在action中继承ActionSupport 类，重写execute方法
所用到的 jar 包
1.配置web.xml文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_9" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>Struts Blank
</display-name>
<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>
<welcome-file-list>
<welcome-file>index.jsp
</welcome-file>
</welcome-file-list>
</web-app>
2.action接口
package action
;
import com
.opensymphony
.xwork2
.ActionSupport
;
@SuppressWarnings("serial")
public class SumActionSupport extends ActionSupport {
private double x
;
private double y
;
private double sum
;
public String
execute() {
String forward
= "-";
sum
= x
+ y
;
if (sum
> 0)
forward
= "+";
return forward
;
}
public SumActionSupport() {
super();
}
public SumActionSupport(double x
, double y
) {
super();
this.x
= x
;
this.y
= y
;
this.sum
= x
+ y
;
}
public double getX() {
return x
;
}
public void setX(double x
) {
this.x
= x
;
}
public double getY() {
return y
;
}
public void setY(double y
) {
this.y
= y
;
}
public double getSum() {
return sum
;
}
public void setSum(double sum
) {
this.sum
= sum
;
}
}
3.配置struts.xml文件
<?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="default" namespace="/" extends="struts-default">
<action name="opadd" class="action.SumActionSupport" method="execute">
<result name="+">p.jsp
</result>
<result name="-">n.jsp
</result>
</action>
</package>
<include file="example.xml"/>
</struts>
由于action中的execute为默认方法，method属性可以省略
4.input.jsp页面、p.jsp页面、n.jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here
</title>
</head>
<body>
<form action="opadd" method="post">
加数：
<input type="text" name="x">
加数：
<input type="text" name="y">
<input type="submit" value="提交">
</form>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here
</title>
</head>
<body>
${x}+ ${y}= ${sum}
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here
</title>
</head>
<body>
${x}+ ${y}= ${sum}
</body>
</html>
