Struts2提供的后台效验流程
- 拦截器调用指定的方法
validate()方法； - 判断保存错误的Map集合是否为空，为null，才执行action的
execute()方法； - 如果不为null, 说明验证有错误，不放行。
数据效验原理
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public synchronized void addFieldError(String fieldName, String errorMessage) {
// 保存所有的错误信息的map集合
// 同一个key，可以对应多个值
final Map> errors = internalGetFieldErrors();
// 先根据当前错误的key，去错误的map集合中查找，看是否已经存在！
List thisFieldErrors = errors.get(fieldName);
// 当前错误的key，在map集合不存在
if (thisFieldErrors == null) {
thisFieldErrors = new ArrayList();
errors.put(fieldName, thisFieldErrors);
}
// 设置错误信息！
thisFieldErrors.add(errorMessage);
}
错误处理
配置错误视图标记input对应的JSP页面，出现错误跳转到index.jsp，合理显示错误信息。
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<package name="animal" namespace="" extends="person">
<action name="a1" class="com.bbs.action.AnimalAction">
<result name="success">/WEB-INF/success.jsp</result>
<result name="error">/WEB-INF/error.jsp</result>
<result name="input">/index.jsp</result>
</action>
</package>
目录结构
web.xml
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<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>Struts2MVCDemo</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
struts.xml
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<!-- 不需要默认Spring容器管理struts -->
<constant name="struts.objectFactory"
value="com.opensymphony.xwork2.ObjectFactory"></constant>
<!-- 开发阶段，struts配置修改，重新加载 -->
<constant name="struts.configuration.xml.reload" value="true"></constant>
<package name="person" namespace="/person" extends="struts-default">
<action name="hello1" class="com.bbs.action.PersonAction">
<result name="success">/WEB-INF/success.jsp</result>
</action>
<action name="hello2" class="com.bbs.action.PersonAction" method="zhangxueyou">
<result name="success">/WEB-INF/success.jsp</result>
<result name="error">/WEB-INF/error.jsp</result>
</action>
<action name="hello3" class="com.bbs.action.PersonAction" method="liming">
<result name="success">/WEB-INF/success.jsp</result>
<result name="error">/WEB-INF/error.jsp</result>
</action>
</package>
<include file="struts*.xml"></include>
</struts>
struts1.xml
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<package name="animal" namespace="" extends="person">
<action name="a1" class="com.bbs.action.AnimalAction">
<result name="success">/WEB-INF/success.jsp</result>
<result name="error">/WEB-INF/error.jsp</result>
<result name="input">/index.jsp</result>
</action>
</package>
</struts>
PersonAction.java
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package com.bbs.action;
// struts2 Action层
public class PersonAction {
private String name;
// 视图从值栈中获取name
public String getName() {
System.out.println("调用getName方法");
return name;
}
public void setName(String name) {
System.out.println("调用setName方法，在actionContext中记录值栈信息");
this.name = name;
}
// 默认执行
public String execute() {
// 返回result结果,视图名字
return "success";
}
public String zhangxueyou() {
if (true) {
return "success";
} else {
return "error";
}
}
public String liming() {
System.out.println("获取页面参数：" + name);
if (name == null || name.equals("")) {
return "error";
}
return "success";
}
}
AnimalAction.java
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package com.bbs.action;
import com.opensymphony.xwork2.ActionSupport;
/**
* action 模型，处理animal方法
* ActionSupport类不仅实现了action接口。还实现了：
* validateable 提供校验功能
* validationAware 提供校验功能
* textprovider 提供国际化支持
* localprovider 提供国际化支持
* serializable 序列化接口
* 所以，更多情况下，我们需要继承ActionSupport类
* @author Administrator
*/
public class AnimalAction extends ActionSupport {
private static final long serialVersionUID = 1L;
private String name;
private String pwd;
public String getName() {
return name;
}
public String getPwd() {
return pwd;
}
public void setName(String name) {
this.name = name;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String login() {
if (name.trim().equals("mayi") && pwd.trim().equals("123")) {
return "success";
} else {
return "error";
}
}
public void validate() {
// 验证
if (name == null || pwd == null) {
addFieldError(name, "不能为空！");
}
}
}
success.jsp
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<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!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=UTF-8">
<title>Success页面</title>
</head>
<body>
success获取值栈属性值：${name }
<s:debug></s:debug>
</body>
</html>
index.jsp
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<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>Index页面</title>
</head>
<body>
index
<a href="http://localhost:8080/Struts2MVCDemo/person/hello1">
请求链接-------PersonAction中的方法
</a>
</body>
</html>
error.jsp
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<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>Error页面</title>
</head>
<body>
success
</body>
</html>