spring mvc3中异常处理

在spring mvc3中，处理异常可以这样做， 

首先定义一个自定义的异常类： 
1 public class GenericException extends RuntimeException{ 

private String customMsg; 

//getter and setter methods 

public GenericException(String customMsg) { 
this.customMsg = customMsg; 
} 

} 

2 web.xml 
  <web-app ...> 

  <error-page> 
<error-code>404</error-code> 
<location>/WEB-INF/pages/404.jsp</location> 
  </error-page> 

  <error-page> 
<exception-type>java.lang.Exception</exception-type> 
<location>/WEB-INF/pages/404.jsp</location> 
  </error-page> 

</web-app> 


3 控制器 
   CustomerController.java 

import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import org.springframework.web.servlet.ModelAndView; 
import org.springframework.web.servlet.mvc.AbstractController; 
import com.mkyong.common.exception.GenericException; 

public class CustomerController extends AbstractController{ 

@Override 
protected ModelAndView handleRequestInternal(HttpServletRequest request, 
HttpServletResponse response) throws Exception { 

throw new GenericException("Oppss...System error, please visit it later"); 

} 

} 


4 <beans xmlns="http://www.springframework.org/schema/beans" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> 

  <bean 
  class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping" /> 

<!-- Register the bean --> 
<bean class="com.mkyong.common.controller.CustomerController" /> 

<bean class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver"> 
   <property name="exceptionMappings"> 
     <props> 
<prop key="com.mkyong.common.exception.GenericException"> 
GenericExceptionPage 
</prop> 
        <prop key="java.lang.Exception">error</prop> 
     </props> 
   </property> 
</bean> 

<bean id="viewResolver" 
      class="org.springframework.web.servlet.view.InternalResourceViewResolver" > 
          <property name="prefix"> 
              <value>/WEB-INF/pages/</value> 
           </property> 
          <property name="suffix"> 
             <value>.jsp</value> 
          </property> 
    </bean> 

</beans> 

5 要注意的是，这里用了SimpleMappingExceptionResolver， 
当抛出com.mkyong.common.exception.GenericException时，会先于web.xml抛出异常，这时就去到 
/WEB-INF/pages/GenericExceptionPage.jsp这个页面处理你的自定义异常了