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I’ve made a significant performance improvement to org.json – Java package maintained by Douglas Crockford. It’s the Java reference implementation officially improved by json.org.

Here is where Douglas committed my changes


2312 days ago

I’ve just finished the most complete and advanced (i’m modest;) JavaScript JSON-RCP 2.0 client.

It is called ‘Do It! JSON-RPC’ or ‘dijr’ in short. And here is some usage information:

Setting up

To use dijr you need two additional libraries:

  • jQuery
  • JSON2.js

Basically to enable dijr for your web application you should add something like that in the section:

<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>
<script type="text/javascript" src="https://raw.github.com/douglascrockford/JSON-js/master/json2.js"></script>
<script type="text/javascript" src="dijr.js"></script>


When the page is loaded you should initialize dijr. The best way to do that is on page load, so in JavaScript code it would look like:

var remote = false; // this is dijr, not initialized yet
$(function() {
  remote = dijr('/remote/json-rpc');

The code above will initialize dijr on page load, and will create an object that will use ‘/remote/json-rpc’ as url to the JSON-RPC server.

Calling remote method

Calling a remote method is simple but yet powerful. The remote call can be asynchronous or synchronous.

To illustrate the both ways, we will use as example the following remote method:

myModule.method(boolean param1, int param2, String param3)


To call the remote method above in synchronous way, you should use dijr this way:

var response = remote.call('myModule.method', true, 2, 'abc')

Note, that synchronous mode will send the HTTP request, wait for it’s completion and return the parsed JSON-RPC response immediately. But if you do a lot of calls, this method is slow because it waits for completion .


To optimize the performance of your web application you’d better use asynchronous calls. To call the example method in asynchronous mode your code should look like this:

remote.call('myModule.method', true, 2, 'abc', function(response, jqXHR) {

Note that in asynchronous mode you don’t have a return value but instead you use a callback method to receive the response.

The callback method receives 2 parameters:

  • parameter 1 – JSON object containing the parsed JSON-RCP response
  • parameter 2 – jqXHR provides direct access to the XMLHttpRequest.

Calling remote methods (multicall)

This JSON-RCP library supports ‘multicall’ specification. This means that you can invoke multiple JSON-RPC methods just with one call.

Let’s assume that you have a second remote method:

myModule.sayHello(String message)

To invoke the two remote methods in one call you can use something like that:

var response = remote.multicall({
  'myModule.method' : [ true, 2, 'abc' ],
  'myModule.sayHello': [ 'hello world' 
var method1Response = response[0];
var method2Response = response[1];

The same thing, but done asynchronously will look the way below:

    'myModule.method' : [ true, 2, 'abc' ],
    'myModule.sayHello': [ 'hello world' 
  function(response,jqXHR) {
    var method1Response = response[0];
    var method2Response = response[1];

Using method wrappers

During initialization, dijr will try to make a single synchronous call to invoke one special JSON-RPC function named ‘system.listMethods’. If that function is available in the system, dijr will create automatic wrappers for the methods returned by the function.

So if ‘system.listMethods’ returns [‘myModule.method’,‘myModule.sayHello’], you can use also the following construction for sync and async calls:

// call synchronously
var response = remote.myModule_method(false, 1000000, 'apples');
// call asynchronously
remote.myModule_method(true, 10, 'cherries', function(response) {
  // handle response


Finally after you read the documentation, you can download dijr.js and dijr.min.js and start Doing It!.