javaWeb Servlet简单应用代码

                  Bean 类

package Bean;

public class DayBean {
    public int id;
    public String uid;
    public String img_path;
    public String time;
    public String reviews;
    public String status;    //对错情况
    public String mistakes;  //错误次数
}
------------------------------------------
package Bean;

import com.google.gson.Gson;

/**
 * @author HandsomeXi
 * @date 2018-12-12 13:16
 */
public class LoginResultBean {
    public int code;
    public String msg;
    public UserBean user;

    public LoginResultBean(int code, String msg) {
        this.code = code;
        this.msg = msg;

        user = null;
    }

    public LoginResultBean(int code, String msg, UserBean user) {
        this.code = code;
        this.msg = msg;
        this.user = user;
    }
    public String toJson(){
        return new Gson().toJson(this);
    }
}
---------------------------------------------------
package Bean;

import com.google.gson.Gson;

/**
 * @author HandsomeXi
 * @date 2018-12-12 13:22
 */
public class MsgBean {
    public int code;
    public String msg;

    public MsgBean(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }
    public String toJson(){