ajduke

Default behaviour 
{
  "name": "ajduke",
  "languagesKnown": [
    "Java",
    "Scala",
    "Ruby"
  ]
}
Including the nulls 

ajduke

Default behaviour 
{
  "name": "ajduke",
  "classz": "Developer",
  "languagesKnown": [
    "Java",
    "Scala",
    "Ruby"
  ]
}

ajduke

Gson gson = new Gson();

System.out.println("Default behaviour ");
GsonBuilder gsonBuilder = new GsonBuilder();
Gson prettyGson = gsonBuilder.setPrettyPrinting().create();
String json = prettyGson.toJson(new Developer());
System.out.println(json);

System.out.println("Ignoring/excluding fields ");

ajduke

Gson gson = new Gson();

System.out.println("Default behaviour ");
GsonBuilder gsonBuilder = new GsonBuilder();

Gson prettyGson = gsonBuilder.setPrettyPrinting().create();
String json = prettyGson.toJson(new Developer());
System.out.println(json);

System.out.println("Including the nulls ");

ajduke

class Developer {

  private String name;
  private String classz;
  List<String> languagesKnown;
  
  public Developer() {
    name = "ajduke";
    classz= "Developer";
    languagesKnown = new ArrayList<>();

ajduke

********* Compact mode ***********
{"name":"ajduke","languagesKnown":["Java","Scala","Ruby"]}

 ******* Pretty formatting *********
{
  "name": "ajduke",
  "languagesKnown": [
    "Java",
    "Scala",
    "Ruby"

ajduke

package in.ajduke.ap013;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.annotations.SerializedName;

ajduke

Gson gson = new Gson();
String json = gson.toJson(new Developer());
System.out.println("********* Compact mode ***********");
System.out.println(json);

GsonBuilder gsonBuilder = new GsonBuilder();
Gson prettyGson = gsonBuilder.setPrettyPrinting().create();
json = prettyGson.toJson(new Developer());
System.out.println("\n ******* Pretty formatting *********");
System.out.println(json);

ajduke

class Developer {

  private String name;
  private String classz;
  List<String> languagesKnown;
  
  public Developer() {
    name = "ajduke";
    languagesKnown = new ArrayList<>();
    languagesKnown.add("Java");

ajduke

Type collectionType = new TypeToken<{generic-object-with-type-information}>(){}.getType();