBuilder.size(5); ;*/
// 高亮设置
HighlightBuilder highlightBuilder = new HighlightBuilder();
highlightBuilder.requireFieldMatch(false).field("title").field("content")
.preTags("<strong>").postTags("</strong>");
//不同字段可有不同设置，如不同标签
/*HighlightBuilder.Field highlightTitle = new HighlightBuilder.Field("title");
highlightTitle.preTags("<strong>").postTags("</strong>");
highlightBuilder.field(highlightTitle);
HighlightBuilder.Field highlightContent = new HighlightBuilder.Field("content");
highlightContent.preTags("<b>").postTags("</b>");
highlightBuilder.field(highlightContent).requireFieldMatch(false);*/
sourceBuilder.highlighter(highlightBuilder);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest).get();
//4、处理响应
if(RestStatus.OK.equals(searchResponse.status())) {
//处理搜索命中文档结果
SearchHits hits = searchResponse.getHits();
long totalHits = hits.getTotalHits();
SearchHit[] searchHits = hits.getHits();
for (SearchHit hit : searchHits) {
String index = hit.getIndex();
String type = hit.getType();
String id = hit.getId();
float score = hit.getScore();
//取_source字段值
//String sourceAsString = hit.getSourceAsString(); //取成json串
Map<String, Object> sourceAsMap = hit.getSourceAsMap(); // 取成map对象
//从map中取字段值
/*String title = (String) sourceAsMap.get("title");
String content = (String) sourceAsMap.get("content"); */
logger.info("index:" + index + " type:" + type + " id:" + id);
logger.info("sourceMap : " + sourceAsMap);
//取高亮结果
Map<String, HighlightField> highlightFields = hit.getHighlightFields();
HighlightField highlight = highlightFields.get("title");
if(highlight != null) {
Text[] fragments = highlight.fragments(); //多值的字段会有多个值
if(fragments != null) {
String fragmentString = fragments[0].string();
logger.info("title highlight : " + fragmentString);
//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
//sourceAsMap.put("title", fragmentString);
}
}
highlight = highlightFields.get("content");
if(highlight != null) {
Text[] fragments = highlight.fragments(); //多值的字段会有多个值
if(fragments != null) {
String fragmentString = fragments[0].string();
logger.info("content highlight : " + fragmentString);
//可用高亮字符串替换上面sourceAsMap中的对应字段返回到上一级调用
//sourceAsMap.put("content", fragmentString);
}
}
}
}
} catch (IOException | InterruptedException | ExecutionException e) {
logger.error(e);
}
}
}7. suggest 查询建议
SuggestDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.SuggestBuilder;
import org.elasticsearch.search.suggest.SuggestBuilders;
import org.elasticsearch.search.suggest.SuggestionBuilder;
import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
import org.elasticsearch.search.suggest.term.TermSuggestion;
public class SuggestDemo {
private static Logger logger = LogManager.getRootLogger();
//拼写检查
public static void termSuggest(TransportClient client) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("mess");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//做查询建议
//词项建议
SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.termSuggestion("user").text("kmichy");
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("suggest_user", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);
searchRequest.source(sourceBuilder);
try{
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest).get();
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取建议结果
Suggest suggest = searchResponse.getSuggest();
TermSuggestion termSuggestion = suggest.getSuggestion("suggest_user");
for (TermSuggestion.Entry entry : termSuggestion.getEntries()) {
logger.info("text: " + entry.getText().string());
for (TermSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
logger.info(" suggest option : " + suggestText);
}
}
}
} catch (InterruptedException | ExecutionException e) {
logger.error(e);
}
/*
"suggest": {
"my-suggestion": [
{
"text": "tring",
"offset": 0,
"length": 5,
"options": [
{
"text": "trying",
"score": 0.8,
"freq": 1
}
]
},
{
"text": "out",
"offset": 6,
"length": 3,
"options": []
},
{
"text": "elasticsearch",
"offset": 10,
"length": 13,
"options": []
}
]
}*/
}
//自动补全
public static void completionSuggester(TransportClient client) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("music");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//做查询建议
//自动补全
/*POST music/_search?pretty
{
"suggest": {
"song-suggest" : {
"prefix" : "lucene s",
"completion" : {
"field" : "suggest" ,
"skip_duplicates": true
}
}
}
}*/
SuggestionBuilder termSuggestionBuilder =
SuggestBuilders.completionSuggestion("suggest").prefix("lucene s")
.skipDuplicates(true);
SuggestBuilder suggestBuilder = new SuggestBuilder();
suggestBuilder.addSuggestion("song-suggest", termSuggestionBuilder);
sourceBuilder.suggest(suggestBuilder);
searchRequest.source(sourceBuilder);
try {
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest).get();
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取建议结果
Suggest suggest = searchResponse.getSuggest();
CompletionSuggestion termSuggestion = suggest.getSuggestion("song-suggest");
for (CompletionSuggestion.Entry entry : termSuggestion.getEntries()) {
logger.info("text: " + entry.getText().string());
for (CompletionSuggestion.Entry.Option option : entry) {
String suggestText = option.getText().string();
logger.info(" suggest option : " + suggestText);
}
}
}
} catch (InterruptedException | ExecutionException e) {
logger.error(e);
}
}
public static void main(String[] args) {
try (TransportClient client = InitDemo.getClient();) {
termSuggest(client);
logger.info("--------------------------------------");
completionSuggester(client);
} catch (IOException e) {
logger.error(e);
}
}
}8. aggregation 聚合分析
AggregationDemo.java
package com.study.es_java_client;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.transport.TransportClient;
import org.elasticsearch.rest.RestStatus;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.Aggregations;
import org.elasticsearch.search.aggregations.BucketOrder;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms.Bucket;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.aggregations.metrics.avg.Avg;
import org.elasticsearch.search.builder.SearchSourceBuilder;
public class AggregationDemo {
private static Logger logger = LogManager.getRootLogger();
public static void main(String[] args) {
try (TransportClient client = InitDemo.getClient();) {
// 1、创建search请求
//SearchRequest searchRequest = new SearchRequest();
SearchRequest searchRequest = new SearchRequest("bank");
// 2、用SearchSourceBuilder来构造查询请求体 ,请仔细查看它的方法，构造各种查询的方法都在这。
SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
sourceBuilder.size(0);
//加入聚合
//字段值项分组聚合
TermsAggregationBuilder aggregation = AggregationBuilders.terms("by_age")
.field("age").order(BucketOrder.aggregation("average_balance", true));
//计算每组的平均balance指标
aggregation.subAggregation(AggregationBuilders.avg("average_balance")
.field("balance"));
sourceBuilder.aggregation(aggregation);
searchRequest.source(sourceBuilder);
//3、发送请求
SearchResponse searchResponse = client.search(searchRequest).get();
//4、处理响应
//搜索结果状态信息
if(RestStatus.OK.equals(searchResponse.status())) {
// 获取聚合结果
Aggregations aggregations = searchResponse.getAggregations();
Terms byAgeAggregation = aggregations.get("by_age");
logger.info("aggregation by_age 结果");
logger.info("docCountError: " + byAgeAggregation.getDocCountError());
logger.info("sumOfOtherDocCounts: " + byAgeAggregation.getSumOfOtherDocCounts());
logger.info("------------------------------------");
for(Bucket buck : byAgeAggregation.getBuckets()) {
logger.info("key: " + buck.getKeyAsNumber());
logger.info("docCount: " + buck.getDocCount());
//logger.info("docCountError: " + buck.getDocCountError());
//取子聚合
Avg averageBalance = buck.getAggregations().get("average_balance");
logger.info("average_balance: " + averageBalance.getValue());
logger.info("------------------------------------");
}
//直接用key 来去分组
/*Bucket elasticBucket = byCompanyAggregation.getBucketByKey("24");
Avg averageAge = elasticBucket.getAggregations().get("average_age");
double avg = averageAge.getValue();*/
}
} catch (IOException | InterruptedException | ExecutionException e) {
logger.error(e);
}
}
}9. 官网文档
Document API 文档操作API：
https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-docs.html
Search API：
https://www.elastic.co/guide/en/elasticsearch/client/java-api/6.2/java-search.html
六、Spring Data Elasticsearch
ES与Spring集成使用，可以作为了解，个人建议还是使用原生的ES的java客户端
官网链接：
https://docs.spring.io/spring-data/elasticsearch/docs/current/reference/html/
代码库：
https://github.com/spring-projects/spring-data-elasticsearch
七、源代码获取地址
https://github.com/leeSmall/Elasticsearch-Java-client-api
转自：https://www.cnblogs.com/leeSmall/p/9218779.html
注:想学习es相关知识，请到https://www.cnblogs.com/leeSmall/p/9218779.html连接下查找详细信息，该博客写的很好
今天的关于一般 JAVA 高级工程师的知识深度？和一般 java 高级工程师的知识深度是多少的分享已经结束，谢谢您的关注，如果想了解更多关于4-1 如何定义 Java 中的方法；Java 中无参无返回值方法的使用；Java 中无参带返回值方法的使用；、5-2 Java 中的 static 使用之静态变量 ;;Java 中的 static 使用之静态方法;;Java 中的 static 使用之静态初始化块、ArrayMap java.lang.ClassCastException: java.lang.String cannot be cast to java.lang.Object[]、Elasticsearch Java client（ES Client 简介、Java REST Client、Java Client、Spring Data Elasticsearch）的相关知识，请在本站进行查询。
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