blocks|key|1068392|text|JUnit框架仅捕获运行测试的主线程中的断言错误。它不知道来自新的派生线程的异常。为了正确执行此操作，您应该将线程的终止状态传递给主线程。您应该正确地同步线程，并使用某种共享变量来指示嵌套线程的结果。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1068393|编辑：|1068394|下面是一个通用的解决方案，可以帮助您：|1068395|class+AsynchTester{
++++private+Thread+thread;
++++private+AssertionError+exc;+

++++public+AsynchTester(final+Runnable+runnable){
++++++++thread+=+new+Thread(new+Runnable(){
++++++++++++public+void+run(){
++++++++++++++++try{++++++++++++
++++++++++++++++++++runnable.run();
++++++++++++++++}catch(AssertionError+e){
++++++++++++++++++++exc+=+e;
++++++++++++++++}
++++++++++++}
++++++++});
++++}

++++public+void+start(){
++++++++thread.start();
++++}

++++public+void+test()+throws+InterruptedException{
++++++++thread.join();
++++++++if+(exc+!=+null)
++++++++++++throw+exc;
++++}
}|code-block|syntax|javascript|1068396|您应该在构造函数中将其传递给runnable，然后只需调用start()来激活，调用test()来进行验证。测试方法将在必要时等待，并将在主线程的上下文中抛出断言错误。|1068397|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|R|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

The JUnit framework captures only assertion errors in the main thread running the test. It is not aware of exceptions from within new spawn threads. 
In order to do it right, you should communicate the thread's termination state to the main thread. You should synchronize the threads correctly, and use some kind of shared variable to indicate the nested thread's outcome.

EDIT:

Here is a generic solution that can help:

<pre><code>class AsynchTester{
 private Thread thread;
 private AssertionError exc; 

 public AsynchTester(final Runnable runnable){
 thread = new Thread(new Runnable(){
 public void run(){
 try{ 
 runnable.run();
 }catch(AssertionError e){
 exc = e;
 }
 }
 });
 }

 public void start(){
 thread.start();
 }

 public void test() throws InterruptedException{
 thread.join();
 if (exc != null)
 throw exc;
 }
}
</code></pre>

You should pass it the runnable in the constructor, and then you simply call start() to activate, and test() to validate. The test method will wait if necessary, and will throw the assertion error in the main thread's context.

blocks|key|1283099|text|在涉及多个工作线程的情况下，例如在原始问题中，仅仅连接其中一个线程是不够的。理想情况下，您希望等待所有工作线程完成，同时仍然向主线程报告断言失败，例如在Eyal的回答中。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1283100|下面是一个简单的示例，说明如何使用ConcurrentUnit来实现这一点|offset|length|1283101|public+class+MyTest+extends+ConcurrentTestCase+{
++++@Test
++++public+void+testComplex()+throws+Throwable+{
++++++++int+loops+=+10;
++++++++for+(int+i+=+0;+i+<+loops;+i%2B%2B)+{
++++++++++++new+Thread(new+Runnable()+{
++++++++++++++++public+void+run()+{
++++++++++++++++++++threadAssertEquals(1,+1);
++++++++++++++++++++resume();
++++++++++++++++}
++++++++++++}).start();
++++++++}

++++++++threadWait(100,+loops);+//+Wait+for+10+resume+calls
++++}
}|code-block|syntax|javascript|1283102|entityMap|0|LINK|mutability|MUTABLE|url|http://github.com/jhalterman/concurrentunit^0|0|H|E|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@$D|U|E|V|1|W]]|A|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

Where multiple worker threads are concerned, such as in the original question, simply joining one of them is not sufficient. Ideally, you'll want to wait for all worker threads to complete while still reporting assertion failures back to the main thread, such as in Eyal's answer.

Here's a simple example of how to do this using <a href="http://github.com/jhalterman/concurrentunit" rel="noreferrer">ConcurrentUnit</a>:

<pre><code>public class MyTest extends ConcurrentTestCase {
 @Test
 public void testComplex() throws Throwable {
 int loops = 10;
 for (int i = 0; i &lt; loops; i++) {
 new Thread(new Runnable() {
 public void run() {
 threadAssertEquals(1, 1);
 resume();
 }
 }).start();
 }

 threadWait(100, loops); // Wait for 10 resume calls
 }
}
</code></pre>

blocks|key|1283163|text|我最终使用了这个模式，它同时适用于Runnables和Thread。它的灵感很大程度上来自@Eyal+Schneider的回答：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1283164|private+final+class+ThreadUnderTestWrapper+extends+ThreadUnderTest+{
++++private+Exception+ex;

++++@Override
++++public+void+run()+{
++++++++try+{
++++++++++++super.run();
++++++++}+catch+(+Exception+ex+)+{
++++++++++++this.ex+=+ex;
++++++++}
++++}

++++public+Exception+getException()+throws+InterruptedException+{
++++++++super.join();+//+use+runner.join+here+if+you+use+a+runnable.+
++++++++return+ex;
++++}
}|code-block|syntax|javascript|1283165|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I ended up using this pattern it work with both Runnables and Threads. It is largely inspired from the answer of @Eyal Schneider:

<pre><code>private final class ThreadUnderTestWrapper extends ThreadUnderTest {
 private Exception ex;

 @Override
 public void run() {
 try {
 super.run();
 } catch ( Exception ex ) {
 this.ex = ex;
 }
 }

 public Exception getException() throws InterruptedException {
 super.join(); // use runner.join here if you use a runnable. 
 return ex;
 }
}
</code></pre>

blocks|key|1068550|text|对Eyal+Schneider's+answer的一个小改进|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1068551|ExecutorService允许提交Callable，任何抛出的异常或错误都会被返回的Future重新抛出。|style|CODE|1068552|因此，测试可以写成：|1068553|@Test
public+void+test()+throws+Exception+{
++ExecutorService+es+=+Executors.newSingleThreadExecutor();
++Future<?>+future+=+es.submit(()+->+{
++++testSomethingThatMightThrowAssertionErrors();
++++return+null;
++});

++future.get();+//+This+will+rethrow+Exceptions+and+Errors+as+ExecutionException
}|code-block|syntax|javascript|1068554|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/2596530/107013|1|http://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html^0|1|N|0|0|0|F|J|8|18|6|0|F|1|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|D|3|E|5|6|7|12|8|@$A|13|B|14|F|G]|$A|15|B|16|F|G]|$A|17|B|18|F|G]]|9|@$A|19|B|1A|1|1B]]|C|$]]|$1|H|3|I|5|6|7|1C|8|@]|9|@]|C|$]]|$1|J|3|K|5|L|7|1D|8|@]|9|@]|C|$M|N]]|$1|O|3|-4|5|6|7|1E|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]|W|$5|R|S|T|C|$U|X]]]]

A small improvement to <a href="https://stackoverflow.com/a/2596530/107013">Eyal Schneider's answer</a>: 
The <a href="http://docs.oracle.com/javase/8/docs/api/java/util/concurrent/ExecutorService.html" rel="noreferrer"><code>ExecutorService</code></a> allows to submit a <code>Callable</code> and any thrown Exceptions or Errors are rethrown by the returned <code>Future</code>. 
Consequently, the test can be written as: 

<pre class="lang-java prettyprint-override"><code>@Test
public void test() throws Exception {
 ExecutorService es = Executors.newSingleThreadExecutor();
 Future&lt;?&gt; future = es.submit(() -&gt; {
 testSomethingThatMightThrowAssertionErrors();
 return null;
 });

 future.get(); // This will rethrow Exceptions and Errors as ExecutionException
}
</code></pre>

blocks|key|1283295|text|JUnit抛出扩展了Throwable的AssertionError，它具有与Exception相同的父级。您可以捕获线程的失败断言，然后保存在静态字段中，最后如果另一个线程失败了某个断言，则检查主线程。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1283296|首先，创建静态字段|1283297|private+volatile+static+Throwable+excepcionTE+=+null;|code-block|syntax|javascript|1283298|其次，将断言包装在一个try/catch和catch+AssertionError中|1283299|++++++++try
++++{
++++++assertTrue("",+mensaje.contains("1234"));
++++}
++++catch+(AssertionError+e)
++++{
++++++excepcionTE+=+e;
++++++throw+e;
++++}|1283300|最后，在主线程字段中签入|1283301|+if+(excepcionTE+!=+null)
{
++excepcionTE.printStackTrace();
++fail("Se+ha+producido+una+excepcion+en+el+servidor+TE:+"
++++++%2B+excepcionTE.getMessage());
}|1283302|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|V|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|X|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

JUnit throws AssertionError that extends of Throwable, it has the same parent of Exception. You can catch the fail assert of the thread, then save in a static field and finally check in the main thread if the other thread has failed some assert.

First, create the static field

<pre><code>private volatile static Throwable excepcionTE = null;
</code></pre>

Second, wrap the asserts in a try/catch and catch AssertionError

<pre><code> try
 {
 assertTrue("", mensaje.contains("1234"));
 }
 catch (AssertionError e)
 {
 excepcionTE = e;
 throw e;
 }
</code></pre>

And finally, check in the main thread that field

<pre><code> if (excepcionTE != null)
{
 excepcionTE.printStackTrace();
 fail("Se ha producido una excepcion en el servidor TE: "
 + excepcionTE.getMessage());
}
</code></pre>

What am I doing wrong that an exception is thrown instead of showing a failure, or should I not have assertions inside threads?

<pre><code> @Test
 public void testComplex() throws InterruptedException {
 int loops = 10;
 for (int i = 0; i &lt; loops; i++) {
 final int j = i;
 new Thread() {
 @Override
 public void run() {
 ApiProxy.setEnvironmentForCurrentThread(env);//ignore this
 new CounterFactory().getCounter("test").increment();//ignore this too
 int count2 = new CounterFactory().getCounter("test").getCount();//ignore
 assertEquals(j, count2);//here be exceptions thrown. this is line 75
 }
 }.start();
 }
 Thread.sleep(5 * 1000);
 assertEquals(loops, new CounterFactory().getCounter("test").getCount());
}
</code></pre>

StackTrace

<pre><code>Exception in thread "Thread-26" junit.framework.AssertionFailedError: expected:&lt;5&gt; but was:&lt;6&gt;
 at junit.framework.Assert.fail(Assert.java:47)
 at junit.framework.Assert.failNotEquals(Assert.java:277)
 at junit.framework.Assert.assertEquals(Assert.java:64)
 at junit.framework.Assert.assertEquals(Assert.java:195)
 at junit.framework.Assert.assertEquals(Assert.java:201)
 at com.bitdual.server.dao.ShardedCounterTest$3.run(ShardedCounterTest.java:77)
</code></pre>

junit assert in thread throws exception

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

抛出异常而不是显示失败，或者我不应该在线程中有断言，这是我做错了什么？ @Test public void testComplex() throws InterruptedException { int loops = 10; for (int i = 0; i < loops; i++) { final in...

问线程抛出异常中的junit断言
EN

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问线程抛出异常中的junit断言EN

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问线程抛出异常中的junit断言
EN