Junit運行報錯ClassNotFoundException的原因以及解決方案

在maven下使用junit進行單元測試報如下錯誤：

<span style="font-family:SimSun;font-size:18px;">java.lang.ClassNotFoundException: com.yc.XXXXXTest
    at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadClass(RemoteTestRunner.java:693)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.loadClasses(RemoteTestRunner.java:429)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:452)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)</span>

原因：maven生成class的目錄被改變

解決方案：

打開項目所在myeclipse的工作空間，找到.classpath文件：

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
	<classpathentry excluding="**" kind="src" output="target/classes" path="src/main/resources"/>
	<classpathentry kind="src" path="src/main/java"/>
	<classpathentry kind="src" path="src/test/resources"/>
	<classpathentry kind="src" path="src/test/java"/>
	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
		<attributes>
			<attribute name="org.eclipse.jst.component.dependency" value="/WEB-INF/lib"/>
		</attributes>
	</classpathentry>
	<classpathentry kind="output" path="src/main/webapp/WEB-INF/classes"/>
</classpath>

將output="target/test-classes"加上就好用了

<span style="font-family:SimSun;font-size:18px;"><?xml version="1.0" encoding="UTF-8"?>
<classpath>
	<classpathentry excluding="**" kind="src" output="target/classes" path="src/main/resources"/>
	<classpathentry kind="src" path="src/main/java"/>
	<classpathentry kind="src" path="src/test/resources"/>
	<classpathentry kind="src" output="target/test-classes" path="src/test/java"/>
	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER"/>
	<classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER">
		<attributes>
			<attribute name="org.eclipse.jst.component.dependency" value="/WEB-INF/lib"/>
		</attributes>
	</classpathentry>
	<classpathentry kind="output" path="src/main/webapp/WEB-INF/classes"/>
</classpath></span>