Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:testCompile

1. 好坑呐，一个问题解决了好久才解决。终于可以了不容易啊。

跟着《Maven实战》学习第一个项目就出问题。Compile通过了，可是Test时有问题。网上报这个错的大部分用的都是Eclipse的。我用的Intellij IDEA。搞得好累。

（1）书上的配置时这样的：

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>

结果报这个错误：
[WARNING] Some problems were encountered while building the effective model for com.jasminezhao.mvntest:hello-world:jar:1.0-SNAPSHOT
[WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-compiler-plugin is missing. @ line 20, column 21
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.

需要加上：<version>3.1</version>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.5</source>
<target>1.5</target>
</configuration>
</plugin>(2) 报下面的错误，

[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[3,17] package org.junit does not exist
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[5,24] package org.junit does not exist
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[5,1] static import only from classes and interfaces
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[11,6] cannot find symbol
symbol:   class Test
location: class HelloWorldTest
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[17,9] cannot find symbol
symbol:   method assertEquals(java.lang.String,java.lang.String)
location: class HelloWorldTest
[INFO] 5 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 9.056 s
[INFO] Finished at: 2014-12-11T17:50:50+08:00
[INFO] Final Memory: 11M/27M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:testCompile (default-testCompile) on project hello-world: Compilation failure: Compilation failure:
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[3,17] package org.junit does not exist
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[5,24] package org.junit does not exist
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[5,1] static import only from classes and interfaces
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[11,6] cannot find symbol
[ERROR] symbol:   class Test
[ERROR] location: class HelloWorldTest
[ERROR] /D:/Maven Hello World Project/src/test/java/HelloWorldTest.java:[17,9] cannot find symbol
[ERROR] symbol:   method assertEquals(java.lang.String,java.lang.String)
[ERROR] location: class HelloWorldTest
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException[/code]发现External Libraries里面有junit 4.1.0 jar，但是发现项目还是哪里有一个junit 3.8.1 jar，我估计两个jar冲突了。把两个都删了，打算重新导入。结果在项目里点击下面的按钮都不能导入，后面把.m2（C:\Users\*\.m2\repository\junit\junit）下面的包删除了。在点击旁边的一个Event Log里面蓝色字体提示的也会帮助导入包。一直不知道怎么导入maven的jar包。
截图如下：