Struts2 概述:Action中獲取Request

原文轉載至：http://blog.sina.com.cn/s/blog_6c6b2acd0100prx7.html

在Action中獲取：request，session，application。

共四種方式，示例在下面給出，第一種和第三種需要依賴於容器struts，其中第二種最常用。

【注意1】：我們需要知道前兩種方法得到的是Map<String,Object>,而後兩種方式得到的纔是真正的request等對象。而Map就是把request對象中的屬性取出做成了鍵值對而已。

【注意2】：另外如果就是爲了在action和jsp傳遞參數的話，只需要在action中定義成員，然後Jsp中利用struts標籤<s:property value="name"/>就能夠訪問到數據，而這些內容都是被保存在了value stack中。關於value stack 和 stack context 會在後面得內容涉及。

 

方法一：

    public class LoginAction1 extends ActionSupport {
    private Map request;
    private Map session;
    private Map application;
    public LoginAction1() {
       request = (Map)ActionContext.getContext().get("request");
        session = ActionContext.getContext().getSession();
        application = ActionContext.getContext().getApplication();
    }
    public String execute() {
        request.put("r1", "r1");
        session.put("s1", "s1");
        application.put("a1", "a1");
        return SUCCESS;
    }
}

方法二：

public class LoginAction2 extends ActionSupport implements RequestAware,SessionAware, ApplicationAware {
    private Map<String, Object> request;
    private Map<String, Object> session;
    private Map<String, Object> application;
    //DI dependency injection
    //IoC inverse of control
    public String execute() {
        request.put("r1", "r1");
        session.put("s1", "s1");
        application.put("a1", "a1");
        return SUCCESS;
    }

    @Override
    public void setRequest(Map<String, Object> request) {
        this.request = request;
    }

    @Override
    public void setSession(Map<String, Object> session) {
        this.session = session;
    }

    @Override
    public void setApplication(Map<String, Object> application) {
        this.application = application;
    }
}

方法三：

public class LoginAction3 extends ActionSupport {
    private HttpServletRequest request;
    private HttpSession session;
    private ServletContext application;
    public LoginAction3() {
        request = ServletActionContext.getRequest();
        session = request.getSession();
        application = session.getServletContext();
    }
    public String execute() {
        request.setAttribute("r1", "r1");
        session.setAttribute("s1", "s1");
        application.setAttribute("a1", "a1");
        return SUCCESS;
    }
}

方法四：

    public class LoginAction4 extends ActionSupport implements ServletRequestAware {
    private HttpServletRequest request;
    private HttpSession session;
    private ServletContext application;
    public String execute() {
        request.setAttribute("r1", "r1");
        session.setAttribute("s1", "s1");
        application.setAttribute("a1", "a1");
        return SUCCESS;
    }

   @Override
    public void setServletRequest(HttpServletRequest request) {
        this.request = request;
        this.session = request.getSession();
        this.application = session.getServletContext();
    }
}