Create JSON String using GSON

Question

I am having a class like following,

public class Student {
    public int id;
    public String name;
    public int age;    
}

Now I want to c

Answer 1

Better is to use @expose annotation like

public class Student {
    public int id;
    @Expose
    public String name;
    @Expose
    public int age;
}

And use below method to get Json string from your object

private String getJsonString(Student student) {
    // Before converting to GSON check value of id
    Gson gson = null;
    if (student.id == 0) {
        gson = new GsonBuilder()
        .excludeFieldsWithoutExposeAnnotation()
        .create();
    } else {
        gson = new Gson();
    }
    return gson.toJson(student);
}

It will ignore id column if that is set to 0, either it will return json string with id field.