#This JSON library for java is a fork from in Java [package org.json] Douglas Crockford

The key changes are: ##JSONObject is extended from LinkedHashMap ##

• Ensures order of elements
• Enables the normal HashMap methods to be available although most of them were overridden in earlier implementation like keys() and keySet()
• Main reason to do this is to enable libraries which works on HashMap and ArrayLists to be able to work on JSONObject
• json-lib project implements Map which is probably an even better approach. But it also gets the same benefits as above point.

Known Issue: *In JDK7 The order of elements serialized from a bean or local ResourceBundle provided through a class will not maintian the order of elements in JSONObject. This is because in JDK 7 getDeclaredMethods() does not retrieve the methods in order it is random and can vary from time to time. A bug was logged for jdk but was rejected as wont fix. In JDK6 and lower versions the order is maintained however this is a feature not mentioned in specifications of jdk.

##JSONArray extends from ArrayList##

• This in combination with JSONObjects extends from LinkedHashMap enables the whole library to be usable in a generic way where other libraries which uses model data in any combination of Map<String, Object> and List for example Map<String,List>.

  ##XML to JSON Serialization##

  • Attributes are marked with a '@' prepended to the key
  • Content element is marked with a '#' prepended to the key
  • Since the json keeps order of the original xml elements it can be deserialized back to same xml.

  An xml of format

  <root><person fname="samarjit" lname="samanta" >normal text</person></root>
  

  will serialize to

  {"root":{"person":{"@fname":"samarjit","@lname":"samanta","#content":"normal text"}}}
  

  In earlier version it used to serialize to

  {"root":{"person":{"fname":"samarjit","lname":"samanta","content":"normal text"}}}	
  

  ##JSON to XML Serialization##

  Since we have the attribute marked in the json, we can create back the exact xml if input xml is

  {"root":{"person":{"@fname":"samarjit","@lname":"samanta","#content":"normal text"}}}
  

  this will produce

  <root><person fname="samarjit" lname="samanta">normal text</person></root>
  

  old version of JSON eg. release version 20090211 or before will produce

  Since the json produced is
  {"root":{"person":{"content":"normal text","lname":"samanta","fname":"samarjit"}}} It will produce normal textsamantasamarjit

  Example of libraries that uses model as combination of Map<String,Object> and List and arbitrary java beans.

  Freemarker

  	String templateExpression = "Hi ${ddd} hello ${ar[0]} your home is ${USER_HOME}";
  
  	Template t = new Template("name", new StringReader(templateExpression), new Configuration());
  	StringWriter out = new StringWriter();
  	
  	JSONObject jobj1 = new JSONObject();
  	jobj1.put("ddd","jsss");
  	JSONArray ar =  new JSONArray("['jhaldia','jdob']");
  	jobj1.put("ar", ar);
  	jobj1.put("USER_HOME", System.getProperty("user.home").replace("\\","/"));
  		
  	t.process(jobj1, out );
  	
  	String ret = out.toString(); 
  	
  	System.out.println(ret);
  

  Result This version produces Hi jsss hello jhaldia your home is C:/Users/Samarjit

  Earlier version json: Hi jsss hello [ your home is C:/Users/Samarjit

  Ognl

  	JSONObject jobj1 = new JSONObject();
  	jobj1.put("ddd","jsss");
  	JSONArray ar =  new JSONArray("['jhaldia','jdob']");
  	jobj1.put("ar", ar);
  	System.out.println(Ognl.getValue("ar[0]", rootObject , jobj1 ));	
  	Object obj2 =  Ognl.getValue("someBean.sss",context);
  	System.out.println(obj2);
  

  Result This version produces jhaldia dddd

  Earlier version json ognl.NoSuchPropertyException: org.json.JSONObject.ar

  Please refer to the original README for other functions.