Struts2 Web资源获取

1、拦截器获取 Web 资源模式

2、静态对象获取 Web 资源模式

1、拦截器获取 Web 资源模式：

（1）使用Struts2 Aware拦截器

index.jsp表单：

<body>
     <form action="<%=path %>/firstAction" method="post">
      姓名：<input type="text" name="name"><br>
      密码：<input type="password" name="pwd"><br>
      <input type="submit" value="登录">
    </form>
</body>

FirstAction.java:

package com.qyy.action;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;
import org.apache.struts2.util.ServletContextAware;

/*  要实现拦截器接口,及其中的抽象方法
 *  三个拦截器分别是 request，response，application
 *  重写它们的抽象方法将private属性初始化
 *  
 *  重写execute方法
 */
public class FirstAction implements ServletRequestAware, ServletResponseAware, ServletContextAware{

	private ServletRequest request;
	private ServletResponse response;
	private ServletContext con;
	
	public String execute() {
		String username = request.getParameter("name");
		System.out.println(username);
		return "success";
	}
	
	@Override
	public void setServletRequest(HttpServletRequest arg0) {
		request = arg0;
	}

	@Override
	public void setServletResponse(HttpServletResponse arg0) {
		response = arg0;
	}

	@Override
	public void setServletContext(ServletContext arg0) {
		con = arg0;
	}
}

struts.xml配置:

<struts>
  <package name="test" extends="struts-default">
    <action name="firstAction" class="com.qyy.action.FirstAction">
      <result name="success">/index.jsp</result>
    </action>
  </package>
</struts>

（2）使用Struts2 RequestAware拦截器

index.jsp表单填写：

<body>
     <form action="<%=path %>/secondAction" method="post">
      姓名：<input type="text" name="name"><br>
      密码：<input type="password" name="pwd"><br>
      <input type="submit" value="登录">
    </form>
</body>

SecondAction.java：

package com.qyy.action;

import java.util.Map;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.struts2.StrutsStatics;
import org.apache.struts2.interceptor.RequestAware;

/*
 * 使用Struts2 RequestAware拦截器
 * 实现RequestAware接口
 * 
 * 这样就完成了程序在走到这个类之前先经过拦截器，
 * 拦截器负责调用这个类的setRequest（）方法将所以Web资源的对象通过map集合获取。
 */
public class SecondAction implements RequestAware{

	private ServletRequest request;
	private ServletResponse response;
	private ServletContext con;
	
	public String execute() {
		String username = request.getParameter("name");
		System.out.println("第二个action  "+username);
		return "success";
	}
	
	@Override
	public void setRequest(Map<String, Object> arg0) {
		request = (ServletRequest) arg0.get(StrutsStatics.HTTP_REQUEST);
		response = (ServletResponse) arg0.get(StrutsStatics.HTTP_RESPONSE);
		con = (ServletContext) arg0.get(StrutsStatics.SERVLET_CONTEXT);
	}

}

Struts.xml配置：

<action name="secondAction" class="com.qyy.action.SecondAction">
      <result name="success">/index.jsp</result>
</action>

2、静态对象获取 Web 资源模式

（1）使用Struts2内置静态对象ActionContext

ThirdAction.java:(比较简便的方法，不用继承或实现任何接口)

package com.qyy.action;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionContext;

/*
 * 比较简便的方法，不用继承或实现任何接口
 */

public class ThirdAction {
	public String execute() {
		ActionContext ac = ActionContext.getContext();
		/*然后就可以使用ac来获得资源
		 */
		ServletRequest request = (ServletRequest) ac.get(ServletActionContext.HTTP_REQUEST);
		ServletResponse response = (ServletResponse) ac.get(ServletActionContext.HTTP_RESPONSE);
		ServletContext con = (ServletContext) ac.get(ServletActionContext.SERVLET_CONTEXT);
		
		String username = request.getParameter("name");
		System.out.println("第三种  "+username);
		
		return "success";
	}
}

　　
（2）使用Struts2内置静态对象ServletActionContext

***推荐使用的一种方式：最方便最简便的方法

package com.qyy.action;

import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.struts2.ServletActionContext;

public class FourthAction {
	public String execute() {
		ServletRequest request = ServletActionContext.getRequest();
		ServletResponse response = ServletActionContext.getResponse();
		ServletContext con = ServletActionContext.getServletContext();
		String username = request.getParameter("name");
		System.out.println("第四种   "+username);
		return "success";
	}
}