Struts2方法调用的三种方式(有新的!调用方法的说明)
在Struts2中方法调用概括起来主要有三种形式
第一种方式：指定method属性
<action name="heroAction" class="com.ABC123.HeroAction" method="add">
<result name="add">/add.jsp</result>
</action>
这样Struts2就会调用heroAction中的add方法。
第二种方式：动态方法调用(DMI)
用这种方法需要设置一个常量
struts2的2.3以上版本的jar包 必须配置DMI
<constant name="struts.enable.DynamicMethodInvocation" value="true" />
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd"> <struts> <constant name="struts.enable.DynamicMethodInvocation" value="true" /> <package name="goToEat" namespace="/" extends="struts-default"> <action name="heroAction" class="com.ABC123.action.HeroAction" > <result name="list" >/list.jsp</result> <result name="gotoupd" >/upd.jsp</result> <!-- 重定向--> <result name="add" type="redirect">heroAction!list.action</result> </action> </package> </struts>
动态方法调用是指表单元素的action并不是直接等于某个Action的名字，而是以如下形式来指定Form的action属性
<!-- action属性为action!methodName的形式 -->
action = "action!methodName.action"
在struts.xml中定义如下Action
<package name="goToEat" namespace="/" extends="struts-default"> <action name="heroAction" class="com.ABC123.action.HeroAction" > <result name="list" >/list.jsp</result> <result name="gotoupd" >/upd.jsp</result> <!-- 重定向--> <result name="add" type="redirect">heroAction!list.action</result> </action> </package>
HeroAction中的方法为
package com.ABC123.action;
import java.util.ArrayList;
import java.util.List;
import com.ABC123.pojo.Hero;
public class HeroAction {
private static List<Hero> heroList=new ArrayList<Hero>();
private Hero hero;
private int id;
static{
heroList.add(new Hero(1, "德玛", 12, "德玛西亚", "很难哦哦"));
heroList.add(new Hero(2, "艾希", 45, "德玛西亚", "很厉害的啊"));
heroList.add(new Hero(3, "亚索", 78, "小学生", "很牛逼"));
}
public String list() {
return "list";
}
//增加
public String add() {
System.out.println(hero);
heroList.add(hero);
return "add";
}
//删除
public String del() {
System.out.println("删除的下标===>"+id);
Hero hero2 = heroList.get(id);
System.out.println(hero2);
heroList.remove(hero2);
return "add";
}
public String goToUpd() {
Hero hero5 = heroList.get(id);
System.out.println("该条点击修改的的hero==>"+hero5);
return "gotoupd";
}
//修改
public String upd() {
System.out.println(hero.getId());
int id2 = hero.getId();
id2-=1;
System.out.println("id2===>"+id2);
//修改前
Hero hero5 = heroList.get(id2);
System.out.println("该条点击修改的的hero==>"+hero5);
//接到的值为hero
hero5.setAge(hero.getAge());
hero5.setName(hero.getName());
hero5.setStory(hero.getStory());
hero5.setZhenying(hero.getZhenying());
// heroList.set(id2, hero);
System.out.println("修改后的hero==>"+hero);
return "add";
}
//================================
public List<Hero> getHeroList() {
return heroList;
}
public void setHeroList(List<Hero> heroList) {
this.heroList = heroList;
}
public Hero getHero() {
return hero;
}
public void setHero(Hero hero) {
this.hero = hero;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
}
则在JSP中用如下方式调用方法
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ 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=UTF-8">
<title>Insert title here</title>
</head>
<body>
<a href="/struts-01/add.jsp">去添加</a>
</br>
</br>
<table border="1">
<tr>
<td>id</td>
<td>name</td>
<td>age</td>
<td>zhenying</td>
<td>story</td>
<td colspan="2">操作</td>
</tr>
<c:forEach items="${heroList }" var="hero">
<tr>
<td>${hero.id }</td>
<td>${hero.name }</td>
<td>${hero.age }</td>
<td>${hero.zhenying }</td>
<td>${hero.story }</td>
<td><a href="heroAction!goToUpd.action?id=${hero.id -1}">修改</a></td>
<td><a href="heroAction!del.action?id=${hero.id -1 }">删除</a></td>
</tr>
</c:forEach>
</table>
<hr>
<a href="/struts-01/add.jsp">去添加</a>
</br>
</br>
<table border="1">
<tr>
<td>id</td>
<td>name</td>
<td>age</td>
<td>zhenying</td>
<td>story</td>
<td colspan="2">操作</td>
</tr>
<s:iterator value="heroList">
<tr>
<td><s:property value="id"/></td>
<td><s:property value="name "/></td>
<td><s:property value="age "/></td>
<td><s:property value="zhenying "/></td>
<td><s:property value="story "/></td>
<td><a href="heroAction!goToUpd.action?id=<s:property value='id-1'/>">修改</a></td>
<td><a href="heroAction!del.action?id=<s:property value='id-1'/>">删除</a></td>
</tr>
</s:iterator>
</table>
</body>
</html>
第三种方式：通配符（推荐使用）
<action name="heroAction_*" class="com.ABC123.action.HeroAction" method="{1}">
<result name="list" >/list.jsp</result>
</action>
这里的{1} 相当于传进来字符串进行拼接地址 比如传进来list 拼接为/list.jsp
<action name="heroAction_*" class="com.ABC123.action.HeroAction" method="{1}">
<result name="{1}" >/{1}.jsp</result>
</action>
<a href="heroAction_list.action">查询 <a href="heroAction_add.action">增加
heroAction_list.action就会调用heroAction中的list方法 然后跳转到list.jsp
heroAction_add.action就会调用heroAction中的add方法 然后跳转到add.jsp
