本文的目的是介绍以编程方式抛出NullPointerException可以吗？的详细情况，特别关注程序抛出异常时只能抛出自己定义的对象的相关信息。我们将通过专业的研究、有关数据的分析等多种方式，为您呈

本文的目的是介绍以编程方式抛出NullPointerException可以吗？的详细情况，特别关注程序抛出异常时只能抛出自己定义的对象的相关信息。我们将通过专业的研究、有关数据的分析等多种方式，为您呈现一个全面的了解以编程方式抛出NullPointerException可以吗？的机会，同时也不会遗漏关于Android gradle插件更新到3.3.0抛出NullPointerException、android – ContentResolver查询抛出nullpointerException、android – 隐藏片段中的actionbar会抛出NullPointerException吗？、Eclipse在Maven更新期间抛出NullPointerException的知识。

• 以编程方式抛出NullPointerException可以吗？（程序抛出异常时只能抛出自己定义的对象）
• Android gradle插件更新到3.3.0抛出NullPointerException
• android – ContentResolver查询抛出nullpointerException
• android – 隐藏片段中的actionbar会抛出NullPointerException吗？
• Eclipse在Maven更新期间抛出NullPointerException

以编程方式抛出NullPointerException可以吗？（程序抛出异常时只能抛出自己定义的对象）

当存在后置条件时，该方法的返回值一定不能为null，该怎么办？

我可以

assert returnValue != null : "Not acceptable null value";

但是断言可以关闭！

那可以吗

if(returnValue==null)      {           throw new NullPointerException("return value is null at method AAA");      }

？

还是针对此类情况使用用户定义的异常（例如NullReturnValueException）更好？

答案1

我认为在JVM为您执行操作之前尽早抛出NPE没问题-特别是对于null参数。对此似乎有一些争论，但是Java
SE库中有许多示例正是这样做的。我不明白为什么NPE在您自己不能扔掉它方面应该是神圣的。

但是，我离题了。这个问题是关于不同的东西。您正在谈论的是后置条件，该条件说明返回值不能为null。在这种情况下，肯定为null意味着您 在very方法内
有一个错误吗？

您甚至将如何记录？“如果返回值意外为null，则此方法将引发NullPointerException”？不解释这怎么可能？不，我在这里使用一个断言。异常应该用于可能发生的错误-
不能覆盖方法内部出现问题时可能发生的事情，因为这对任何人都没有帮助。

Android gradle插件更新到3.3.0抛出NullPointerException

我刚刚更新到Android Studio 3.3并尝试将Gradle插件更新为3.3.0但项目构建失败.

该项目是一个带有应用程序(使用该库)的库.尝试了一切：清除,重建,重置,删除.gradle目录,甚至没有运气重启计算机.任何的想法？

这是堆栈跟踪

org.gradle.api.ProjectConfigurationException: A problem occurred configuring project ':screenz_library'.
    |95 internal calls|
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
    at java.lang.Thread.run(Thread.java:745)
Caused by: com.android.build.gradle.internal.crash.ExternalApiUsageException: java.lang.NullPointerException
    at com.android.build.gradle.internal.ApiObjectFactory.create(ApiObjectFactory.java:137)
    at com.android.build.gradle.BasePlugin.createAndroidTasks(BasePlugin.java:777)
    at com.android.builder.profile.ThreadRecorder.record(ThreadRecorder.java:81)
    at com.android.build.gradle.BasePlugin.lambda$createTasks$4(BasePlugin.java:651)
    at com.android.build.gradle.internal.crash.CrashReporting$afterEvaluate$1.execute(crash_reporting.kt:37)
    at com.android.build.gradle.internal.crash.CrashReporting$afterEvaluate$1.execute(crash_reporting.kt)
    at org.gradle.configuration.internal.DefaultListenerBuildOperationDecorator$BuildOperationEmittingAction$1$1.run(DefaultListenerBuildOperationDecorator.java:155)
    at org.gradle.configuration.internal.DefaultUserCodeApplicationContext.reapply(DefaultUserCodeApplicationContext.java:58)
    at org.gradle.configuration.internal.DefaultListenerBuildOperationDecorator$BuildOperationEmittingAction$1.run(DefaultListenerBuildOperationDecorator.java:152)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:300)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:292)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:174)
    at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
    at org.gradle.configuration.internal.DefaultListenerBuildOperationDecorator$BuildOperationEmittingAction.execute(DefaultListenerBuildOperationDecorator.java:149)
    at org.gradle.internal.event.broadcastdispatch$ActionInvocationHandler.dispatch(broadcastdispatch.java:91)
    at org.gradle.internal.event.broadcastdispatch$ActionInvocationHandler.dispatch(broadcastdispatch.java:80)
    at org.gradle.internal.event.Abstractbroadcastdispatch.dispatch(Abstractbroadcastdispatch.java:42)
    at org.gradle.internal.event.broadcastdispatch$Singletondispatch.dispatch(broadcastdispatch.java:230)
    at org.gradle.internal.event.broadcastdispatch$Singletondispatch.dispatch(broadcastdispatch.java:149)
    at org.gradle.internal.event.Abstractbroadcastdispatch.dispatch(Abstractbroadcastdispatch.java:58)
    at org.gradle.internal.event.broadcastdispatch$Compositedispatch.dispatch(broadcastdispatch.java:324)
    at org.gradle.internal.event.broadcastdispatch$Compositedispatch.dispatch(broadcastdispatch.java:234)
    at org.gradle.internal.event.Listenerbroadcast.dispatch(Listenerbroadcast.java:140)
    at org.gradle.internal.event.Listenerbroadcast.dispatch(Listenerbroadcast.java:37)
    at org.gradle.internal.dispatch.ProxydispatchAdapter$dispatchingInvocationHandler.invoke(ProxydispatchAdapter.java:93)
    at com.sun.proxy.$Proxy29.afterEvaluate(UnkNown Source)
    at org.gradle.configuration.project.LifecycleProjectEvaluator$NotifyAfterEvaluate$1.execute(LifecycleProjectEvaluator.java:187)
    at org.gradle.configuration.project.LifecycleProjectEvaluator$NotifyAfterEvaluate$1.execute(LifecycleProjectEvaluator.java:184)
    at org.gradle.api.internal.project.DefaultProject.stepEvaluationListener(DefaultProject.java:1418)
    at org.gradle.configuration.project.LifecycleProjectEvaluator$NotifyAfterEvaluate.run(LifecycleProjectEvaluator.java:193)
    ... 95 more
Caused by: java.lang.NullPointerException
    at org.gradle.api.internal.tasks.DefaultTaskDependency.add(DefaultTaskDependency.java:185)
    at org.gradle.api.internal.AbstractTask$12.run(AbstractTask.java:430)
    at org.gradle.api.internal.tasks.TaskMutator.mutate(TaskMutator.java:40)
    at org.gradle.api.internal.AbstractTask.dependsOn(AbstractTask.java:428)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSite.invoke(PogoMetaMethodSite.java:169)
    at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.call(PogoMetaMethodSite.java:71)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:128)
    at com.google.gms.googleservices.GoogleServicesPlugin.handleVariant(GoogleServicesPlugin.groovy:206)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at org.gradle.internal.Metaobject.BeanDynamicObject$MetaClassAdapter.invokeMethod(BeanDynamicObject.java:479)
    at org.gradle.internal.Metaobject.BeanDynamicObject.tryInvokeMethod(BeanDynamicObject.java:191)
    at org.gradle.internal.Metaobject.ConfigureDelegate.invokeMethod(ConfigureDelegate.java:78)
    at org.codehaus.groovy.runtime.Metaclass.ClosureMetaClass.invokeOnDelegationObjects(ClosureMetaClass.java:398)
    at org.codehaus.groovy.runtime.Metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:338)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1034)
    at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:68)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:177)
    at com.google.gms.googleservices.GoogleServicesPlugin$_setupPlugin_closure6.doCall(GoogleServicesPlugin.groovy:148)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
    at org.codehaus.groovy.runtime.Metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:264)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1034)
    at groovy.lang.Closure.call(Closure.java:418)
    at groovy.lang.Closure.call(Closure.java:434)
    at org.gradle.api.internal.ClosureBackedAction.execute(ClosureBackedAction.java:71)
    at org.gradle.util.ConfigureUtil.configureTarget(ConfigureUtil.java:155)
    at org.gradle.util.ConfigureUtil.configure(ConfigureUtil.java:106)
    at org.gradle.util.ConfigureUtil$WrappedConfigureAction.execute(ConfigureUtil.java:167)
    at org.gradle.internal.ImmutableActionSet$SingletonSet.execute(ImmutableActionSet.java:225)
    at org.gradle.api.internal.DefaultDomainObjectCollection.doAdd(DefaultDomainObjectCollection.java:244)
    at org.gradle.api.internal.DefaultDomainObjectCollection.add(DefaultDomainObjectCollection.java:233)
    at com.android.build.gradle.LibraryExtension.addVariant(LibraryExtension.java:93)
    at com.android.build.gradle.internal.ApiObjectFactory.create(ApiObjectFactory.java:134)
    ... 124 more

解决方法:

我在尝试其他事情的同时找到了解决方案.
出于某种原因,我在我的图书馆的gradle文件中有了Google Services插件,所以我删除了它并且项目构建没有问题.

我删除了这一行

apply plugin: 'com.google.gms.google-services'

android – ContentResolver查询抛出nullpointerException

Uri uri = Uri.parse("content://mms-sms/conversations/"+String.valueOf(thread_id));
ContentResolver cr = context.getContentResolver();
Cursor c= cr.query(uri,null,null);    //crashing here

05-22 15:24:24.273: E/AndroidRuntime(32087): FATAL EXCEPTION: main
05-22 15:24:24.273: E/AndroidRuntime(32087): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.uiu.messaging/com.uiu.messaging.ContactMessageChain}: java.lang.NullPointerException
05-22 15:24:24.273: E/AndroidRuntime(32087): at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:1816)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1837)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.app.ActivityThread.access$1500(ActivityThread.java:132)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1033)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.os.Looper.loop(Looper.java:143)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.app.ActivityThread.main(ActivityThread.java:4196)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at java.lang.reflect.Method.invokeNative(Native Method)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at java.lang.reflect.Method.invoke(Method.java:507)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at dalvik.system.NativeStart.main(Native Method)
05-22 15:24:24.273: E/AndroidRuntime(32087): Caused by: java.lang.NullPointerException
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.os.Parcel.readException(Parcel.java:1328)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:160)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:114)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.content.ContentProviderProxy.bulkQueryInternal(ContentProviderNative.java:372)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.content.ContentProviderProxy.query(ContentProviderNative.java:408)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.content.ContentResolver.query(ContentResolver.java:264)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at com.uiu.messaging.Data.getContactChain(Data.java:319)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at com.uiu.messaging.ContactMessageChain.onCreate(ContactMessageChain.java:138)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
05-22 15:24:24.273: E/AndroidRuntime(32087):    at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:1780)
05-22 15:24:24.273: E/AndroidRuntime(32087):    ... 11 more

05-22 16:31:46.178: E/AndroidRuntime(1892): FATAL EXCEPTION: main
05-22 16:31:46.178: E/AndroidRuntime(1892): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.uiu.messaging/com.uiu.messaging.ContactMessageChain}: android.database.sqlite.sqliteException: near "*": Syntax error:,while compiling: SELECT * FROM (SELECT disTINCT date * 1 AS normalized_date,NULL AS * FROM sms WHERE (htc_category= 0 AND thread_id = 25 AND (type != 3 AND type > 0)) UNION SELECT disTINCT date * 1000 AS normalized_date,NULL AS * FROM pdu LEFT JOIN pending_msgs ON pdu._id = pending_msgs.msg_id WHERE (htc_category= 0 AND thread_id = 25 AND msg_Box != 3 AND (msg_Box > 0 AND msg_Box != 3 AND (m_type = 128 OR m_type = 132 OR m_type = 130))) ORDER BY normalized_date ASC)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:1816)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1837)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.ActivityThread.access$1500(ActivityThread.java:132)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1033)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.os.Looper.loop(Looper.java:143)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.ActivityThread.main(ActivityThread.java:4196)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at java.lang.reflect.Method.invokeNative(Native Method)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at java.lang.reflect.Method.invoke(Method.java:507)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at dalvik.system.NativeStart.main(Native Method)
05-22 16:31:46.178: E/AndroidRuntime(1892): Caused by: android.database.sqlite.sqliteException: near "*": Syntax error:,NULL AS * FROM pdu LEFT JOIN pending_msgs ON pdu._id = pending_msgs.msg_id WHERE (htc_category= 0 AND thread_id = 25 AND msg_Box != 3 AND (msg_Box > 0 AND msg_Box != 3 AND (m_type = 128 OR m_type = 132 OR m_type = 130))) ORDER BY normalized_date ASC)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:158)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:114)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.content.ContentProviderProxy.bulkQueryInternal(ContentProviderNative.java:372)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.content.ContentProviderProxy.query(ContentProviderNative.java:408)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.content.ContentResolver.query(ContentResolver.java:264)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at com.uiu.messaging.Data.getContactChain(Data.java:318)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at com.uiu.messaging.ContactMessageChain.onCreate(ContactMessageChain.java:138)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
05-22 16:31:46.178: E/AndroidRuntime(1892):     at android.app.ActivityThread.performlaunchActivity(ActivityThread.java:1780)
05-22 16:31:46.178: E/AndroidRuntime(1892):     ... 11 more

android – 隐藏片段中的actionbar会抛出NullPointerException吗？

我正在尝试隐藏片段中的动作栏.要做到这一点,我正在尝试使用getActivity().getActionBar().hide();,但确实会抛出异常NullPointerException.我确实尝试过使用getSupportActionBar()但是Eclipse没有显示自动完成它只显示getActionBar();

我该怎么做 ？

分段

public class MyFragment extends Fragment {
@Override
        public void onCreate(Bundle savedInstanceState) {           
            super.onCreate(savedInstanceState); 
            getActivity().getActionBar().hide();  //nullpointerexception in this line       
        }  
}

例外：

12-05 12:19:02.415: E/AndroidRuntime(16400): FATAL EXCEPTION: main
12-05 12:19:02.415: E/AndroidRuntime(16400): java.lang.NullPointerException
12-05 12:19:02.415: E/AndroidRuntime(16400):    at br.com.mypackage.myapp.frags.BatalhaSemOponenteFrag.onCreate(BatalhaSemOponenteFrag.java:71)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.support.v4.app.Fragment.performCreate(Fragment.java:1763)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.support.v4.app.FragmentManagerImpl.movetoState(FragmentManager.java:913)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.support.v4.app.FragmentManagerImpl.movetoState(FragmentManager.java:1126)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:739)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1489)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:454)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.os.Handler.handleCallback(Handler.java:730)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.os.Handler.dispatchMessage(Handler.java:92)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.os.Looper.loop(Looper.java:176)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at android.app.ActivityThread.main(ActivityThread.java:5419)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at java.lang.reflect.Method.invokeNative(Native Method)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at java.lang.reflect.Method.invoke(Method.java:525)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
12-05 12:19:02.415: E/AndroidRuntime(16400):    at dalvik.system.NativeStart.main(Native Method)

解决方法:

由于您使用的是v4支持片段,我假设您将使用appcompat进行活动.
您必须将从getActivity()获得的活动转换为实际活动,以便将活动识别为appcompat.

试试这个：

public class MyFragment extends Fragment {
@Override
    public void onCreate(Bundle savedInstanceState) {           
        super.onCreate(savedInstanceState); 
((YourActivity)getActivity()).getSupportActionBar().hide();
    }  
}

Eclipse在Maven更新期间抛出NullPointerException

java.lang.NullPointerException
    at org.eclipse.wst.common.componentcore.internal.resources.VirtualResource.getProjectRelativePaths(VirtualResource.java:119)
    at org.eclipse.wst.common.componentcore.internal.resources.VirtualFile.getUnderlyingFiles(VirtualFile.java:104)
    at org.eclipse.wst.common.componentcore.internal.resources.VirtualFile.getUnderlyingResources(VirtualFile.java:93)
    at org.eclipse.wst.common.componentcore.internal.resources.VirtualResource.exists(VirtualResource.java:88)
    at org.eclipse.jst.common.internal.modulecore.util.ManifestUtilities.getNonBinaryComponentManifest(ManifestUtilities.java:124)
    at org.eclipse.jst.common.internal.modulecore.util.ManifestUtilities.getManifest(ManifestUtilities.java:81)
    at org.eclipse.jst.common.internal.modulecore.util.ManifestUtilities.getManifestClasspath(ManifestUtilities.java:147)
    at org.eclipse.jst.j2ee.componentcore.J2EEModuleVirtualComponent.getManifestClasspath(J2EEModuleVirtualComponent.java:248)
    at org.eclipse.jst.j2ee.componentcore.J2EEModuleVirtualComponent.calculateManifestReferences(J2EEModuleVirtualComponent.java:368)
    at org.eclipse.jst.j2ee.componentcore.J2EEModuleVirtualComponent.cacheManifestReferences(J2EEModuleVirtualComponent.java:360)
    at org.eclipse.jst.j2ee.componentcore.J2EEModuleVirtualComponent.getReferences(J2EEModuleVirtualComponent.java:176)
    at org.eclipse.jst.j2ee.componentcore.J2EEModuleVirtualComponent.getReferences(J2EEModuleVirtualComponent.java:214)
    at org.eclipse.jst.j2ee.componentcore.J2EEModuleVirtualComponent.getReferences(J2EEModuleVirtualComponent.java:207)
    at org.eclipse.m2e.wtp.WebProjectConfiguratorDelegate.configureClasspath(WebProjectConfiguratorDelegate.java:386)
    at org.eclipse.m2e.wtp.WTPProjectConfigurator.configureClasspath(WTPProjectConfigurator.java:107)
    at org.eclipse.m2e.jdt.internal.DefaultClasspathManagerDelegate.populateClasspath(DefaultClasspathManagerDelegate.java:61)
    at org.eclipse.m2e.jdt.internal.BuildPathManager.getClasspath(BuildPathManager.java:253)
    at org.eclipse.m2e.jdt.internal.BuildPathManager.getClasspath(BuildPathManager.java:363)
    at org.eclipse.m2e.jdt.internal.BuildPathManager.getClasspath(BuildPathManager.java:343)
    at org.eclipse.m2e.jdt.internal.BuildPathManager.getClasspath(BuildPathManager.java:371)
    at org.eclipse.m2e.jdt.internal.BuildPathManager.updateClasspath(BuildPathManager.java:191)
    at org.eclipse.m2e.jdt.internal.BuildPathManager.mavenProjectChanged(BuildPathManager.java:180)
    at org.eclipse.m2e.core.internal.project.registry.ProjectRegistryManager.notifyProjectChangeListeners(ProjectRegistryManager.java:746)
    at org.eclipse.m2e.core.internal.project.registry.ProjectRegistryManager.applyMutableProjectRegistry(ProjectRegistryManager.java:865)
    at org.eclipse.m2e.core.internal.project.registry.ProjectRegistryManager.refresh(ProjectRegistryManager.java:289)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration0(ProjectConfigurationManager.java:369)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$2.call(ProjectConfigurationManager.java:316)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$2.call(ProjectConfigurationManager.java:1)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:161)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:137)
    at org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:89)
    at org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1301)
    at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:313)
    at org.eclipse.m2e.core.ui.internal.UpdateMavenProjectJob.runInWorkspace(UpdateMavenProjectJob.java:77)
    at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)

我们今天的关于以编程方式抛出NullPointerException可以吗？和程序抛出异常时只能抛出自己定义的对象的分享就到这里，谢谢您的阅读，如果想了解更多关于Android gradle插件更新到3.3.0抛出NullPointerException、android – ContentResolver查询抛出nullpointerException、android – 隐藏片段中的actionbar会抛出NullPointerException吗？、Eclipse在Maven更新期间抛出NullPointerException的相关信息，可以在本站进行搜索。