[junit] java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger for JUnit test case for Java mail

I am using Java Mail API to read and parse emails. It is working fine with Servlet code.

Now I am trying to write a JUnit test case for the same purpose. But on line Session session = Session.getDefaultInstance(properties); I am getting the following exception:

java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger
    at javax.mail.Session.initLogger(Session.java:227)
    at javax.mail.Session.<init>(Session.java:212)
    at javax.mail.Session.getDefaultInstance(Session.java:315)
    at javax.mail.Session.getDefaultInstance(Session.java:355)
    at com.vxl.appanalytix.dataload.fromEmail.EmailParser.parseEmailSubject(EmailParser.java:44)
    at com.vxl.appanalytix.controllers.controllerClasses.GenericEmailServiceClass.readEmailAttachments(GenericEmailServiceClass.java:33)
    at com.vxl.appanalytix.dataload.GenericEmailTestCase.test(GenericEmailTestCase.java:42)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    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)
Caused by: java.lang.ClassNotFoundException: com.sun.mail.util.MailLogger
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    ... 35 more

Can anyone tell me where I am going wrong.

Really it's interesting. You need just use javax-mail.jar of "com.sun" not "javax.mail".
dwonload com.sun mail jar

Download this JAR and add it to your libraries: http://java.net/projects/javamail/downloads/download/javax.mail.jar

The javax.mail-api artifact is only good for compiling against.

You actually need to run code, so you need a complete implementation of JavaMail API. Use this:

<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>javax.mail</artifactId>
    <version>1.6.2</version>
</dependency>

NOTE: The version number will probably differ. Check the latest version here.

I use the following maven dependencies to get java mail working. The first one includes the javax.mail API (with no implementation) and the second one is the SUN implementation of the javax.mail API.

<dependency>
    <groupId>javax.mail</groupId>
    <artifactId>javax.mail-api</artifactId>
    <version>1.5.5</version>
</dependency>
<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>javax.mail</artifactId>
    <version>1.5.5</version>
</dependency>

Please see http://mvnrepository.com/artifact/javax.mail/mail/, you can download jar or use the maven dependency, depending on your project type. That should pretty much cover it and you won't get a NoClassDefFoundError exception.

It happens also if your code is expecting Java Mail 1.4 and your jars are Java Mail 1.3. Happened to me when upgraded Pentaho Kettle

Regards