标签：tomcat configuration spring java

我在这里找到了一个100％基于代码的spring配置示例：

http://docs.spring.io/spring/docs/3.1.x/javadoc-api/org/springframework/web/WebApplicationInitializer.html

内容：

public class MyWebAppInitializer implements WebApplicationInitializer {

@Override
public void onStartup(ServletContext container) {
  // Create the 'root' Spring application context
  AnnotationConfigWebApplicationContext rootContext =
    new AnnotationConfigWebApplicationContext();
  rootContext.register(AppConfig.class);

  // Manage the lifecycle of the root application context
  container.addListener(new ContextLoaderListener(rootContext));

  // Create the dispatcher servlet's Spring application context
  AnnotationConfigWebApplicationContext dispatcherContext =
    new AnnotationConfigWebApplicationContext();
  dispatcherContext.register(DispatcherConfig.class);

  // Register and map the dispatcher servlet
  ServletRegistration.Dynamic dispatcher =
    container.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));
  dispatcher.setLoadOnStartup(1);
  dispatcher.addMapping("/");
}

}

在上面的示例中,他们从未注册配置类后调用过refresh().
但是API表示-必须调用refresh()才能使上下文完全处理新类.
所以我在每个注册语句之前添加了refresh()

rootContext.register(AppConfig.class);
rootContext.refresh();

dispatcherContext.register(DispatcherConfig.class);
dispatcherContext.refresh();

结果是：

SEVERE: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component    [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:702)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:699)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1647)
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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:465)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:415)
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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1487)
at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:97)
at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1328)
at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1420)
at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:848)
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 sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:322)
at sun.rmi.transport.Transport$1.run(Transport.java:177)
at sun.rmi.transport.Transport$1.run(Transport.java:174)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:173)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:556)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:811)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:670)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:724)
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultServletHandlerMapping' defined in class path resource [org/springframework/web/servlet/config/annotation/DelegatingWebMvcConfiguration.class]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Factory method [public org.springframework.web.servlet.HandlerMapping org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport.defaultServletHandlerMapping()] threw exception; nested exception is java.lang.IllegalArgumentException: A ServletContext is required to configure default servlet handling
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:592)

但是,如果我删除了refresh()(显然),就可以正常工作(我使用的是Tomcat 8.0)
最后,我不完全了解是否必须在这样的代码中使用refresh().如果没有-我什么时候应该使用它？

解决方法:

在您的情况下,这仅对传递给DispatcherServlet的ApplicationContext重要.该DispatcherServlet构造函数指出

The given web application context may or may not yet be refreshed. If
it has not already been refreshed (the recommended approach), then the
following will occur:

• If the given context does not already have a parent, the root application context will be set as the parent.
• If the given context has not already been assigned an id, one will be assigned to it
• ServletContext and ServletConfig objects will be delegated to the application context
• postProcessWebApplicationContext will be called
• Any ApplicationContextInitializers specified through
  the “contextInitializerClasses” init-param or through the
  setContextInitializers property will be applied.
• refresh() will be called if the context implements ConfigurableApplicationContext

If the context has already been refreshed, none of the above will
occur, under the assumption that the user has performed these actions
(or not) per their specific needs.

因此,对于DispatcherServlet,您必须执行以下操作

AnnotationConfigWebApplicationContext dispatcherContext = new AnnotationConfigWebApplicationContext();
dispatcherContext.register(DispatcherConfig.class);

// will take care of calling refresh() on the ApplicationContext
ServletRegistration.Dynamic dispatcher = container.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));

这对于DispatcherServlet配置是必需的,因为由于@EnableWebMvc(或等效的< mvc：annotation-driven>)而生成的某些Bean需要Servlet容器提供的ServletContext和/或ServletConfig对象.

根上下文不应具有此类依赖性,因此可以安全地执行此操作

AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
rootContext.register(AppConfig.class);
rootContext.refresh();

请注意,您可以通过将@Configuration类作为参数传递给其构造函数来创建AnnotationConfigWebApplicationContext对象.

标签：tomcat,configuration,spring,java
来源： https://codeday.me/bug/20191029/1963998.html

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