JSON to Java

JSON2Java.java

public class JSON2Java {
  
   private static final ScriptEngine jsonParser;
   
   static
   {
      try
      {
         String init = read(Tools.class.getResource("json2java.js"));
         ScriptEngine engine = new ScriptEngineManager().getEngineByName("JavaScript");
         engine.eval(init);
         jsonParser = engine;
      }
      catch (Exception e)
      {
         // Unexpected
         throw new AssertionError(e);
      }
   }

   public static Object parseJSON(String json)
   {
      try
      {
         String eval = "new java.util.concurrent.atomic.AtomicReference(toJava((" + json + ")))";
         AtomicReference ret = (AtomicReference)jsonParser.eval(eval);
         return ret.get();
      }
      catch (ScriptException e)
      {
         throw new RuntimeException("Invalid json", e);
      }
   }
}

json2java.js

toJava = function(o) {
  return o == null ? null : o.toJava();
};
Object.prototype.toJava = function() {
  var m = new java.util.HashMap();
  for (var key in this)
    if (this.hasOwnProperty(key))
      m.put(key, toJava(this[key]));
  return m;
};
Array.prototype.toJava = function() {
  var l = this.length;
  var a = new java.lang.reflect.Array.newInstance(java.lang.Object, l);
  for (var i = 0;i < l;i++)
    a[i] = toJava(this[i]);
  return a;
};
String.prototype.toJava = function() {
  return new java.lang.String(this);
};
Boolean.prototype.toJava = function() {
  return java.lang.Boolean.valueOf(this);
};
Number.prototype.toJava = function() {
  return java.lang.Integer(this);
};

parse

String eval = "new java.util.concurrent.atomic.AtomicReference(toJava((" + json + ")))";
AtomicReference ret = (AtomicReference)jsonParser.eval(eval);
return ret.get();

setup

String init = read(Tools.class.getResource("json2java.js"));
ScriptEngine engine = new ScriptEngineManager().getEngineByName("JavaScript");
engine.eval(init);
jsonParser = engine;