spring unit test start error

最近有一个项目，因为是多人一起做，加了不少的类库和配置，搞得最初建立的测试工程都启动不了，一直报一个错:

A ServletContext is required to configure default servlet handling

在网上查了，大多数人都说是肯定是spring 配置了不正确的东东，而原因有多个 ；

找了一个小时，也不知原因在哪里。

后来，发现了一篇文章说得较靠谱：

Caused by: java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling    at org.springframework.util.Assert.notNull(Assert.java:112)    at org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer.<init>(DefaultServletHandlerConfigurer.java:54)    at org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.defaultServletHandlerMapping(WebMvcConfigurationSupport.java:329)    at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration$$EnhancerByCGLIB$$bb4ceb44.CGLIB$defaultServletHandlerMapping$22(<generated>)    at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration$$EnhancerByCGLIB$$bb4ceb44$$FastClassByCGLIB$$368bb5c1.invoke(<generated>)    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:326)    at org.springframework.web.servlet.config.annotation.DelegatingWebMvcConfiguration$$EnhancerByCGLIB$$bb4ceb44.defaultServletHandlerMapping(<generated>)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:606)    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:166)    ... 43 more

出错内容和我遇到的一模一样,之后答案是这样：

One of your @Configuration classes is obviously annotated with @EnableWebMvc. That's how DelegatingWebMvcConfiguration ends up in your stack trace, since it is imported by @EnableWebMvc.So although you think you don't need a WebApplicationContext (and hence a ServletContext), you in fact do need it simply because you are loading an application context with @EnableWebMvc.You have two options:•Compose the configuration classes for your integration test so that you are not including the web-related configuration (i.e., the @Configuration class(es) annotated with @EnableWebMvc).•Annotate your test class with @WebAppConfiguration as suggested in other comments above.Regards,Sam (author of the Spring TestContext Framework

记得好象代码里哪个地方好象真的加了@EnableWebMvc

在代码查找了一下，果然发现一个同事的websocket相关的代码加了这个标志；

package com.lansheng.web.websocket;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.socket.WebSocketHandler;import org.springframework.web.socket.config.annotation.EnableWebSocket;import org.springframework.web.socket.config.annotation.WebSocketConfigurer;import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;@Configuration@EnableWebMvc@EnableWebSocketpublic class WebSocketConfig extends WebMvcConfigurerAdapter implementsWebSocketConfigurer {@Overridepublic void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {registry.addHandler(systemWebSocketHandler(),"/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor());         registry.addHandler(systemWebSocketHandler(), "/sockjs/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor())                .withSockJS();}@Bean    public WebSocketHandler systemWebSocketHandler(){        return new SystemWebSocketHandler();    }}

将声明全部注释如下

package com.lansheng.web.websocket;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.socket.WebSocketHandler;import org.springframework.web.socket.config.annotation.EnableWebSocket;import org.springframework.web.socket.config.annotation.WebSocketConfigurer;import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;//@Configuration//@EnableWebMvc//@EnableWebSocketpublic class WebSocketConfig extends WebMvcConfigurerAdapter implementsWebSocketConfigurer {@Overridepublic void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {registry.addHandler(systemWebSocketHandler(),"/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor());         registry.addHandler(systemWebSocketHandler(), "/sockjs/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor())                .withSockJS();}@Bean    public WebSocketHandler systemWebSocketHandler(){        return new SystemWebSocketHandler();    }}

然后重新启动unit test;一切正常;

总结如下：

1.当调试这样提示的时候，肯定是spring配置出了问题；

2.spring配置出了问题，并不是单是找spring-context.xml或者spring-mvc.xml，还可能包括@Configuration声明的类；

3.在unit test的时候，因为跑的是appcontext,但是因为是web application项目，有的地方用了@EnableWebMvc,而导致运行环境认为你一定需要WebApplicationContext；提示你一定要将unit test 的class要加上转换声明，作为web app来运行；这时，你有两种选择，要么，将unit test 加上@WebAppConfiguration;要么将@EnableWebMvc的声明去掉;