struts2异常处理，global-results定义全局结果处理

2023-01-29 12:21:55

<global-results>定义全局结果处理

一般发生异常之后 结果返回errHandler

因为errHandler是由<global-exception-mappings>关联到Exception这个类了
然后处理结果

 <result name="errHandler" type="chain">

然后它就根据

<param name="actionName">errorProcessor</param>

找action

<action name="errorProcessor" class="cn.itcast.sh.error.ErrorProcess">

             <result>/error.jsp</result>

  </action>
处理了 然后 返回到 error.jsp

在struts.xml中

 <?xml version="1.0" encoding="utf-8"?>

    <!DOCTYPE struts PUBLIC

     "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

     "http://struts.apache.org/dtds/struts-2.3.dtd">

 <struts>

     <constant name="struts.devMode" value="true" />

     <constant name="struts.enable.DynamicMethodInvocation" value="false"></constant>

     <!-- <constant name="struts.custom.i18n.resources" value="itcast"></constant> -->

     <package name="struts-global" namespace="/" extends="struts-default">

         <global-results>

             <result name="errHandler" type="chain">

                 <param name="actionName">errorProcessor</param>

             </result>

         </global-results>

         <global-exception-mappings>

             <exception-mapping result="errHandler" exception="java.lang.Exception">

             </exception-mapping>

         </global-exception-mappings>

         <action name="errorProcessor" class="cn.itcast.sh.error.ErrorProcess">

             <result>/error.jsp</result>

         </action>

     </package>

然后其他包都继承它就默认使用了其中定义的错误处理

然后实现类

class="cn.itcast.sh.error.ErrorProcess"

 package cn.itcast.sh.error;

 import com.opensymphony.xwork2.ActionContext;

 import com.opensymphony.xwork2.ActionSupport;

 public class ErrorProcess extends ActionSupport {

     private Exception exception;

     public Exception getException() {

         return exception;

     }

     public void setException(Exception exception) {

         this.exception = exception;

     }

     @Override

     public String execute()

     {

         ActionContext.getContext().getValueStack().push(this.exception.getMessage());　　　　　　//放到值栈顶

         return this.SUCCESS;

     }

 }

例子

struts.xml配置

 <?xml version="1.0" encoding="utf-8"?>

    <!DOCTYPE struts PUBLIC

     "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

     "http://struts.apache.org/dtds/struts-2.3.dtd">

 <struts>

     <constant name="struts.devMode" value="true" />

     <constant name="struts.enable.DynamicMethodInvocation" value="false"></constant>

     <!-- <constant name="struts.custom.i18n.resources" value="itcast"></constant> -->

     <package name="struts-global" namespace="/" extends="struts-default">

         <global-results>

             <result name="errHandler" type="chain">

                 <param name="actionName">errorProcessor</param>

             </result>

         </global-results>

         <global-exception-mappings>

             <exception-mapping result="errHandler" exception="java.lang.Exception">

             </exception-mapping>

         </global-exception-mappings>

         <action name="errorProcessor" class="cn.itcast.sh.error.ErrorProcess">

             <result>/error.jsp</result>

         </action>

     </package>

     <include file="struts-user.xml"></include>

     <include file="struts-login.xml"></include>

 </struts>

struts-user.xml中

 <?xml version="1.0" encoding="utf-8"?>

    <!DOCTYPE struts PUBLIC

     "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"

     "http://struts.apache.org/dtds/struts-2.3.dtd">

 <struts>

     <package name="user" namespace="/" extends="struts-global">

         <action name="UserAction_*" method="{1}" class="cn.itcast.sh.action.UserAction">

             <result name="userList">/user/list.jsp</result>

         </action>

     </package>

 </struts>

然后如果页面异常都会转向 error.jsp中显示

error.jsp可以进行错误显示

因为信息被放到栈顶了所以可以取到

<s:property />

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