JSON Accumulate 

JSON-lib is a java library for serializing and de-serializing java beans, maps, arrays and collections in JSON format. Get the latest binaries from sourceforge http://json-lib.sourceforge.net/. This requires the libraries ( json-lib-2.4-jdk15.jar, xom-1.2.7.jar, ezmorph.jar commons-lang.jar, commons-collections.jar, commons-beanutils-1.7.jar and commons-logging-1.1.1.jar) to be in classpath. The following example shows using accumulate method of JSONObject. It accumulates the values under a key. If we put multiple values for the same key, it replaces the value with a JSONArray containing all values.

File Name  :   com/bethecoder/tutorials/json_lib/tests/JsonAccumulate.java  Author  :   Sudhakar KV Email  :   [email protected]

package com.bethecoder.tutorials.json_lib.tests; import net.sf.json.JSONObject; public class JsonAccumulate {   /**    * @param args    */   public static void main(String[] args) {     JSONObject jsonObj = new JSONObject();     jsonObj.accumulate("certificates", "SCJA");     System.out.println(jsonObj.toString(2));          jsonObj.accumulate("certificates", "SCJP");     jsonObj.accumulate("certificates", "SCWCD");     System.out.println(jsonObj.toString(2)); //pretty print with indent   } }

{"certificates": "SCJA"}

{"certificates": [
  "SCJA",
  "SCJP",
  "SCWCD"
]}