samarjit/JSON-java: A reference implementation of a JSON package in Java. · GitHub

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

##Version 20121208 I finally made these changes, no reason for not having done before.

• JSONObject implements Map
• JSONArray implements List
• Added separate tests for Ognl and Freemarker. Yet to include them in regression test.

##Version 20121205 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.
  • Type inference is removed, every value is treated as string

  Earlier version of JSON below refers to release version 20090211 or before.

  XML to JSON to XML conversion

  	//This version 20121205 on wards 
  	<root><person fname="samarjit" lname="samanta" >normal text</person><version>1.0</version></root>
  	
  	//This version XML -> JSON 
  	{"root":{"person":{"@fname":"samarjit","@lname":"samanta","#content":"normal text"},"version":"1.0"}}
  	//This version JSON -> XML	
  	<root><person fname="samarjit" lname="samanta">normal text</person><version>1.0</version></root>
  
  			
  	//## Earlier version json ##
  	<root><person fname="samarjit" lname="samanta" >normal text</person><version>1.0</version></root>
  	//Earlier version XML->JSON
  	{"root":{"person":{"content":"normal text","lname":"samanta","fname":"samarjit"},"version":1}}
    	//Earlier version JSON-> XML
    	<root><person>normal text<lname>samanta</lname><fname>samarjit</fname></person><version>1.0</version></root>
    	

  ####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);
          assertEquals("Hi jsss hello jhaldia your home is "+System.getProperty("user.home").replace("\\","/"),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

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