Struts 2--Struts 2访问ServletAPI对象

ServletAP解析：API(Application Programming Interface) 应用程序编程接口。

　　　ServletAPI就是和Servlet相关的一组接口和类。

　　为了能够实现对ServletAPI对象的访问，Struts 2 提供了多种方式，但归结起来可分为两大类：

　　1.与ServletAPI解耦的访问方式

　　2.与ServletAPI耦合的访问方式

下面介绍解耦方式：　　

1.使用ActionContex类获取ServletAPI对象对应的Map对象。

public class LoginAction implements Action {

    private UserInfo user =new UserInfo();
    @Override
    public String execute() throws Exception {

        if(user.getUserName().equals("admin") && user.getPassword().equals("admin")){

             Map<String, Object> session = ActionContext.getContext().getSession();
             session.put("name", user.getUserName());
            return "success";
        }else{
            return "error";
        }
    }
    public UserInfo getUser() {
        return user;
    }
    public void setUser(UserInfo user) {
        this.user = user;
    }

}

2.向Action注入ServletAPI对象对应的Map对象

public class LoginAction implements Action,SessionAware {

    private UserInfo user =new UserInfo();
    private Map<String, Object> map;

    @Override
    public String execute() throws Exception {

        if(user.getUserName().equals("admin") && user.getPassword().equals("admin")){

            map.put("name", user.getUserName());
            return "success";
        }else{
            return "error";
        }
    }

    //SessionAware实现方法
    @Override
    public void setSession(Map<String, Object> map) {
        this.map=map;
    }

    public UserInfo getUser() {
        return user;
    }
    public void setUser(UserInfo user) {
        this.user = user;
    }

    public Map<String, Object> getMap() {
        return map;
    }
    public void setMap(Map<String, Object> map) {
        this.map = map;
    }

}

第三种：

public class LoginAction implements Action,ServletRequestAware {

    private UserInfo user =new UserInfo();
    private HttpServletRequest request;

    @Override
    public String execute() throws Exception {

        if(user.getUserName().equals("admin") && user.getPassword().equals("admin")){

            request.setAttribute("name", user.getUserName());
            return "success";
        }else{
            return "error";
        }
    }

    //ServletRequestAware实现方法
    @Override
    public void setServletRequest(HttpServletRequest request) {
        this.request=request;
    }

    public HttpServletRequest getRequest() {
        return request;
    }

    public void setRequest(HttpServletRequest request) {
        this.request = request;
    }

    public UserInfo getUser() {
        return user;
    }
    public void setUser(UserInfo user) {
        this.user = user;
    }

}

耦合方式：

第一种：

public class LoginAction implements Action {

    private UserInfo user =new UserInfo();
    @Override
    public String execute() throws Exception {

        if(user.getUserName().equals("admin") && user.getPassword().equals("admin")){

            HttpSession session = ServletActionContext.getRequest().getSession();
            session.setAttribute("name", user.getUserName());
            return "success";
        }else{
            return "error";
        }
    }
    public UserInfo getUser() {
        return user;
    }
    public void setUser(UserInfo user) {
        this.user = user;
    }
}

第二种：

public class LoginAction implements Action {

    private UserInfo user =new UserInfo();
    @Override
    public String execute() throws Exception {

        if(user.getUserName().equals("admin") && user.getPassword().equals("admin")){

            Map<String, Object> session = ServletActionContext.getContext().getSession();
            session.put("name", user.getUserName());
            return "success";
        }else{
            return "error";
        }
    }
    public UserInfo getUser() {
        return user;
    }
    public void setUser(UserInfo user) {
        this.user = user;
    }

}