blocks|key|158612|text|这样试试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|158613|@Rule+public+ExpectedException+thrown+=+ExpectedException.none();

@Test+public+void+testMethod()+throws+Throwable+{
++++final+String+error+=+"error+message";
++++Throwable+expectedCause+=+new+IllegalStateException(error);
++++thrown.expectCause(IsEqual.equalTo(expectedCause));
++++throw+new+RuntimeException(expectedCause);
}|code-block|syntax|javascript|158614|如有必要，请考虑不要通过等于而是通过IsInstanceOf和/或比较异常消息来检查原因。通过相等比较原因也会检查堆栈跟踪，这可能比您想要测试/检查的更多。例如，如下所示：|158615|@Rule+public+ExpectedException+thrown+=+ExpectedException.none();

@Test+public+void+testMethod()+throws+Throwable+{
++++final+String+error+=+"error+message";
++++thrown.expectCause(IsInstanceOf.<Throwable>instanceOf(IllegalStateException.class));
++++thrown.expectMessage(error);
++++throw+new+RuntimeException(new+IllegalStateException(error));
}|158616|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Try it this way:

<pre><code>@Rule public ExpectedException thrown = ExpectedException.none();

@Test public void testMethod() throws Throwable {
 final String error = "error message";
 Throwable expectedCause = new IllegalStateException(error);
 thrown.expectCause(IsEqual.equalTo(expectedCause));
 throw new RuntimeException(expectedCause);
}
</code></pre>

Consider not to check against the cause by equals but by IsInstanceOf and / or comapring the exception message if necessary. Comparing the cause by equals check the stacktrace as well, which may be more than you would like to test / check. Like this for example:

<pre><code>@Rule public ExpectedException thrown = ExpectedException.none();

@Test public void testMethod() throws Throwable {
 final String error = "error message";
 thrown.expectCause(IsInstanceOf.&lt;Throwable&gt;instanceOf(IllegalStateException.class));
 thrown.expectMessage(error);
 throw new RuntimeException(new IllegalStateException(error));
}
</code></pre>

blocks|key|2964003|text|这是JUnit版本的问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2964004|ExpectedException.expectCause()是从4.11开始的。|offset|length|style|CODE|2964005|在4.10或更低版本中没有这样的方法。|2964006|您应该确保您的运行时JUnit版本为>=+4.11，与您的编译版本相同。|2964007|entityMap|0|LINK|mutability|MUTABLE|url|http://junit.org/junit4/javadoc/4.11/org/junit/rules/ExpectedException.html|1|http://junit.org/junit4/javadoc/4.10/org/junit/rules/ExpectedException.html^0|0|0|V|X|4|0|0|1|4|1|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|W|8|@$D|X|E|Y|F|G]]|9|@$D|Z|E|10|1|11]]|A|$]]|$1|H|3|I|5|6|7|12|8|@]|9|@$D|13|E|14|1|15]]|A|$]]|$1|J|3|K|5|6|7|16|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|S]]|T|$5|O|P|Q|A|$R|U]]]]

It's JUnit version problem.

<code>ExpectedException.expectCause()</code> is since <a href="http://junit.org/junit4/javadoc/4.11/org/junit/rules/ExpectedException.html" rel="nofollow">4.11</a>.

No such method in <a href="http://junit.org/junit4/javadoc/4.10/org/junit/rules/ExpectedException.html" rel="nofollow">4.10</a> or lower. 

You should ensure your runtime JUnit version >= 4.11, same as your compile version.

blocks|key|158689|text|您可以使用此处描述的自定义匹配器(http://www.javacodegeeks.com/2014/03/junit-expectedexception-rule-beyond-basics.html)来测试异常的原因。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|158690|自定义匹配器|158691|private+static+class+CauseMatcher+extends+TypeSafeMatcher<Throwable>+{

++++private+final+Class<?+extends+Throwable>+type;
++++private+final+String+expectedMessage;

++++public+CauseMatcher(Class<?+extends+Throwable>+type,+String+expectedMessage)+{
++++++++this.type+=+type;
++++++++this.expectedMessage+=+expectedMessage;
++++}

++++@Override
++++protected+boolean+matchesSafely(Throwable+item)+{
++++++++return+item.getClass().isAssignableFrom(type)
++++++++++++++++&&+item.getMessage().contains(expectedMessage);
++++}

++++@Override
++++public+void+describeTo(Description+description)+{
++++++++description.appendText("expects+type+")
++++++++++++++++.appendValue(type)
++++++++++++++++.appendText("+and+a+message+")
++++++++++++++++.appendValue(expectedMessage);
++++}
}|code-block|syntax|javascript|158692|测试用例|158693|@Rule
public+ExpectedException+thrown+=+ExpectedException.none();

@Test
public+void+verifiesCauseTypeAndAMessage()+{
++++thrown.expect(RuntimeException.class);
++++thrown.expectCause(new+CauseMatcher(IllegalStateException.class,+"Illegal+state"));

++++throw+new+RuntimeException("Runtime+exception+occurred",
++++++++++++new+IllegalStateException("Illegal+state"));
}|158694|entityMap|0|LINK|mutability|MUTABLE|url|http://www.javacodegeeks.com/2014/03/junit-expectedexception-rule-beyond-basics.html^0|H|2C|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|6|7|10|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|11|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|C|$]]|$1|M|3|N|5|H|7|13|8|@]|9|@]|C|$I|J]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

You can use a custom matcher as described here (<a href="http://www.javacodegeeks.com/2014/03/junit-expectedexception-rule-beyond-basics.html" rel="noreferrer">http://www.javacodegeeks.com/2014/03/junit-expectedexception-rule-beyond-basics.html</a>) to test for the cause of an exception.

<h2>Custom matcher</h2>

<pre><code>private static class CauseMatcher extends TypeSafeMatcher&lt;Throwable&gt; {

 private final Class&lt;? extends Throwable&gt; type;
 private final String expectedMessage;

 public CauseMatcher(Class&lt;? extends Throwable&gt; type, String expectedMessage) {
 this.type = type;
 this.expectedMessage = expectedMessage;
 }

 @Override
 protected boolean matchesSafely(Throwable item) {
 return item.getClass().isAssignableFrom(type)
 &amp;&amp; item.getMessage().contains(expectedMessage);
 }

 @Override
 public void describeTo(Description description) {
 description.appendText("expects type ")
 .appendValue(type)
 .appendText(" and a message ")
 .appendValue(expectedMessage);
 }
}
</code></pre>

<h2>Test case</h2>

<pre><code>@Rule
public ExpectedException thrown = ExpectedException.none();

@Test
public void verifiesCauseTypeAndAMessage() {
 thrown.expect(RuntimeException.class);
 thrown.expectCause(new CauseMatcher(IllegalStateException.class, "Illegal state"));

 throw new RuntimeException("Runtime exception occurred",
 new IllegalStateException("Illegal state"));
}
</code></pre>

blocks|key|158698|text|简单介绍一下静态导入，同时检查类和原因异常的消息：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|158699|import+static+org.hamcrest.Matchers.allOf;
import+static+org.hamcrest.Matchers.hasProperty;
import+static+org.hamcrest.Matchers.instanceOf;
import+static+org.hamcrest.Matchers.is;
import+static+org.junit.Assert.assertThat;

@Test
public+void+testThatThrowsNiceExceptionWithCauseAndMessages(){

+++++expectedException.expect(RuntimeException.class+);
+++++expectedException.expectMessage("Exception+message");+++++++++++++++++++++++++++++++++++++++++++
+++++expectedException.expectCause(allOf(instanceOf(IllegalStateException.class),
++++++++++++++++++++++++++++++++++++++++hasProperty("message",+is("Cause+message")))+);

+++++throw+new+RuntimeException("Exception+message",+new+IllegalStateException("Cause+message"));
}|code-block|syntax|javascript|158700|您甚至可以使用hasProperty匹配器来断言嵌套的原因或测试"getLocalizedMessage“方法。|158701|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

A little bit more briefly with static imports and checking both the class and the message of the cause exception: 

<pre><code>import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.Matchers.hasProperty;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

@Test
public void testThatThrowsNiceExceptionWithCauseAndMessages(){

 expectedException.expect(RuntimeException.class );
 expectedException.expectMessage("Exception message"); 
 expectedException.expectCause(allOf(instanceOf(IllegalStateException.class),
 hasProperty("message", is("Cause message"))) );

 throw new RuntimeException("Exception message", new IllegalStateException("Cause message"));
}
</code></pre>

You could even use the hasProperty matcher to assert nested causes or to test the "getLocalizedMessage" method.

blocks|key|161143|text|来自hamcrest的any(Class)+matcher工作得很好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|161144|@Rule
public+ExpectedException+thrown+=+ExpectedException.none();
...
@Test
public+void+testMethod()
{
++++thrown.expect(RuntimeException.class);
++++thrown.expectCause(org.hamcrest.Matchers.any(IllegalStateException.class));
}|code-block|syntax|javascript|161145|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|$]]

The any(Class&lt;T&gt;) matcher from hamcrest works nicely:

<pre><code>@Rule
public ExpectedException thrown = ExpectedException.none();
...
@Test
public void testMethod()
{
 thrown.expect(RuntimeException.class);
 thrown.expectCause(org.hamcrest.Matchers.any(IllegalStateException.class));
}
</code></pre>

blocks|key|2964090|text|通常我更喜欢下面的结构：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2964091|expectedException.expectCause(isA(NullPointerException.class));|offset|length|style|CODE|2964092|entityMap^0|0|0|1R|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

Normally I like more the following construction:

<code>expectedException.expectCause(isA(NullPointerException.class));
</code>

blocks|key|2751581|text|导入|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2751582|<dependency>
++<groupId>it.ozimov</groupId>
++<artifactId>java7-hamcrest-matchers</artifactId>
++<version>1.3.0</version>
++<scope>test</scope>
</dependency>|code-block|syntax|javascript|2751583|然后：|2751584|@Rule
public+ExpectedException+thrown+=+ExpectedException.none();
...
@Test
public+void+testMethod()
{
++++final+String+errorMessage+=+"error+message";
++++Class<?+extends+Throwable>+expectedCause+=+IllegalStateException.class;
++++thrown.expectCause(ExpectedException.exceptionWithMessage(expectedCause,+errorMessage));
++++someServiceThatTrowsException.foo();
}|2751585|它也适用于原因的子类型。在其他解决方案中，我观察到它们接受超类型，这在我看来是错误的。|2751586|消息必须等于或包含在原因的错误消息中。|2751587|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Import

<pre><code>&lt;dependency&gt;
 &lt;groupId&gt;it.ozimov&lt;/groupId&gt;
 &lt;artifactId&gt;java7-hamcrest-matchers&lt;/artifactId&gt;
 &lt;version&gt;1.3.0&lt;/version&gt;
 &lt;scope&gt;test&lt;/scope&gt;
&lt;/dependency&gt;
</code></pre>

And then:

<pre><code>@Rule
public ExpectedException thrown = ExpectedException.none();
...
@Test
public void testMethod()
{
 final String errorMessage = "error message";
 Class&lt;? extends Throwable&gt; expectedCause = IllegalStateException.class;
 thrown.expectCause(ExpectedException.exceptionWithMessage(expectedCause, errorMessage));
 someServiceThatTrowsException.foo();
}
</code></pre>

It works also with subtype of the cause. In other solutions I observed that they accept a supertype, that is wrong in my opinion.

Message must be equal or contained in the cause's error message.

blocks|key|158763|text|总而言之。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|158764|使用JUnit+4(+hamcrest+1.3，请注意，JUnit+4依赖于hamcrest-core，其中不包括org.hamcrest.beans包)|158765|因此，您需要导入：|158766|<dependency>
++<groupId>org.hamcrest</groupId>
++<artifactId>hamcrest-all</artifactId>
++<version>1.3</version>
++<scope>test</scope>
</dependency>|code-block|syntax|javascript|158767|代码：|158768|import+static+org.hamcrest.CoreMatchers.*;
import+static+org.hamcrest.beans.HasPropertyWithValue.hasProperty;

@Rule
public+ExpectedException+expectedException+=+ExpectedException.none();

@Test
public+void+testThatThrowsNiceExceptionWithCauseAndMessages(){

++expectedException.expect(RuntimeException.class+);
++expectedException.expectMessage("Exception+message");+++++++++++++++++++++++++++++++++++++++++++
++expectedException.expectCause(
++++allOf(
++++++isA(IllegalStateException.class),
++++++hasProperty("message",+is("Cause+message"))
++++)
++);

++throw+
++++new+RuntimeException("Exception+message",+
++++++new+IllegalStateException("Cause+message"));
}|158769|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|T|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|V|8|@]|9|@]|A|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

To summarize all.

With JUnit 4 ( hamcrest 1.3 , and be careful, JUnit 4 depend on hamcrest-core which not include org.hamcrest.beans package)

So, you need to import:

<pre class="lang-xml prettyprint-override"><code>&lt;dependency&gt;
 &lt;groupId&gt;org.hamcrest&lt;/groupId&gt;
 &lt;artifactId&gt;hamcrest-all&lt;/artifactId&gt;
 &lt;version&gt;1.3&lt;/version&gt;
 &lt;scope&gt;test&lt;/scope&gt;
&lt;/dependency&gt;
</code></pre>

Code:

<pre class="lang-java prettyprint-override"><code>import static org.hamcrest.CoreMatchers.*;
import static org.hamcrest.beans.HasPropertyWithValue.hasProperty;

@Rule
public ExpectedException expectedException = ExpectedException.none();

@Test
public void testThatThrowsNiceExceptionWithCauseAndMessages(){

 expectedException.expect(RuntimeException.class );
 expectedException.expectMessage("Exception message"); 
 expectedException.expectCause(
 allOf(
 isA(IllegalStateException.class),
 hasProperty("message", is("Cause message"))
 )
 );

 throw 
 new RuntimeException("Exception message", 
 new IllegalStateException("Cause message"));
}
</code></pre>

blocks|key|159889|text|您完全可以使用内置的匹配器org.hamcrest.Matchers.instanceOf和org.junit.internal.matchers.ThrowableMessageMatcher.hasMessage来完成这项工作|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|159890|import+org.junit.Rule;
import+org.junit.Test;
import+org.junit.rules.ExpectedException;

import+static+org.hamcrest.Matchers.equalTo;
import+static+org.hamcrest.Matchers.instanceOf;
import+static+org.hamcrest.Matchers.both;
import+static+org.junit.internal.matchers.ThrowableMessageMatcher.hasMessage;

public+class+temp+{
++++@Rule
++++public+ExpectedException+expectedException+=+ExpectedException.none();

++++@Test
++++public+void+youCannotDivideByZero()+{
++++++++expectedException.expect(RuntimeException.class);
++++++++expectedException.expectMessage(equalTo("Division+exception"));
++++++++expectedException.expectCause(both(hasMessage(equalTo("/+by+zero"))).and(instanceOf(ArithmeticException.class)));
++++++++divide(1,+0);
++++}

++++private+float+divide(int+first,+int+second)+{
++++++++try+{
++++++++++++return+first+/+second;
++++++++}+catch(ArithmeticException+e)+{
++++++++++++throw+new+RuntimeException("Division+exception",+e);
++++++++}
++++}
}|code-block|syntax|javascript|159891|entityMap^0|D|W|1A|1Q|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

You can do this entirely with built-in matchers <code>org.hamcrest.Matchers.instanceOf</code> and <code>org.junit.internal.matchers.ThrowableMessageMatcher.hasMessage</code>:

<pre><code>import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.both;
import static org.junit.internal.matchers.ThrowableMessageMatcher.hasMessage;

public class temp {
 @Rule
 public ExpectedException expectedException = ExpectedException.none();

 @Test
 public void youCannotDivideByZero() {
 expectedException.expect(RuntimeException.class);
 expectedException.expectMessage(equalTo("Division exception"));
 expectedException.expectCause(both(hasMessage(equalTo("/ by zero"))).and(instanceOf(ArithmeticException.class)));
 divide(1, 0);
 }

 private float divide(int first, int second) {
 try {
 return first / second;
 } catch(ArithmeticException e) {
 throw new RuntimeException("Division exception", e);
 }
 }
}
</code></pre>

blocks|key|2964196|text|验证Kotlin语言抛出异常的消息和原因示例：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2964197|@get:Rule
val+exceptionRule:+ExpectedException+=+ExpectedException.none()

@Test
fun+`test+method`()+{
++++exceptionRule.expect(NestedServletException::class.java)
++++exceptionRule.expectMessage("error+msg")
++++exceptionRule.expectCause(instanceOf(IllegalStateException::class.java))
++++//+...|code-block|syntax|javascript|2964198|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|$]]

Example of verifying the message and cause of a thrown exception for Kotlin language:

<pre><code>@get:Rule
val exceptionRule: ExpectedException = ExpectedException.none()

@Test
fun `test method`() {
 exceptionRule.expect(NestedServletException::class.java)
 exceptionRule.expectMessage("error msg")
 exceptionRule.expectCause(instanceOf(IllegalStateException::class.java))
 // ...
</code></pre>

I have a test:

<pre><code>@Rule
public ExpectedException thrown = ExpectedException.none();
...
@Test
public void testMethod()
{
 final String error = "error message";
 Throwable expectedCause = new IllegalStateException(error);
 thrown.expectCause(org.hamcrest.Matchers.&lt;Throwable&gt;equalTo(expectedCause));
 someServiceThatTrowsException.foo();
}
</code></pre>

When run via mvn the test method, I'm getting the error:

<blockquote>
 java.lang.NoSuchMethodError:
 org.junit.rules.ExpectedException.expectCause(Lorg/hamcrest/Matcher;)V
</blockquote>

Test compiles fine.

Please help me, cannot understand how to test the cause of the exception?

Using junit @Rule, expectCause() and hamcrest matchers

Kotlin

我有个测试：@Rulepublic ExpectedException thrown = ExpectedException.none();...@Testpublic void testMethod(){    final String error = "error message";    Throwable ex...

问使用junit @Rule、expectCause()和hamcrest匹配器
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