zoodubbo

A Javascript module for Node.js to connect Dubbo service by node-zookeeper-client.

Features

• Invoke Dubbo service as a Customer.
• Use Zookeeper as the Dubbo Registration Center.
• Only supports the use of the default hessian2 protocol for serialization and deserialization.
• It is not very friendly to support the return value containing an enum type.
• Use Random LoadBalance to choose Provider.
• Use generic-pool to manage net.Socket.

Installation

You can install it using npm:

$ npm install zoodubbo

Example

var ZD = require('zoodubbo');
var zd = new ZD({
    // config the addresses of zookeeper
    conn: 'localhost:2181'
});

// connect to zookeeper
zd.connect();

// get a invoker with a service path
var invoker = zd.getInvoker('com.demo.Service');

// excute a method with parameters
var method = 'getUserByID';
var arg1={$class:'int',$:123};
invoker.excute(method, [arg1], function (err, data) {
    if (err) {
        console.log(err);
        return;
    }
    console.log(data)
});

Documentation

new ZD(conf)

Arguments

• conf {String|Object} - A string of host:port pairs like conn. Or an object to set the instance options. Currently available options are:

  • dubbo {String} - Dubbo version information.

  The following content could reference: https://github.com/alexguan/node-zookeeper-client#client-createclientconnectionstring-options

  • conn {String} - Just like connectionString of node-zookeeper-client. Comma separated host:port pairs, each represents a ZooKeeper server.
  • sessionTimeout {Number} - Session timeout in milliseconds, defaults to 30 seconds.
  • spinDelay {Number} - The delay (in milliseconds) between each connection attempts.
  • retries {Number} - The number of retry attempts for connection loss exception.

Example

// use a string of host:port pairs
var zd = new ZD('localhost:2181,localhost:2182');

// use an object to set the instance options
var zd = new ZD({
    conn: 'localhost:2181,localhost:2182',
    dubbo: '2.5.3'
});

---

client

The client instance created by node-zookeeper-client. To listen event such as follows:

zd.client.on('connected', function connect() {
    console.log('zookeeper client connected!');
});

The list of events could reference: https://github.com/alexguan/node-zookeeper-client#state

---

void connect()

Connect to the Dubbo Registration Center by node-zookeeper-client. Equivalent to the following code:

zd.connect();
// just like
zd.client.connect();

---

void close()

Close the connection of node-zookeeper-client. Equivalent to the following code:

zd.close();
// just like
zd.client.close();

---

Invoker getInvoker(path[, opt])

Arguments

• path {String} - Path of service.

• opt {Object} - An object to set the Invoker options. Currently available options are:

  • version {String} - Service version information.
  • timeout {Number} - The timeout (in milliseconds) to excute.

  The following content could reference: generic-pool

  • poolMax {Number} - Maximum number of net.Socket to create from pool at any given time. Defaults to 1 .
  • poolMin {Number} - Minimum number of net.Socket to keep in pool at any given time. If this is set >= poolMax, the pool will silently set the min to equal max. Defaults to 0 .

Example

var invoker = zd.getInvoker('com.demo.Service', {
    version: '0.0.0'
});

---

new Invoker(zk[, opt])

Also you can create Invoker instance by URIs of providers directly.

Arguments

• zk {Client|String|Array} - The ZD instance or the URIs of providers.

• opt {Object} - An object to set the instance options. Currently available options are:

  • path {String} - Path of service.
  • dubbo {String} - Dubbo version information.

  The other content is same as the opt in getInvoker(path[, opt])

Example

var invoker = new ZD.Invoker(
  'dubbo://127.0.0.1:20880/com.demo.DemoService?interface=com.demo.DemoService&methods=sayHello',
  { version: '0.0.0' }
);

---

void excute(method, args[, cb])

Arguments

• method {String} - Method to excute.
• args {Array} - Argument list.
• cb(err, data) {Function} - The data is the returned value. When the cb is undefined, the function return a Promise instance.

Example

var method = 'getUserByID';
var arg1={$class:'int',$:123};

// use callback
invoker.excute(method, [arg1], function (err, data) {
    if (err) {
        console.log(err);
        return;
    }
    console.log(data)
});

// or return a Promise instance
invoker.excute(method, [arg1])
    .then(function(data){
        console.log(data);
    }).catch(function(err){
        console.log(err);
    });

---

License

Licensed under the MIT license.