java - JSON: use deserializing name different than serializing name json -

i have 1 class user, received json (for user class) system1 , should read info , validate forward system2, can't touch these 2 systems, problem names of keys different, want differentiate between deserialized , serialized name received json :

{"userid":"user1","pwd":"123456","country":"us"}

"{"username":"user1","password":"123456","country":"us"}"

but sent should

i using gson lib, , code, please help

user class:

public class user implements cloneable {      @serializedname("username")     private string username ;      @serializedname("password")     private string password ;      @serializedname("country")     private string country ;        public user(string username, string password, string country) {         super();         this.username = username;         this.password = password;         this.country = country;     }        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 string getcountry() {         return country;     }      public void setcountry(string country) {         this.country = country;     } } 

testjson class:

import com.google.gson.gson; import com.google.gson.gsonbuilder;  public class testjson {       private static gsonbuilder gsonbuilder;     private static gson gson;       public static object fromjson(string json, class clz) {         gson = new gson();         return gson.fromjson(json, clz);     }      public static string tojson(object obj) {         gsonbuilder = new gsonbuilder();         gson = gsonbuilder.create();         string json = gson.tojson(obj);         return json;     }      public static void main(string[] args) {            string json2 = "{\"userid\":\"user1\",\"pwd\":\"123456\",\"country\":\"us\"}";          user user=(user) testjson.fromjson(json2, user.class);           system.out.println(user.getpassword());          user u =new user("user1","123456","us");         string json1=testjson.tojson(u);          system.out.println(json1);        } } 

you can create custom serializer/deserializer purpose.

serializer:

public class userserializer implements jsonserializer<user> {     @override public jsonelement serialize(user obj, type type, jsonserializationcontext jsonserializationcontext) {         ..........     } } 

deserializer:

public class userdeserializer implements jsondeserializer<user> {     @override public user deserialize(jsonelement json, type typeoft, jsondeserializationcontext context) throws jsonparseexception {         ...........     } } 

and create gson instance:

gsonbuilder gsonbuilder = new gsonbuilder(); gsonbuilder.registertypeadapter(user.class, new userserializer()); gsonbuilder.registertypeadapter(user.class, new userdeserializer()); gson gson = gsonbuilder.create(); 

example

edit: example of custom deserializer might fit need. don't need custom serializer in case.

add userdeserializer.java:

public class userdeserializer implements jsondeserializer<user> {     @override     public user deserialize(jsonelement json, type typeoft, jsondeserializationcontext context) throws jsonparseexception {         jsonobject obj = json.getasjsonobject();         user user = new user(obj.get("userid").getasstring(), obj.get("pwd").getasstring(), obj.get("country").getasstring());         return user;     } } 

replace fromjson implementation (i use generic avoid need casting when calling fromjson):

public static <t> t fromjson(string json, class<t> clz) {     gsonbuilder = new gsonbuilder();     gsonbuilder.registertypeadapter(user.class, new userdeserializer());     gson = gsonbuilder.create();     return gson.fromjson(json, clz); }