这篇文章主要围绕如何使用Java以CSV格式导出数据？和javacsv导出展开，旨在为您提供一份详细的参考资料。我们将全面介绍如何使用Java以CSV格式导出数据？的优缺点，解答javacsv导出的相

这篇文章主要围绕如何使用Java以CSV格式导出数据？和java csv导出展开，旨在为您提供一份详细的参考资料。我们将全面介绍如何使用Java以CSV格式导出数据？的优缺点，解答java csv导出的相关问题，同时也会为您带来bash – 如何在AWK中以CSV格式打印一系列列？、c# – 以CSV格式显示逗号而不使用逗号字符、java 导出csv格式、javascript – 如何使用jquery将数据从表导出到csv文件的实用方法。

• 如何使用Java以CSV格式导出数据？（java csv导出）
• bash – 如何在AWK中以CSV格式打印一系列列？
• c# – 以CSV格式显示逗号而不使用逗号字符
• java 导出csv格式
• javascript – 如何使用jquery将数据从表导出到csv文件

如何使用Java以CSV格式导出数据？（java csv导出）

原因可能是Java :(的知识不足），所以我问这个问题，

在这段代码中，我正在从jsp页面获取动态值：

<form action="">  <%     Class.forName("com.mysql.jdbc.Driver");    Connection con = DriverManager.getConnection("jdbc:mysql://localhost/apps","root","root");    Statement stmt = con.createStatement();    String sql = "select * from info;";    ResultSet rs = stmt.executeQuery(sql);    System.out.println(sql);    System.out.println("hi Tirtha");  %>  <center>    <h3>Information of User''s</h3>    <table cellpadding="4" cellspacing="2" border="1" bgcolor="">      <tr>        <th>User Name</th>        <th>Email Id</th>      </tr>      <tr>        <%while(rs.next()){%>          <td><input type="text" name="name" value="<%= rs.getString(1)%>" readonly="readonly">          <td><input type="text" name="email" value="<%= rs.getString(2)%>" readonly="readonly">          </tr>        <%}%>    </table>  </center></form>

现在，我想将此数据保存在一个csv文件中 （其中具有导出选项）。

任何输入将不胜感激。

答案1

这是您可以用来导出为CSV的类：

import java.io.FileWriter;import java.io.IOException;import User; public class GenerateCsv {    private static void generateCsvFile(ArrayList<User> users)    {        String output = "Email, Name\n";        for (User user in users) {            output += user.getEmail() + ", " + user.getName() + "\n";        }        return output;    } }

以MVC方式工作

这是编写代码的方式：

假设您有一个名为的类。 User.java 中有一个名为get all users的静态函数。

public class User {    String name;    String email;    public static ArrayList<User> getAllUsers() {        // returns all users        ...     }}

然后，假设您有一个名为UsersServlet的servlet，它可以获取这些用户：

import javax.servlet.*;import javax.servlet.http.*;public class UsersServlet extends HttpServlet {    public void doGet (HttpServletRequest   req, HttpServletResponse  res)        throws ServletException, IOException {        res.setContentType("application/csv");        PrintWriter w = res.getWriter();        ArrayList<User> users = Users.getAllUsers();        w.prinln(GenerateCsv.generateCsvFile(users));        w.flush();        w.close();    }    public void doPost (HttpServletRequest  req, HttpServletResponse  res)        throws ServletException, IOException {        ...    }}

例如，在您的jsp中，您将有一个简单的锚标记，该标记调用servlet（这些servlet调用User.java，获取数据，将它们形成CSV，然后将其输出到浏览器…）。这样的事情会起作用：

<a href=''/getCSV'' > Export CSV </a>

但请注意，您必须使用web.xml 将servlet链接到 url ：

<web-app>    <servlet>        <servlet-name>UsersServlet</servlet-name>        <servlet-class>__package__.UsersServlet</servlet-class>    </servlet>    <servlet-mapping>        <servlet-name>UsersServlet</servlet-name>    <url-pattern>getCSV</url-pattern>    </servlet-mapping></web-app>

编辑：写入磁盘而不是发送到浏览器

 import java.io.FileWriter; import java.io.IOException; import User; public class GenerateCsv {    private static void generateCsvFile(String fileName, ArrayList<User> users)    {           try           {                FileWriter writer = new FileWriter(fileName);                writer.append("Email");                writer.append('','');                writer.append("Name");                writer.append(''\n'');                for (User user in users) {                     writer.append(user.getEmail());                     writer.append('','');                     writer.append(user.getName());                     writer.append(''\n'');                }                writer.flush();                writer.close();           } catch(IOException e) {                 e.printStackTrace();           }       } }

bash – 如何在AWK中以CSV格式打印一系列列？

awk -F,'{ print $10 }' file.csv

awk -F,'{ print $5","$6","$7","$8","$9","$10 }' file.csv

awk -v s=5 -v e=10 'BEGIN{FS=OFS=","}{for (i=s; i<=e; ++i) printf "%s%s",$i,(i<e?OFS:ORS)}' file

cut -d,-f5-10 file

perl -F,-lane '$"=","; print "@F[4..9]"' file

c# – 以CSV格式显示逗号而不使用逗号字符

static public string CsvQuote(this string text)
{
    if (text == null) return string.Empty;

    bool containsQuote = false;
    bool containsComma = false;
    int len = text.Length;

    for (int i = 0; i < len && (containsComma == false || containsQuote == false); i++)
    {
        char ch = text[i];
        if (ch == '"')
        {
            containsQuote = true;
        }
        else if (ch == ',' || char.IsControl(ch))
        {
            containsComma = true;
        }
    }

    bool mustQuote = containsComma || containsQuote;

    if (containsQuote)
    {
        text = text.Replace("\"","\"\"");
    }

    // Quote the cell and replace embedded quotes with double-quote or just return as is
    return mustQuote ? "\"" + text + "\"" : text;
}

logger.Write(myString.CsvQuote());

var csv = string.Join(",",listofStrings.Select(CsvQuote))

java 导出csv格式

java 导出csv

本demo地址：https://github.com/woyaochengweidaniu/javaEE/tree/master/file-handling

依赖

  <!-- https://mvnrepository.com/artifact/com.univocity/univocity-parsers -->
        <dependency>
            <groupId>com.univocity</groupId>
            <artifactId>univocity-parsers</artifactId>
            <version>2.8.2</version>
        </dependency>

代码分层使用mybatisplus自动生成

工具类

package com.example.easyexcel.util;

import com.univocity.parsers.csv.CsvWriter;
import com.univocity.parsers.csv.CsvWriterSettings;

import java.io.*;
import java.util.List;

/**
 * @author lcm
 */
public class CsvUtils {

    public static void simpleExport(boolean quoteAllFields, String lineSeparator, String[] heads, List<Object[]> data, String fileName, OutputStream outputStream) throws UnsupportedEncodingException {
        CsvWriterSettings settings = new CsvWriterSettings();
        settings.setQuoteAllFields(quoteAllFields);
        //分割线使用系统默认
        settings.getFormat().setLineSeparator(lineSeparator);
        settings.setIgnoreLeadingWhitespaces(false);
        settings.setIgnoreTrailingWhitespaces(false);
        settings.setHeaders(heads);
        OutputStream csvResult = outputStream;
        //FileOutputStream csvResult =  new FileOutputStream("C:\\temp\\test.csv");
        //ByteArrayOutputStream csvResult = new ByteArrayOutputStream();

        CsvWriter writer = new CsvWriter(new OutputStreamWriter(csvResult, "UTF-8"), settings);

        writer.writeHeaders();
       writer.writeRows(data);
        writer.close();
        try {
            csvResult.close();
        } catch (IOException e) {
            e.printStackTrace();
        }


    }
}

调用， 没有处理业务 直接调用

package com.example.easyexcel.cvs;



import cn.hutool.core.util.URLUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.example.easyexcel.work.service.IUserService;
import com.example.easyexcel.util.CollectionUtil;
import com.example.easyexcel.util.CsvUtils;
import com.univocity.parsers.csv.CsvParser;
import com.univocity.parsers.csv.CsvParserSettings;
import org.apache.poi.util.StringUtil;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
import java.util.Map;


/**
 *
 * 项目源码 ：   https://github.com/uniVocity/univocity-parsers
 *
 * maven地址：
 *          <dependency>
 *             <groupId>com.univocity</groupId>
 *             <artifactId>univocity-parsers</artifactId>
 *             <version>2.8.2</version>
 *         </dependency>
 *
 * @author lcm
 */
@RestController
public class CvsController {

    @Autowired
    private IUserService userService;

    /**
     * 导出CVS
     * @param response
     * @throws IOException
     */
    @GetMapping("exportCSV")
    public void exportCVS(HttpServletResponse response) throws IOException {
        ServletOutputStream csvResult = response.getOutputStream();
        response.setContentType("multipart/form-data");
        response.setCharacterEncoding("utf-8");
        response.setHeader("Content-disposition", "attachment;filename="+ URLUtil.encode("test", StringUtil.UTF8) +".csv");
        String[] head = new String[]{"用户姓名","年龄","性别","地址","手机号","业余爱好","出生日期","创建时间"};
        List<Map<String, Object>> list = userService.listMaps(new QueryWrapper<>());
        List<Object[]> objects = CollectionUtil.collectToArray(list);
        CsvUtils.simpleExport(true,"\n",head,objects,"test",csvResult);
    }

    /**
     * 导入CVS
     * @param file
     * @return
     * @throws IOException
     */
    @PostMapping("importCSV")
    public Object uploadCSV(MultipartFile file) throws IOException {
        //##CODE_START

        CsvParserSettings settings = new CsvParserSettings();
        //the file used in the example uses ''\n'' as the line separator sequence.
        //the line separator sequence is defined here to ensure systems such as MacOS and Windows
        //are able to process this file correctly (MacOS uses ''\r''; and Windows uses ''\r\n'').
        settings.getFormat().setLineSeparator("\n");
        // creates a CSV parser  如果CSV经过Excel打开后文本格式发生改变，导入进来的是乱码
        CsvParser parser = new CsvParser(settings);

        // parses all rows in one go.
        List<String[]> allRows = parser.parseAll(file.getInputStream(),10000);

        for (String[] strings:allRows) {
            System.out.println(Arrays.toString(strings));
        }
        return "success";
    }



}

javascript – 如何使用jquery将数据从表导出到csv文件

我正在尝试从数据表导出到CSV文件.这是我的全部功能.它下载一个文件,但它显示了表的整个代码,并没有将任何数据分开.当我说整个代码时,我指的是’table / table’中的所有内容@H_301_1@

@H_301_1@

function displayDataTable(index){
$("#pageOverlay").empty();
    html = "<div id='volumeChartDiv'><h4>Data Table</h4><table id='dataTable'role='grid'><thead><tr role='row'><th>header1</th><th>header2</th><th>header3</th></tr></thead><tbody><tr><td>cell1-1</td><td>cell1-2</td><td>cell1-3</td></tr><tr><td>bell2-1</td><td>bell2-2</td><td>bell2-3</td></tr><tr><td>fell3-1</td><td>fell3-2</td><td>fell3-3</td></tr></tbody></table><input type='button' value='Close' onclick='cloSEOverlay()'>&nbsp;&nbsp;<input type='button' id='exportDataTable' value='Export Table'></div>";
  $("#pageOverlay").html(html);
// export data function    
  $("#exportDataTable").click(function (e) {
      window.open('data:application/vnd.ms-excel,' + $('.dataTable').html());
      e.preventDefault();
});
   openOverlay();
}

解决方法:@H_301_1@

CSV格式不能接受$(‘.dataTable’).html()as .html()不是结构化数据,它甚至不是数据,只是一个愚蠢的hmtl.@H_301_1@

你必须从你的表中获取数据,创建一个表示CSV格式的字符串,然后下载它,因为你没有在下面显示你的表格数据结构的工作演示@H_301_1@

@H_301_1@

$('#export').click(function() {
  var titles = [];
  var data = [];

  /*
   * Get the table headers, this will be CSV headers
   * The count of headers will be CSV string separator
   */
  $('.dataTable th').each(function() {
    titles.push($(this).text());
  });

  /*
   * Get the actual data, this will contain all the data, in 1 array
   */
  $('.dataTable td').each(function() {
    data.push($(this).text());
  });
  
  /*
   * Convert our data to CSV string
   */
  var CSVString = prepCSVRow(titles, titles.length, '');
  CSVString = prepCSVRow(data, titles.length, CSVString);

  /*
   * Make CSV downloadable
   */
  var downloadLink = document.createElement("a");
  var blob = new Blob(["\ufeff", CSVString]);
  var url = URL.createObjectURL(blob);
  downloadLink.href = url;
  downloadLink.download = "data.csv";

  /*
   * Actually download CSV
   */
  document.body.appendChild(downloadLink);
  downloadLink.click();
  document.body.removeChild(downloadLink);
});

   /*
* Convert data array to CSV string
* @param arr {Array} - the actual data
* @param columnCount {Number} - the amount to split the data into columns
* @param initial {String} - initial string to append to CSV string
* return {String} - ready CSV string
*/
function prepCSVRow(arr, columnCount, initial) {
  var row = ''; // this will hold data
  var delimeter = ','; // data slice separator, in excel it's `;`, in usual CSv it's `,`
  var newLine = '\r\n'; // newline separator for CSV row

  /*
   * Convert [1,2,3,4] into [[1,2], [3,4]] while count is 2
   * @param _arr {Array} - the actual array to split
   * @param _count {Number} - the amount to split
   * return {Array} - splitted array
   */
  function splitArray(_arr, _count) {
    var splitted = [];
    var result = [];
    _arr.forEach(function(item, idx) {
      if ((idx + 1) % _count === 0) {
        splitted.push(item);
        result.push(splitted);
        splitted = [];
      } else {
        splitted.push(item);
      }
    });
    return result;
  }
  var plainArr = splitArray(arr, columnCount);
  // don't kNow how to explain this
  // you just have to like follow the code
  // and you understand, it's pretty simple
  // it converts `['a', 'b', 'c']` to `a,b,c` string
  plainArr.forEach(function(arrItem) {
    arrItem.forEach(function(item, idx) {
      row += item + ((idx + 1) === arrItem.length ? '' : delimeter);
    });
    row += newLine;
  });
  return initial + row;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<button id="export">export</button>

<table>
  <tr>
    <th>Company</th>
    <th>Contact</th>
    <th>Country</th>
  </tr>
  <tr>
    <td>Alfreds Futterkiste</td>
    <td>Maria Anders</td>
    <td>Germany</td>
  </tr>
  <tr>
    <td>Centro comercial Moctezuma</td>
    <td>Francisco Chang</td>
    <td>Mexico</td>
  </tr>
  <tr>
    <td>Ernst Handel</td>
    <td>Roland Mendel</td>
    <td>Austria</td>
  </tr>
  <tr>
    <td>Island Trading</td>
    <td>Helen Bennett</td>
    <td>UK</td>
  </tr>
  <tr>
    <td>Laughing Bacchus Winecellars</td>
    <td>Yoshi Tannamuri</td>
    <td>Canada</td>
  </tr>
  <tr>
    <td>Magazzini Alimentari Riuniti</td>
    <td>Giovanni Rovelli</td>
    <td>Italy</td>
  </tr>
</table>

如果您发现任何错误,请在下方发表评论,我会修复它们@H_301_1@

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