在maven中使用junit执行install时报错?报错

问题：我的maven中引入了junit

<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.9</version>
			<scope>test</scope>
		</dependency>

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project shiroexample: Compilation failure: Compilation failure:
[ERROR] /E:/workspace/study/shiroexample Maven Webapp/src/main/java/com/shiro/chapter2/LoginLogoutTest.java:[3,17] 程序包org.junit不存在
[ERROR] /E:/workspace/study/shiroexample Maven Webapp/src/main/java/com/shiro/chapter2/LoginLogoutTest.java:[6,10] 找不到符号
[ERROR] 符号:   类 Test
[ERROR] 位置: 类 com.shiro.chapter2.LoginLogoutTest
[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