记一次SpringMVC进行MockMVC单元测试各种报错的情况及解决方法

清疚 2023-07-13 03:28 37阅读 0赞

接手一个项目，在使用SpringMVC的mockMVC测试POST请求，编写单元测试用例时，遇到了以下报错

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.xmh.test.SpringTest': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.context.WebApplicationContext com.xmh.test.SpringTest.wac; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.context.WebApplicationContext] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: { @org.springframework.beans.factory.annotation.Autowired(required=true)}
    	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214)
    	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:385)
    	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118)
    	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
    	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:228)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:217)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:276)
    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:278)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:236)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180)
    	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
    	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
    Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private org.springframework.web.context.WebApplicationContext com.xmh.test.SpringTest.wac; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.context.WebApplicationContext] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: { @org.springframework.beans.factory.annotation.Autowired(required=true)}
    	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:571)
    	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
    	... 26 more
    Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [org.springframework.web.context.WebApplicationContext] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: { @org.springframework.beans.factory.annotation.Autowired(required=true)}
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1326)
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1072)
    	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:967)
    	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:543)
    	... 28 more

意思是没有办法注入WebApplicationContext，这在之前都是自动注入的，怎么就不能注入了呢？看了一下测试类注解，是这样的

@RunWith(SpringJUnit4ClassRunner.class)
    
    @ContextConfiguration(locations = {  "classpath:application.xml"})

这个好像只导入了Spring的配置文件，想到应该是缺少了SpringMVC的配置信息,于是加上，加上之后

@RunWith(SpringJUnit4ClassRunner.class)
    
    @ContextConfiguration(locations = {  "classpath:application.xml", "classpath:springmvc/spring-mvc.xml" })

运行试试看，还是一样的报错，没有解决！  
于是在网上找答案，有文章说是要加上 **@WebAppConfiguration** 注解，加上之后变成这样

@RunWith(SpringJUnit4ClassRunner.class)
    @WebAppConfiguration
    @ContextConfiguration(locations = {  "classpath:application.xml", "classpath:springmvc/spring-mvc.xml" })

继续开开心心运行，然而…

java.lang.ExceptionInInitializerError
    	at org.springframework.mock.web.MockHttpServletResponse.<init>(MockHttpServletResponse.java:86)
    	at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:201)
    	at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:123)
    	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:228)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:217)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:276)
    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:278)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:236)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180)
    	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:89)
    	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
    	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)
    Caused by: java.util.MissingResourceException: Can't find bundle for base name javax.servlet.LocalStrings, locale zh_CN
    	at java.util.ResourceBundle.throwMissingResourceException(Unknown Source)
    	at java.util.ResourceBundle.getBundleImpl(Unknown Source)
    	at java.util.ResourceBundle.getBundle(Unknown Source)
    	at javax.servlet.ServletOutputStream.<clinit>(ServletOutputStream.java:87)
    	... 25 more

快哭了好吧，这什么鬼？？连报错信息都不显示代码行数！我太难了！  
先找第一句的报错`java.lang.ExceptionInInitializerError`，网上很多说是静态变量初始化就被调用造成了，于是我就把所有component中的static变量都变成了私有变量，但是！并没有什么用啊！  
于是找第二句报错`Caused by: java.util.MissingResourceException: Can't find bundle for base name javax.servlet.LocalStrings, locale zh_CN`，网上说法如下：

> 这个问题的原因是MessageResource\_zh\_CN.properties，这个配置文件没有放在classpath中，我们可以在我们需要加载该配置文件的地方

有点莫名其妙，我根本根本就没有这个配置文件啊。难道又不是这个问题，于是我就单独对Controller进行测试，发现加了`@WebAppConfiguration`注解时Controller是可以被注入的，不加就不行？难道是不能加？于是就先不加，在网上找了获取WebApplicationContext的方法，比如

WebApplicationContext wac = ContextLoader.getCurrentWebApplicationContext();

但是打印出来却是null.  
既然这个是null，controller是有值的，就用注入的controller获得MockMvc对象好了，结果是打印出来Controller对象了，但是报错仍然是`java.lang.ExceptionInInitializerError`。  
到底哪里错了呢，把配置文件看了一遍，好像没什么错，而且既然controller已经注入了，说明Spring环境应该是没问题的。又用浏览器请求Controller发现也是好用的，所以问题就在测试用例的类上了。  
再回过头看，问题也就是上面两个，第一个问题说注入不了，第二个说配置问题。注入Controller加上Controller对象可用，所以第一个问题很可能是第二个造成的。第二个里面的静态变量已经被我“消灭”了，所以最有可能的加上下面一个报错，也就是这一句

Caused by: java.util.MissingResourceException: Can't find bundle for base name javax.servlet.LocalStrings, locale zh_CN

找到一个说缺少javax.servlet-api的jar包可能导致这个问题，搜了一下POM文件，果然没有这个依赖。加上试了一下，不是不知道，一试吓一跳，使用如下方法可以获取MockMvc对象了。

mockMvc = MockMvcBuilders.standaloneSetup(addController).build();

于是，又试了一下

@Autowired
    	private WebApplicationContext wac;

又出现了最初的那个异常信息，真叫人头大。看`@WebAppConfiguration`被注释掉了，就解注释看看，解注释之后如下

@RunWith(SpringJUnit4ClassRunner.class)
    @WebAppConfiguration
    @ContextConfiguration(locations = {  "classpath:application.xml", "classpath:springmvc/spring-mvc.xml" })

这次果然成功了！

所以，最终的解决方法就是：

1.  在POM文件中加入如下依赖：

<dependency>
       		<groupId>javax.servlet</groupId>
       		<artifactId>javax.servlet-api</artifactId>
       		<version>4.0.1</version>
       		<scope>provided</scope>
       	</dependency>

1.  加上`@WebAppConfiguration`注解
2.  确认导入了SpringMVC的配置信息