Maven 3和 JUnit 4编译问题: 包 org.JUnit 不存在

How did you declare the version?

<version>4.8.2</version>

Be aware of the meaning from this declaration explained here (see NOTES):

When declaring a "normal" version such as 3.8.2 for Junit, internally this is represented as "allow anything, but prefer 3.8.2." This means that when a conflict is detected, Maven is allowed to use the conflict algorithms to choose the best version. If you specify [3.8.2], it means that only 3.8.2 will be used and nothing else.

To force using the version 4.8.2 try

<version>[4.8.2]</version>

As you do not have any other dependencies in your project there shouldn't be any conflicts that cause your problem. The first declaration should work for you if you are able to get this version from a repository. Do you inherit dependencies from a parent pom?

@Dennis Roberts: You were absolutely right: My test class was located in src/main/java. Also the value of the "scope" element in the POM for JUnit was "test", although that is how it is supposed to be. The problem was that I had been sloppy when creating the test class in Eclipse, resulting in it being created in src/main/java insted of src/test/java. This became easier to see in Eclipse's Project Explorer view after running "mvn eclipse:eclipse", but your comment was what made me see it first. Thanks.

I had a similar problem of Eclipse compiling my code just fine but Maven failed when compiling the tests every time despite the fact JUnit was in my list of dependencies and the tests were in /src/test/java/.

In my case, I had the wrong version of JUnit in my list of dependencies. I wrote JUnit4 tests (with annotations) but had JUnit 3.8.x as my dependency. Between version 3.8.x and 4 of JUnit they changed the package name from junit.framework to org.junit which is why Maven still breaks compiling using a JUnit jar.

I'm still not entirely sure why Eclipse successfully compiled. It must have its own copy of JUnit4 somewhere in the classpath. Hope this alternative solution is useful to people. I reached this solution after following Arthur's link above.

I had the same problem. All i did was - From the pom.xml file i deleted the dependency for junit 3.8 and added a new dependency for junit 4.8. Then i did maven clean and maven install. It did the trick. To verify , after maven install i went project->properties-build path->maven dependencies and saw that now the junit 3.8 jar is gone !, instead junit 4.8 jar is listed. cool!!. Now my test runs like a charm.. Hope this helps somehow..

Just to have an answer with the complete solution to help the visitors:

All you need to do is add the junit dependency to pom.xml. Don't forget the <scope>test</scope>

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>

Add this dependency to your pom.xml file:

http://mvnrepository.com/artifact/junit/junit-dep/4.8.2

<!-- https://mvnrepository.com/artifact/junit/junit-dep -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit-dep</artifactId>
<version>4.8.2</version>
</dependency>

my problem was a line inside my pom.xml i had the line <sourceDirectory>${basedir}/src</sourceDirectory> removing this line made maven use regular structure folders which solves my issue

removing the scope tag in pom.xml for junit worked..

By default , maven looks at these folders for java and test classes respectively - src/main/java and src/test/java

When the src is specified with the test classes under source and the scope for junit dependency in pom.xml is mentioned as test - org.unit will not be found by maven.

I also ran into this issue - I was trying to pull in an object from a source and it was working in the test code but not the src code. To further test, I copied a block of code from the test and dropped it into the src code, then immediately removed the JUnit lines so I just had how the test was pulling in the object. Then suddenly my code wouldn't compile.
The issue was that when I dropped the code in, Eclipse helpfully resolved all the classes so I had JUnit calls coming from my src code, which was not proper. I should have noticed the warnings at the top about unused imports, but I neglected to see them.
Once I removed the unused JUnit imports in my src file, it all worked beautifully.

I had my files at the correct places, and just removing <scope>test</scope> from the JUnit dependency entry solved the problem (I am using JUnit 4.12). I believe that with the test scope the dependency was just being ignored during the compilation phase. Now everything is working even when I call mvn test.

My case was a simple oversight.

I put the JUnit dependency declaration inside <dependencies> under the <dependencyManagement/> node instead of <project/> in the POM file. Correct way is:

<project>
<!-- Other elements -->
<dependencies>
<!-- Other dependencies-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
</dependency>
</dependencies>
<project>

I had a quite similar problem in a "test-utils" project (adding features, rules and assertions to JUnit) child of a parent project injecting dependencies. The class depending on the org.junit.rules package was in src/main/java.

So I added a dependency on junit without test scope and it solved the problem :

pom.xml of the test-util project :

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency>

pom.xml of the parent project :

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>

Me too had the same problem as shown below.

To resolve the issue, below lines are added to dependencies section in the app level build.gradle.

compile 'junit:junit:4.12'
androidTestCompile 'com.android.support.test:runner:0.5'

Gradle build then reported following warning.

Warning:Conflict with dependency 'com.android.support:support-annotations'.
Resolved versions for app (25.1.0) and test app (23.1.1) differ.
See http://g.co/androidstudio/app-test-app-conflict for details.

To solve this warning, following section is added to the app level build.gradle.

configurations.all {
resolutionStrategy {
force 'com.android.support:support-annotations:23.1.1'
}
}

Find the one solution for this error if you have code in src/main/java Utils

<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<version>3.9.1</version>
</dependency>

Changing the junit version fixed this for me. Seems like version 3.8.1 didn't work in my case. Issue fixed upon changing it to 4.12

I met this problem, this is how I soloved it:

Context:

• SpringBoot application
• Use maven to manage multiple modules
• Add junit's maven dependency in root POM's dependencyManagement(rather than dependencies, their differences can be found here)
• Intend to test class or folder inside one of the root module's child module

PS: If your situation does not match the context above, this solution may not solve your problem.

Steps

1. right click at the class or folder you want to test:
   
2. Choose More Run/Debug -> Modify Run Configuration
3. Change the module option to the one you want to test from root module