Struts2访问Servlet的三种方式

package com.pc.web.action; 
import javax.servlet.ServletContext; 
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; 
 
import com.opensymphony.xwork2.ActionSupport; 
 
/** 
 * 使用特定接口访问Servlet对象 
 * @author Switch 
 * 
 * org.apache.struts2.dispatcher.StrutsRequestWrapper@461aa2 
 * org.apache.catalina.connector.ResponseFacade@7e83df 
 * org.apache.catalina.core.ApplicationContextFacade@3b102 
 * org.apache.catalina.session.StandardSessionFacade@5a214b 
 * 是由一个名称为servletConfig的拦截器为我们封装的 
 */ 
public class ActionTest7 extends ActionSupport implements ServletRequestAware,ServletResponseAware,ServletContextAware { 
 
  private HttpServletRequest request; 
  private HttpServletResponse response; 
  private ServletContext application; 
 
  /** 
   * @return 
   */ 
  public String demo(){ 
    System.out.println(request); 
    System.out.println(response); 
    System.out.println(application); 
    System.out.println(request.getSession()); 
    return SUCCESS; 
  } 
 
  @Override 
  public void setServletRequest(HttpServletRequest request) { 
    this.request = request; 
  } 
 
  @Override 
  public void setServletResponse(HttpServletResponse response) { 
    this.respOnse= response; 
  } 
 
  @Override 
  public void setServletContext(ServletContext application) { 
    this.application = application; 
  } 
} 

package com.pc.struts2.web.action;  
import javax.servlet.ServletContext; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import javax.servlet.http.HttpSession; 
 
import org.apache.struts2.ServletActionContext; 
 
import com.opensymphony.xwork2.ActionSupport; 
/** 
 * 访问ServletAPI的方式 
 * 
 * 使用Struts2框架提供了一个工具类： 
 *     ServletActionContext 
 * 它里面提供了对应的静态方法，可以直接获取ServletAPI 
 * 
 * 有一个需要注意的问题： 
 *    org.apache.struts2.dispatcher.StrutsRequestWrapper@4637b3 
 *    org.apache.catalina.connector.ResponseFacade@1f2f2f7 
 *    org.apache.catalina.session.StandardSessionFacade@12d77c1 
 *    org.apache.catalina.core.ApplicationContextFacade@1133ff 
 * 
 *    requet对象已经不是原来tomcat提供的了，而是被struts2框架包装过了。 
 *     包装使用的是装饰者模式。 
 *    装饰者模式的作用是对方法进行增强。 
 * 
 * @author Switch 
 */ 
public class ActionAPITest extends ActionSupport { 
  /** 
   * 在Struts2框架中使用ServletAPI 
   * @return 
   */ 
  public String useServletAPI() { 
    HttpServletRequest request = ServletActionContext.getRequest(); 
    HttpServletResponse respOnse= ServletActionContext.getResponse(); 
    HttpSession session = request.getSession(); 
    ServletContext application = ServletActionContext.getServletContext(); 
    System.out.println(request); 
    System.out.println(response); 
    System.out.println(session); 
    System.out.println(application); 
    return "success"; 
  } 
} 

package com.pc.web.action;  
import java.util.Map;  
import javax.servlet.ServletContext; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import javax.servlet.http.HttpSession; 
 
import org.apache.struts2.ServletActionContext; 
import org.apache.struts2.StrutsStatics; 
 
import com.opensymphony.xwork2.ActionContext; 
import com.opensymphony.xwork2.ActionSupport; 
 
/** 
 * ActionContext类介绍 
 *   它是Struts2框架为我们提供的一个工具类。 
 *   该类可以通过方法直接获取request,response,servletContext对象 
 * @author Switch 
 * 
 * context.getParameters(); == request.getParameterMap(); 获取的是请求参数 
 */ 
public class ActionTest8 extends ActionSupport implements StrutsStatics { 
 
  private HttpServletRequest request; 
  private HttpServletResponse response; 
  private ServletContext application; 
 
  /** 
   * 使用ActionContext访问ServletAPI 
   * @return 
   */ 
  public String demo(){ 
    ActionContext cOntext= ActionContext.getContext(); 
 
    request = (HttpServletRequest) context.get(HTTP_REQUEST); 
    respOnse= (HttpServletResponse) context.get(HTTP_RESPONSE); 
    application = (ServletContext) context.get(SERVLET_CONTEXT); 
    System.out.println(request); 
    System.out.println(response); 
    System.out.println(application); 
    System.out.println(request.getSession()); 
    /*org.apache.struts2.dispatcher.StrutsRequestWrapper@112e422 
    org.apache.catalina.connector.ResponseFacade@13f8b4c 
    org.apache.catalina.core.ApplicationContextFacade@d244dd 
    org.apache.catalina.session.StandardSessionFacade@a711cb*/ 
 
    return SUCCESS; 
  } 
 
  /** 
   * 使用原始ServletAPI对象，往session域和application域中存入数据 
   * session域中存入     key=sessionAttr     value=hello session attr 
   * application域中存入 key=applicationAttr   value=hello application attr 
   * @return 
   */ 
  public String demo2(){ 
    //1.获取session对象 
    HttpSession session = ServletActionContext.getRequest().getSession(); 
    //存入数据 
    session.setAttribute("sessionAttr", "hello session attr"); 
    session.getId(); 
    //2.获取ServletContext 
    ServletContext application = ServletActionContext.getServletContext(); 
    application.getRealPath("/WEB-INF/uploads"); 
    //存入数据 
    application.setAttribute("applicationAttr", "hello application attr"); 
    return SUCCESS; 
  } 
 
 
  /** 
   * 使用ActionContext类中的getSession()和getApplication()获取到的map来往map中存入数据 
   * sessionMap中存入     key=sessionAttr     value=hello session map 
   * applicationMap中存入 key=applicationAttr   value=hello application map 
   * @return 
   */ 
  public String demo3(){ 
    //1.获取ActionContext对象 
    ActionContext cOntext= ActionContext.getContext(); 
    //2.获取sessionMap 
    Map sessiOnMap= context.getSession(); 
    sessionMap.put("sessionAttr", "hello session map"); 
    //3.获取applicationMap 
    Map applicatiOnMap= context.getApplication(); 
    applicationMap.put("applicationAttr", "hello application map"); 
    return SUCCESS; 
  } 
 
}