struts2之异常处理-优快云博客

struts2提供了很好的异常处理方式，通过声明式的方式管理异常处理。
首先由action抛出异常，再由配置文件进行配置异常处理。
action类：

package com.randy.com;

import java.sql.SQLException;
import java.util.Date;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.interceptor.PreResultListener;

public class LoginAction extends ActionSupport {

	private static final long serialVersionUID = -2503680075934354752L;

	private String username;
	private String password;

	public String execute() throws Exception {
		ActionInvocation invitation = ActionContext.getContext()
				.getActionInvocation();
		invitation.addPreResultListener(new PreResultListener() {

			@Override
			public void beforeResult(ActionInvocation invitation,
					String resultCode) {
				System.out.println(resultCode);
				invitation.getInvocationContext().put("extra",
						new Date() + "由" + resultCode + "转入");
			}
		});
		if ("sql".equalsIgnoreCase(getUsername())) {
			throw new SQLException("can not be exception");
		}
		if ("randy".equals(getUsername()) && "jin".equals(getPassword())) {
			ActionContext.getContext().getSession().put("user", username);
			return SUCCESS;
		}
		return LOGIN;
	}

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

}

然后在struts.xml中配置异常处理：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC 
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" 
"http://struts.apache.org/dtds/struts-2.0.dtd"> 
<struts>
<constant name="struts.custom.i18n.resources" value="mess"></constant>
<constant name="struts.i18n.encoding" value="UTF-8"></constant>
<package name="struts2" extends="struts-default">
	<default-action-ref name="mo"></default-action-ref>
	<global-results>
		<result name="login">/login.jsp</result>
		<result name="error">/error.jsp</result>
		<result name="sql">/exception.jsp</result>
		<result name="exception">/exception.jsp</result>
	</global-results>
	<global-exception-mappings>
		<exception-mapping result="sql" exception="java.sql.SQLException"></exception-mapping>
		<exception-mapping result="exception" exception="java.lang.Exception"></exception-mapping>
	</global-exception-mappings>
	<action name="mo" class="com.randy.com.DefaultAction">
		<result name="success">/welcome.jsp</result>
	</action>
	<action name="login" class="com.randy.com.LoginAction">
		<exception-mapping result="ok" exception="java.lang.NoSuchFieldException"></exception-mapping>
		<result name="success">/welcome.jsp</result>
		<result name="ok">/error.jsp</result>
	</action>
</package> 
</struts>

在目标jsp页面可输出异常信息：

<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<s:property value="exception.message"/>
</body>
</html>

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