Pretty Prints JSON using Java.

prettyPrintJson.java

import java.io.*;
import java.util.*;

public class JSONPetty {

    public static void main(String[] args) {
         String myJsObj = "['foo', {'bar':['baz',null,1.0,2]}]";

        System.out.println(prettyPrint(myJsObj));
    }
    public static String prettyPrint(String JSON){
        String result = "";
        int indent = 0;
        for(char c : JSON.toCharArray()){
            if(c == '{' || c == '['){
                result+="\n";
                for(int i = 0; i<indent; i++){
                    result+="  ";
                }
                result += c;
                indent++;
                result+="\n";
                for(int i = 0; i<indent; i++){
                    result+="  ";
                }
            }else if(c == ','){
                result+=c;
                result+="\n";
                for(int i = 0; i<indent; i++){
                    result+="  ";
                }
            }else if(c=='}' || c==']'){
                result+="\n";
                indent--;
                for(int i = 0; i<indent; i++){
                    result+="  ";
                }
                result+=c;
            }else{
                result+= c;
            }
        }
        return result;
    }
    
}


/*
Output : 
[
  'foo',
   
  {
    'bar':
    [
      'baz',
      null,
      1.0,
      2
    ]
  }
]
*/