Java and Android Socketcluster Client
Overview
This client provides following functionality
- Support for emitting and listening to remote events
- Automatic reconnection
- Pub/sub
- Authentication (JWT)
License
Apache License, Version 2.0
Gradle
For java
compile 'io.github.sac:SocketclusterClientJava:2.0.0'
}
for sample java examples visit Java Demo
For android
exclude group :'org.json', module: 'json'
}
for sample android demo visit Android Demo
- In case you face any problem while resolving dependencies, you can download jar from here https://dl.bintray.com/sacoo7/Maven/io/github/sac/SocketclusterClientJava/.
- Please report for the issue here #36
Description
Create instance of Socket class by passing url of socketcluster-server end-point
String url="ws://localhost:8000/socketcluster/";
Socket socket = new Socket(url);
Important Note : Default url to socketcluster end-point is always ws://somedomainname.com/socketcluster/.
Registering basic listeners
Implemented using BasicListener interface
public void onConnected(Socket socket,Map<String, List<String>> headers) {
System.out.println("Connected to endpoint");
}
public void onDisconnected(Socket socket,WebSocketFrame serverCloseFrame, WebSocketFrame clientCloseFrame, boolean closedByServer) {
System.out.println("Disconnected from end-point");
}
public void onConnectError(Socket socket,WebSocketException exception) {
System.out.println("Got connect error "+ exception);
}
public void onSetAuthToken(String token, Socket socket) {
System.out.println("Token is "+ token);
}
public void onAuthentication(Socket socket,Boolean status) {
if (status) {
System.out.println("socket is authenticated");
} else {
System.out.println("Authentication is required (optional)");
}
}
});
Connecting to server
- For connecting to server:
socket.connect();
- For connecting asynchronously to server:
socket.connectAsync();
- By default reconnection to server is not enabled , to enable it :
socket.setReconnection(new ReconnectStrategy().setDelay(2000).setMaxAttempts(30));
socket.connect();
- To disable reconnection :
socket.setReconnection(null);
- By default logging of messages is enabled ,to disable :
socket.disableLogging();
Emitting and listening to events
Event emitter
- eventname is name of event and message can be String, boolean, Long or JSON-object
//socket.emit("chat","Hi");
- To send event with acknowledgement
public void call(String eventName,Object error, Object data) {
//If error and data is String
System.out.println("Got message for :"+eventName+" error is :"+error+" data is :"+data);
}
});
Event Listener
- For listening to events :
The object received can be String, Boolean, Long or JSONObject.
public void call(String eventName,Object object) {
// Cast object to its proper datatype
System.out.println("Got message for :"+eventName+" data is :"+data);
}
});
- To send acknowledgement back to server
public void call(String eventName,Object object, Ack ack) {
// Cast object to its proper datatype
System.out.println("Got message :: " + object);
/...
Some logic goes here
.../
if (error){
ack.call(eventName,error,null);
}else{
//Data can be of any data type
ack.call(eventName,null,data);
}
//Both error and data can be sent to server
ack.call(eventName,error,data);
}
});
Implementing Pub-Sub via channels
Creating channel
- For creating and subscribing to channels:
//Socket.Channel channel = socket.createChannel("yolo");
/**
* without acknowledgement
*/
channel.subscribe();
/**
* with acknowledgement
*/
channel.subscribe(new Ack() {
public void call(String channelName, Object error, Object data) {
if (error == null) {
System.out.println("Subscribed to channel "+channelName+" successfully");
}
}
});
- For getting list of created channels :
- To get channel by name :
//Returns null if channel of given name is not present
Publishing event on channel
- For publishing event :
/**
* without acknowledgement
*/
channel.publish(message);
/**
* with acknowledgement
*/
channel.publish(message, new Ack() {
public void call(String channelName,Object error, Object data) {
if (error == null) {
System.out.println("Published message to channel "+channelName+" successfully");
}
}
});
Listening to channel
- For listening to channel event :
public void call(String channelName , Object object) {
System.out.println("Got message for channel "+channelName+" data is "+data);
}
});
Un-subscribing to channel
* without acknowledgement
*/
channel.unsubscribe();
/**
* with acknowledgement
*/
channel.unsubscribe(new Ack() {
public void call(String channelName, Object error, Object data) {
if (error == null) {
System.out.println("channel unsubscribed successfully");
}
}
});
Handling logging
- Once logger object is received, it is very easy to set internal logging level of library, applying handler for each log messages.
- It can be received using following code
- More documentation on handling logging in custom way can be found here http://www.vogella.com/tutorials/Logging/article.html
Handling SSL connection with server
WebSocketFactory class is responsible for creating websocket instances and handling settings with server, for more
information visit here
To get instance of WebSocketFactory class :
WebSocketFactory factory=socket.getFactorySettings();
The following is an example to set a custom SSL context to a WebSocketFactory
instance. (Again, you don't have to call a setSSL* method if you use the default
SSL configuration.)
SSLContext context = NaiveSSLContext.getInstance("TLS");
// Set the custom SSL context.
factory.setSSLContext(context);
NaiveSSLContext
used in the above example is a factory class to create an SSLContext which
naively accepts all certificates without verification. It's enough for testing
purposes. When you see an error message "unable to find valid certificate path
to requested target" while testing, try NaiveSSLContext.
Setting HTTP proxy with server
If a WebSocket endpoint needs to be accessed via an HTTP proxy, information
about the proxy server has to be set to a WebSocketFactory instance before
creating a WebSocket instance. Proxy settings are represented by
ProxySettings class. A WebSocketFactory instance has an associated
ProxySettings instance and it can be obtained by calling
WebSocketFactory.getProxySettings() method.
ProxySettings settings = factory.getProxySettings();
ProxySettings class has methods to set information about a proxy server such
as setHost method and setPort method. The following is an example to set a
secure (https) proxy server.
settings.setServer("https://proxy.example.com");
If credentials are required for authentication at a proxy server, setId
method and setPassword method, or setCredentials method can be used to set
the credentials. Note that, however, the current implementation supports only
Basic Authentication.
settings.setCredentials(id, password);