How to Convert String Array JSON in a Java Object

Question

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• Convert a JSON string to object in Java ME? 14 answers

i need to convert this String JSON to a Java Object:

{"estabelecimento":[{"id":"5","idUsuario":"5","razaoSocial":"Bibi LTDA","nomeFantasia":"BibiPizza","telefone":"22121212","email":"[e-mail]","gostaram":"0"},{"id":"8","idUsuario":"1","razaoSocial":"Nestor Latuf LTDA","nomeFantasia":"Nestor Sorvetes","telefone":"32343233","email":"[e-mail]","foto":"","gostaram":"0"},{"id":"9","idUsuario":"1","razaoSocial":"Comercio Alimenticio Rivaldo","nomeFantasia":"Rogers Burguer","telefone":"210021020","email":"[e-mail]","foto":"","gostaram":"0"}]}

I try this, but not work:

 //JSONArray jArr = new JSONArray(br.toString());  

        //JSONObject jObj = new JSONObject(br.toString());

        //JSONArray jArr = jObj.getJSONArray("list");

        JSONArray jArr = new JSONArray(br.toString());

        for (int i=0; i < jArr.length(); i++) {
            JSONObject obj = jArr.getJSONObject(i);
            estabelecimento.setId(obj.getLong("id"));
            estabelecimento.setIdUsuario(obj.getLong("idUsuario"));
            estabelecimento.setRazaoSocial(obj.getString("razaoSocial"));
            estabelecimento.setNomeFantasia(obj.getString("nomeFantasia"));
            estabelecimento.setTelefone(obj.getString("telefone"));
            estabelecimento.setEmail(obj.getString("email"));
            estabelecimento.setGostaram(obj.getInt("gostaram"));

            estabelecimentoList.add(estabelecimento);
        }
        con.disconnect();

How can i obtain a Java Object? Someone can help? tks.

Answer 1

You can use the Gson lib of google:

public class MyClass {

    private int data1 = 100;
    private String data2 = "hello";
    private List<String> list = new ArrayList<String>() {
      {
        add("String 1");
        add("String 2");
        add("String 3");
      }
    };

    //getter and setter methods needed


}


String str = {"data1":100,"data2":"hello","list":["String 1","String 2","String 3"]};
com.google.gson.Gson gson = new com.google.gson.Gson();

//To convert json string to class use fromJson
MyClass obj = gson.fromJson(str, MyClass .class);

//To convert class object to json string use toJson
String json = gson.toJson(obj);

Answer 2

At high level two major steps:

1. Generate a Java class from your JSON, e.g. by using this generator or similar: http://www.jsonschema2pojo.org/

2. Use Jackson processor to deserialize your JSON file:

    ObjectMapper mapper = new ObjectMapper();
    YourGeneratedClass obj = (YourGeneratedClass) mapper.readValue(new File("path-to-your-json-file"), YourGeneratedClass.class);
   

More about Jackson: http://jackson.codehaus.org/

You can also create YourGeneratedClass manually if you feel comfortable enough with this.