struts2中的Action

1.Struts2的Action可以不需实现任何接口或继承任何类，就是一个包含了execute()方法的POJO,下面是一个简单的Action的实现

 

package com;

import com.opensymphony.xwork2.ActionContext;
public class LogonAction {
	private String userName;
	private String userPwd;
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getUserPwd() {
		return userPwd;
	}
	public void setUserPwd(String userPwd) {
		this.userPwd = userPwd;
	}
	public String execute(){
		
		if(userName.equals("callan") && userPwd.equals("fjf")){
			
			// ActionContext的getSession()返回的不是一个HttpSession,是一个Map
			// 但struts2的拦截器会负责该session与httpsession的转换
			ActionContext.getContext().getSession().put("userName", "callan");
			return "succee";
		} else {
			return "error";
		}
	}
}

 

 

配置文件

 

<package name="logon" extends="struts-default">
        <action name="logon" class="com.LogonAction">
            <result name="succee">/logon/welcome.jsp</result>
            <result name="error">/logon/error.jsp</result>
        </action>
 </package>

 

 

当请求时,Struts运行时根据struts.xml里的Action映射,实例化com.LogonAction类,

默认情况下会调用其execute方法。不过我们可以通过配置改变他的方法,配置如下:

 

<action name="logon" method="userLogon" class="com.LogonAction">
            <result name="succee">/logon/welcome.jsp</result>
            <result name="error">/logon/error.jsp</result>
 </action>

 

 

Method配置调用的方法名为userLogon,这时当请求logon.action时会调用userLogon()方法，不会在去调用默认的execute()方法

 

 

 

2. 虽然Action可以不实现任何接口或继承任何类,但大多数情况下都会继承com.opensymphony.xwork2.ActionSupport类，并重载execute()方法．(比如说我们需要request和response对象时)

 

public class LogonAction2 extends ActionSupport{
	private String userName;
	private String userPwd;
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getUserPwd() {
		return userPwd;
	}
	public void setUserPwd(String userPwd) {
		this.userPwd = userPwd;
	}
	public String execute(){
		// 得到request对象
		HttpServletRequest request = ServletActionContext.getRequest();
		HttpServletResponse response = ServletActionContext.getResponse();
		return SUCCESS;
	}
}

 

 

SUCCESS是在ActionSupport定义的,同时还定义了ERROR,INPUT,LOGIN,NONE,在配置result的name时,他们的值分别为success,error,input,login,none 3.继承ActionSupport类能得到request,response等对象,通过ioc方式也能得到request,response(实现ServletRequestAware, ServletResponseAware接口)

 

public class LogonAction implements SessionAware, ServletRequestAware, ServletResponseAware {
	private String userName;
	private String userPwd; 
	private Map session;
	private HttpServletRequest request; 
	private HttpServletResponse response;
	public String execute(){
		// session是一个map
		// struts2的拦截器会负责该session与httpsession的转换
// 在页面上取值和在session中取一样.session.getAttribute(userName)
		session.put("userName", "callan");
		
		return "succee";
		
	}
	public void setSession(Map session) {
		this.session = session;
	}
	public void setServletRequest(HttpServletRequest request) {
		this.request = request;
	}
	public void setServletResponse(HttpServletResponse response) {
		this.response = response;
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getUserPwd() {
		return userPwd;
	}
	public void setUserPwd(String userPwd) {
		this.userPwd = userPwd;
	}
}