struts2笔记之第七讲

struts2笔记之第七讲

导语：Struts2的Action访问Servlet API，有三种方式：上一节课中已经讲了第一方式。可以通过ActionContext访问Servlet API。
三种方式：
1.可以通过ActionContext访问Servlet API 此种方式没有侵入性(这个其实是间接把Session放到中间的map里)

2.可以通过实习装配接口，完成对Servlet API的访问
*ServletRequestAware取得HttpServletRequest对象
*ServletResponseAware取得HttpServletResponse对象
*ServletContextAware取得ServletContext对象（工具类）

3.可以通过ServletActionContext提供的静态方法取得Servlet API
*getPageContext();
*getRequest();
*getResponse();
*getServletContext();

下面折重讲第二中方式和第三种方式，第一种请参阅第一章节。



2.可以通过实习装配接口，完成对Servlet API的访问

例子：
LoginAction.java

package com.struts2;

import java.util.Date;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

public class LoginAction implements Action,ServletRequestAware,ServletResponseAware {
    private String username;
    private String password;
 [color=red]   private HttpServletRequest request;
    private HttpServletResponse response;[/color]
	/**
	 * struts2 默认调用这个方法，返回字符串
	 * @return
	 * @throws Exception
	 */
	public String execute() throws Exception{
		
		
	   if("admin".equals(username) && "admin".equals(password)){
		  request.getSession().setAttribute("user", username);
		   return "success";  
	   }else{
		   return "error";
	   }
		
	}

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

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

	@Override
	public void setServletRequest(HttpServletRequest request) {
		this.request=request;
		
	}
}

MustLoginAction.java

package com.struts2;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.interceptor.ServletRequestAware;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

public class MustLoginAction implements Action,ServletRequestAware {
	  private HttpServletRequest request;
	@Override
	public String execute() throws Exception {
		if(request.getSession().getAttribute("user")==null){
			//重定向到登陆页面
			return LOGIN;
		}else{
			return SUCCESS;
		}
	}
	@Override
	public void setServletRequest(HttpServletRequest request) {
		this.request=request;
		
	}
     
	
}

index.jsp文件核心代码

 <a href="login.jsp">登陆</a> <br>
   <a href="mustLogin.action">访问受保护的页面</a> <br>

省略的jsp页面有：login.jsp、login_error.jsp、login_success.jsp、must_login.jsp

3.可以通过ServletActionContext提供的静态方法取得Servlet API
LoginAction.java

package com.struts2;

import java.util.Date;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.interceptor.ServletRequestAware;
import org.apache.struts2.interceptor.ServletResponseAware;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

public class LoginAction implements Action {
    private String username;
    private String password;
	/**
	 * struts2 默认调用这个方法，返回字符串
	 * @return
	 * @throws Exception
	 */
	public String execute() throws Exception{
		
		
	   if("admin".equals(username) && "admin".equals(password)){
		 ServletActionContext.getRequest().getSession().setAttribute("user", username);
		   return "success";  
	   }else{
		   return "error";
	   }
		
	}

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}		
}

MustLoginAction.java

package com.struts2;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;
import org.apache.struts2.interceptor.ServletRequestAware;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionContext;

public class MustLoginAction implements Action {
	  private HttpServletRequest request;
	@Override
	public String execute() throws Exception {
		if(ServletActionContext.getRequest().getSession().getAttribute("user")==null){
			//重定向到登陆页面
			return LOGIN;
		}else{
			return SUCCESS;
		}
	}