JsonToString in GWT

import java.util.Iterator;

import com.google.gwt.json.client.*;

/**
 * 
 * try to analyse the json data,
 * reference:   http://www.cnblogs.com/liubiqu/archive/2008/04/22/1164788.html
 *
 */
public class Parser {
     public static String json2String(JSONValue json){
    	 String result = "";
    	 if( json == null) {
    		 return "(null): invalid data";
    	 }
    	 
    	 if(json.isObject() != null) {
    		 //case 'object'
    		 if(json.isObject().isArray() != null) {
    			 //case 'array'
                 //members of object
                 //reference: http://www.json.org/
//    			 members
// 			        pair , members
    			 for(int item = 0; item < json.isObject().isArray().size(); item++) {
    				 result += json2String(json.isObject().isArray().get(item));
    				 result += "," ;
    			 }
    			 
    			 return "[" + result.substring(0, result.length()-1) + "]";
    		 }
    		 else {
    			 //members of object 
    			 //reference: http://www.json.org/
//    			 members
//    			    pair
    			 for(Iterator properties = json.isObject().keySet().iterator(); properties.hasNext(); ) {
    				 String property =  properties.next().toString();
    				 JSONValue value = json.isObject().get(property);
    				 result += "\"" + property + "\":" + json2String(value); 
    				 result += ",";
    			 }
    			 
    			 return "{" + result.substring(0, result.length()-1) + "}";
    		 }
    	 }
    	 else if (json.isString() != null) {
    		 //case 'string'
    		 return json.isString().stringValue();
    	 }
    	 else if (json.isNull() != null) {
    		//case  'null'
    		 return "null";
    	 }else {
    		 return "\"" + json.toString()  + "\"" ;
    	 }
    	 
    	 
     }
}