java - Input 3 Attributes Into HashMap Key -

i new java. using hashmap purpose store data mysql database , use json post request input user , search related data in hashmap , retrieve hashmap. need 3 inputs user in hashmap able input 1 key. so, tried way input key object not working. below code storing data mysql database.

public class appdataservice { hashmap<appdatarequest, appdata> appdatas = new hashmap<appdatarequest, appdata>();  static final string jdbc_driver = "com.mysql.jdbc.driver"; static final string db_url = "jdbc:mysql://****:3306/****_demo";  static final string user = "****"; static final string pass = "****";  public appdataservice(){     connection conn = null;     statement stat = null;     try{         class.forname("com.mysql.jdbc.driver");         conn = drivermanager.getconnection(db_url, user, pass);         stat = conn.createstatement();         string sql = "select * testdata";         resultset resu = stat.executequery(sql);         while(resu.next()){             int id = resu.getint("app_id");             string email = resu.getstring("email");             string password = resu.getstring("password");             string status = resu.getstring("status");             string message = resu.getstring("message");             string token = resu.getstring("token");             appdatas.put(new appdatarequest(id, email, password), new appdata(status, message, token));         }         resu.close();         stat.close();         conn.close();     }     catch(sqlexception se){         se.printstacktrace();     }     catch(exception e){         e.printstacktrace();     }     finally{         try{             if(stat!=null){                 stat.close();             }         }         catch (sqlexception se2){          }         try{             if(conn!=null){                 conn.close();             }         }         catch(sqlexception se3){             se3.printstacktrace();         }     }        }      public list<appdata> getallappdata(){         return new arraylist<appdata>(appdatas.values());     }      public appdata getappdata(int id){         return appdatas.get(id);     }      public appdata getsappdata(int id, string email, string password){         return appdatas.get(new appdatarequest (id, email, password));     } } 

my json post code

@path("/appdata") @consumes(mediatype.application_json) @produces(mediatype.application_json)  appdataservice ads = new appdataservice();  @post @path("/appdatas") public appdata getsappdata(appdatarequest adr){     return ads.getsappdata(adr.getid(), adr.getemail(),adr.getpassword()); } 

appdata class

public class appdata {     public string status;     public string message;     public string token;      public appdata(){      }         public appdata(string status, string message, string token) {         this.status = status;         this.message = message;         this.token = token;     }      public string getstatus() {         return status;     }      public void setstatus(string status) {         this.status = status;     }      public string getmessage() {         return message;     }      public void setmessage(string message) {         this.message = message;     }      public string gettoken() {         return token;     }      public void settoken(string token) {         this.token = token;     } } 

appdatarequest class

public class appdatarequest {     public int id;     public string email;     public string password;      public appdatarequest(){      }      public appdatarequest(int id, string email, string password) {         this.id = id;         this.email = email;         this.password = password;     }      public int getid() {         return id;     }      public void setid(int id) {         this.id = id;     }      public string getemail() {         return email;     }      public void setemail(string email) {         this.email = email;     }      public string getpassword() {         return password;     }      public void setpassword(string password) {         this.password = password;     } } 

you can overide hashcode , equals in class :

@override public int hashcode() {     int hash = 3;     hash = 83 * hash + this.id;     hash = 83 * hash + objects.hashcode(this.email);     hash = 83 * hash + objects.hashcode(this.password);     return hash; }  @override public boolean equals(object obj) {     if (this == obj) {         return true;     }     if (obj == null) {         return false;     }     if (getclass() != obj.getclass()) {         return false;     }     final appdatarequest other = (appdatarequest) obj;     if (this.id != other.id) {         return false;     }     if (!objects.equals(this.email, other.email)) {         return false;     }     if (!objects.equals(this.password, other.password)) {         return false;     }     return true; } 

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why don't make id key if unique in table, , other information value of map :

map<integer, appdata> appdatas; appdatas.put(id, new appdata(status, message, token, email, password));