[置顶] 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
@EnableWebSocket
public class WebSocketConfig extends WebMvcConfigurerAdapter implements
WebSocketConfigurer {
@Override
public 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
//@EnableWebSocket
public class WebSocketConfig extends WebMvcConfigurerAdapter implements
WebSocketConfigurer {
@Override
public 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;