单元测试（三）
前言：前面讲了java的junit，这里讲一下spring+junit。转载请注明出处：https://www.cnblogs.com/yuxiaole/p/9419224.html
Spring Test介绍
当应用使用了Spring时，编写单测时需要每次手动的初始化Spring上下文，这种方式不仅繁琐，而且不能复用Spring上下文，导致单测执行时间变长，为此，Spring提供了对单测的支持，也就是Spring Test模块
Spring和JUnit的整合，提供了对应的Runner和Rule，我们平常使用的比较多的是Spring的Runner，即SpringJUnit4ClassRunner或者SpringRunner（Spring4.3），Spring的Runner会根据配置自动初始化Spring上下文，并在单测方法执行时对其进行依赖注入，避免手动的getBean操作。
Spring Test提供@ContextConfiguration来让我们指定要初始Spring上下文的配置，支持Spring的各种配置方式，如XML、JavaConfig等等方式，@ContextConfiguration和@RunWith等注解都可以注解在基类上，所以一般提供一个基类来简化单测的编写。
默认情况下，子类可以基础父类的@ContextConfiguration配置，同时可以追加自己的配置，当程序非常模块化时，可以通过指定特定的配置文件来减少初始化Bean的数量，以便提高单测的执行速度。
如何使用Spring+junit
主要目的是使用依赖注入。
可以使用注解的方式（注解加在需要测试的类上）:
@RunWith(SpringJunit4ClassRunner.class) ---->为了让测试在Spring容器环境下执行
@ContextConfiguration(locations = {"classpath:applicationContext.xml"} --->用来指明Spring的配置文件位置
@ContextConfiguration(locations = {"file:src/main/webapp/WEB-INF/spring-mvc.xml"}) --->或者这个用来指明Spring的配置文件位置
pom文件配置：
<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>4.3.14.RELEASE</version> <scope>test</scope> </dependency>
单测代码：
package com.yule.demo.service.impl; import com.yule.demo.service.DemoService; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations = {"file:src/main/webapp/WEB-INF/spring-mvc.xml"}) //@ContextConfiguration(locations={"classpath:applicationContext.xml"}) //路径在resources下面 public class DemoServiceImplTest { @Autowired private DemoService demoService; @Test public void testAssertTrue() { this.demoService.test(3); } }
遇到问题：
执行单测，控制台报错：
D:\Java\jdk1.8.0_144\bin\java -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2017.1.5\lib\idea_rt.jar=53674:D:\Program Files\JetBrains\IntelliJ IDEA 2017.1.5\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\JetBrains\IntelliJ IDEA 2017.1.5\lib\idea_rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2017.1.5\plugins\junit\lib\junit-rt.jar;D:\Java\jdk1.8.0_144\jre\lib\charsets.jar;D:\Java\jdk1.8.0_144\jre\lib\deploy.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\access-bridge-64.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\cldrdata.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\dnsns.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\jaccess.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\jfxrt.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\localedata.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\nashorn.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunec.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunjce_provider.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunmscapi.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunpkcs11.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\zipfs.jar;D:\Java\jdk1.8.0_144\jre\lib\javaws.jar;D:\Java\jdk1.8.0_144\jre\lib\jce.jar;D:\Java\jdk1.8.0_144\jre\lib\jfr.jar;D:\Java\jdk1.8.0_144\jre\lib\jfxswt.jar;D:\Java\jdk1.8.0_144\jre\lib\jsse.jar;D:\Java\jdk1.8.0_144\jre\lib\management-agent.jar;D:\Java\jdk1.8.0_144\jre\lib\plugin.jar;D:\Java\jdk1.8.0_144\jre\lib\resources.jar;D:\Java\jdk1.8.0_144\jre\lib\rt.jar;F:\IDEAworkspace\sdemo\target\test-classes;F:\IDEAworkspace\sdemo\target\classes;F:\mavenRepository\junit\junit\4.11\junit-4.11.jar;F:\mavenRepository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;F:\mavenRepository\org\springframework\spring-test\4.3.14.RELEASE\spring-test-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-context\4.3.14.RELEASE\spring-context-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-aop\4.3.14.RELEASE\spring-aop-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-expression\4.3.14.RELEASE\spring-expression-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-beans\4.3.14.RELEASE\spring-beans-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-core\4.3.14.RELEASE\spring-core-4.3.14.RELEASE.jar;F:\mavenRepository\commons-logging\commons-logging\1.2\commons-logging-1.2.jar;F:\mavenRepository\org\springframework\spring-web\4.3.14.RELEASE\spring-web-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-webmvc\4.3.14.RELEASE\spring-webmvc-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-jdbc\4.3.14.RELEASE\spring-jdbc-4.3.14.RELEASE.jar;F:\mavenRepository\org\springframework\spring-tx\4.3.14.RELEASE\spring-tx-4.3.14.RELEASE.jar;F:\mavenRepository\javax\servlet\javax.servlet-api\3.1.0\javax.servlet-api-3.1.0.jar;F:\mavenRepository\javax\servlet\jsp\jsp-api\2.2\jsp-api-2.2.jar;F:\mavenRepository\javax\servlet\jstl\1.2\jstl-1.2.jar;F:\mavenRepository\commons-fileupload\commons-fileupload\1.2.1\commons-fileupload-1.2.1.jar;F:\mavenRepository\commons-io\commons-io\2.4\commons-io-2.4.jar;F:\mavenRepository\org\slf4j\slf4j-api\1.7.25\slf4j-api-1.7.25.jar;F:\mavenRepository\org\slf4j\slf4j-log4j12\1.7.25\slf4j-log4j12-1.7.25.jar;F:\mavenRepository\log4j\log4j\1.2.17\log4j-1.2.17.jar;F:\mavenRepository\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;F:\mavenRepository\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar" com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 com.yule.demo.service.impl.DemoServiceImplTest java.lang.ExceptionInInitializerError at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:29) at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:21) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59) at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59) at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:26) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:49) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) Caused by: java.lang.IllegalStateException: SpringJUnit4ClassRunner requires JUnit 4.12 or higher. at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.<clinit>(SpringJUnit4ClassRunner.java:102) ... 14 more
找了半天才发现是版本问题，我从最后一行的报错点进去一看，代码里明确要求junit版本得是4.12或者更高。
所以解决办法就是讲 junit 版本调到4.12即可。
