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
/>

<!-- Register the bean -->
<bean />

<bean >
<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