java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing这样的错误，上网查了一下，一般的解决方案是，换一个低一点的版本就好了。还有人说，是缺少hamcrest的包。去官网又看了一下，结果发现这样一段话：

• junit.jar: Includes the Hamcrest classes. The simple all-in-one solution to get started quickly.Starting with version 4.11, Hamcrest is no longer included in this jar.
• junit-dep.jar: Only includes the JUnit classes but not Hamcrest. Lets you use a different Hamcrest version.

注意黑色加下划线的部分。说明4.1.1中没有hamcrest包了.

maven项目中解决方法 ，完整pom：

<!--单元测试工具 start-->
 <dependency>
 <groupId>junit</groupId>
 <artifactId>junit</artifactId>
 <version>4.11</version>
 <scope>test</scope>
 </dependency>
 <!-- https://mvnrepository.com/artifact/org.hamcrest/hamcrest-all -->
 <dependency>
 <groupId>org.hamcrest</groupId>
 <artifactId>hamcrest-all</artifactId>
 <version>1.3</version>
 <scope>test</scope>
 </dependency>
 <!--单元测试工具 end-->