Convert list to string gson android
Learn to use Google GSON library to deserialize or parse JSON, containing json array, to java array or java list objects. Show Its worth mentioning that JSON has only array datatype. Java has both arrays and lists. 1. Parse JSON array as root object[ { "name": "Alex", "id": 1 }, { "name": "Brian", "id": 2 }, { "name": "Charles", "id": 3 } ] public class User { private long id; private String name; public long getId() { return id; } public void setId(long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } @Override public String toString() { return "User [id=" + id + ", name=" + name + "]"; } }1.1. Array of objectsJava program to deserialize json array as root to Java array of objects. String userJson = "[{'name': 'Alex','id': 1}, " + "{'name': 'Brian','id':2}, " + "{'name': 'Charles','id': 3}]"; Gson gson = new Gson(); User[] userArray = gson.fromJson(userJson, User[].class); for(User user : userArray) { System.out.println(user); }Program output. 1.2. List of objectsJava program to deserialize json array as root to Java list of objects. import java.lang.reflect.Type; import java.util.ArrayList; import com.google.gson.Gson; import com.google.gson.reflect.TypeToken; String userJson = "[{'name': 'Alex','id': 1}, " + "{'name': 'Brian','id':2}, " + "{'name': 'Charles','id': 3}]"; Gson gson = new Gson(); Type userListType = new TypeTokenProgram output. User [id=1, name=Alex] User [id=2, name=Brian] User [id=3, name=Charles]2. Parse JSON array as memberGson parses JSON arrays as members without difficulty if they are non-root objects. We can use the fromJson() method in usual manner and it will parse the json array correctly to required java array or list. { "id" : 1, "name" : "HR", "users" : [ { "name": "Alex", "id": 1 }, { "name": "Brian", "id": 2 }, { "name": "Charles", "id": 3 } ]2.1. Member ArrayJava program to deserialize json array as member object to Java array of objects as member field. Program output. Department [id=1, name=HR, users=[User [id=1, name=Alex], User [id=2, name=Brian], User [id=3, name=Charles]]]2.2. Member ListJava program to deserialize json array as member object to Java list of objects a member field. public class Department { private long id; private String name; private ListProgram output. Department [id=1, name=HR, users=[User [id=1, name=Alex], User [id=2, name=Brian], User [id=3, name=Charles]]]Drop me your question related to gson parse JSON array to java lists and arrays. Happy Learning !! References: GSON Github Was this post helpful?Let us know if you liked the post. Thats the only way we can improve. Yes No |