用户登录后的信息存取

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在程序中，用到了验证拦截器 AuthenticationInterceptor 。具体代码如下：

import java.util.Map;

import org.model.User;

import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;


public class AuthenticationInterceptor implements Interceptor  {

     private static final long serialVersionUID = 1L;
     
     private String message;
    
     public static final String USER_SESSION_KEY = "UserSessionKey";
     
     public void destroy() {}

     public void init() {}

     public String intercept(ActionInvocation actionInvocation) throws Exception {
         //取得Session
         Map session = actionInvocation.getInvocationContext().getSession();
         //从Session里获得登录时保存进session的User类
         User user = (User) session.get(USER_SESSION_KEY);
         //如果用户为空，返回登录页面       
         if (user==null||!user.getGrade().equals("2")) {
             this.setMessage("您没登陆或不是管理员");
            return Action.INPUT;           
         }        
         return actionInvocation.invoke();//返回验证通过
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

用户登录的 action 类代码如下：

import java.util.Map;

import org.apache.struts2.interceptor.SessionAware;
import org.dao.impl.UserDaoImpl;
import org.model.User;
import org.web.interceptor.AuthenticationInterceptor;

import com.opensymphony.xwork2.ActionSupport;

public class UserLoginAction extends ActionSupport implements SessionAware{
    private UserDaoImpl dao = new UserDaoImpl();
    
    private String username;
    private String password;
    private Map session;
    
    @Override
    public String execute() throws Exception {
        User user = dao.isValidUser(username, password);
        if (null != user) {
            session.put(AuthenticationInterceptor.USER_SESSION_KEY, user);
            return SUCCESS;
        } else {
            addActionError("用户名与密码不匹配");
            return INPUT;
        }
    }
    
    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;
    }
    
    public Map getSession() {
        return session;
    }

    public void setSession(Map session) {
        this.session = session;
    }
}

这样就把登录用户以 User 类的实例形式存储起来。每次要取出来使用的时候，只需实现 SessionAware 借口，并通过 Map session; session.get(...)的方式即可。如注销用户登录时的代码如下：

import java.util.Map;

import org.apache.struts2.interceptor.SessionAware;
import org.model.User;
import org.web.interceptor.AuthenticationInterceptor;

import com.opensymphony.xwork2.ActionSupport;

public class UserLogoutAction extends ActionSupport implements SessionAware{
    
    private Map session;
    
    public String execute()throws Exception{
        
        //从session取出登陆用户
        System.out.println("******************session====" + session);
        User user =(User)session.get(AuthenticationInterceptor.USER_SESSION_KEY);        
        if(user!=null){
            //从session删除用户
            session.remove(AuthenticationInterceptor.USER_SESSION_KEY);
            addActionError("已注销");
        }
        return INPUT;    
    }
    
    public Map getSession() {
        return session;
    }

    public void setSession(Map session) {
        this.session = session;
    }
}