jetto is open source library to develop chat apps, real-time games, social media apps etc. for mobile devices.
jetto provides real-time bi-directional & secure communication. It creates TCP/IP based encrypted communication between server and clients.
Visit jetto official website
Server jetto library can be added to project from gradle and maven by adding below codes.
compile 'org.jetto:jetto-server:1.0.0'<dependency>
<groupId>org.jetto</groupId>
<artifactId>jetto-server</artifactId>
<version>1.0.0</version>
<type>pom</type>
</dependency>- Create a java application and add new java class
/**
*
* @author gorkemsari
*/
public class ServerApp {
public static void main(String[] args) {
}
}- Add ServerListener interface to class
- Abstract methods should be added onMessage, onStart, onStop, onError automatically depends on your IDE
- If not added, abstract methods should be defined with @Override annotation manually
import org.jetto.listener.ServerListener;
/**
*
* @author gorkemsari
*/
public class ServerApp implements ServerListener{
public static void main(String[] args) {
}
//message: client message
//id: client id
@Override
public void onMessage(String message, String id) {
//clients messages
}
//id: client id
@Override
public void onStart(String id) {
//new client connected and secure communication is started
}
//id: client id
@Override
public void onStop(String id) {
//client disconnected
}
//message: error message
//id: client id
@Override
public void onError(String message, String id) {
//some error occured during communication
}
}- Add new ServerEndpoint with defined port number
- Set listener to ServerEndpoint and start server
- Now server starts to wait connection requests from clients
- If any client connects to server, a random id is sent to client and new encryption key produced by Diffie-Hellman key exchange algorithm and secure communication is started between server and client. Aes encryption algorithm is used to encryption.
import org.jetto.endpoint.ServerEndpoint;
import org.jetto.listener.ServerListener;
/**
*
* @author gorkemsari
*/
public class ServerApp implements ServerListener{
static ServerEndpoint server;
static int port = 2329;
public static void main(String[] args) {
server = new ServerEndpoint(port);
server.setServerListener(new ServerApp());
server.start();
}
//message: client message
//id: client id
@Override
public void onMessage(String message, String id) {
//clients messages
System.out.println("new message from " + id + ". message:" + message);
}
//id: client id
@Override
public void onStart(String id) {
//new client connected and secure communication is started
System.out.println("new client connected: " + id);
}
//id: client id
@Override
public void onStop(String id) {
//client disconnected
System.out.println("client disconnected: " + id);
}
//message: error message
//id: client id
@Override
public void onError(String message, String id) {
//some error occured while any client's request is processing
System.out.println("error occured. message: " + message + "client: " + id);
}
}Models should be extended by Model class of jetto. Model class has type property for parsing processes.
import org.jetto.model.Model;
/**
*
* @author gorkemsari
*/
public class MessageModel extends Model {
private String header;
private String message;
/**
* @return the header
*/
public String getHeader() {
return header;
}
/**
* @param header the header to set
*/
public void setHeader(String header) {
this.header = header;
}
/**
* @return the message
*/
public String getMessage() {
return message;
}
/**
* @param message the message to set
*/
public void setMessage(String message) {
this.message = message;
}
}As mentioned above, models are extended by Model class of jetto. While setting models properties also type property of Model should be set. Models are parsed to json by toJson() method of Parser class. Parser uses gson library on background for parsing process.
import org.jetto.parser.Parser;
/**
*
* @author gorkemsari
*/
MessageModel messageModel = new MessageModel();
messageModel.setHeader("This is header");
messageModel.setMessage("Hello from server!");
messageModel.setType(1);//setType is extended from Model class of jetto
Parser parser = new Parser();//parser class of jetto
String json = parser.toJson(messageModel);The message type can be retrieved by getType() method of Parser when a json message is received. Json messages are parsed to related model by toModel() method of Parser class according to type.
import org.jetto.parser.Parser;
/**
*
* @author gorkemsari
*/
String json = "{
"header": "This is header",
"message": "Hello from server!",
"type": "1"
}";
Parser parser = new Parser();//parser class of jetto
int type = parser.getType(json);
switch (type) {
case 1:
MessageModel messageModel = parser.toModel(json, MessageModel.class);
...
break;
case 2:
OtherModel otherModel = parser.toModel(json, OtherModel.class);
...
break;
default:
...
break;
}jetto sends all messages as byte array on background. Any format of string or json can be selected on high level usage. All messages will be caught on the onMessage method of clients.
id is produced by server at begining of connection process and sent to client to define it as unique.
String id = "5345ud-9ur6j-dfg34-3e82gb";//client id
server.write("Hello from server!", id);Define a client id list.
List<String> idList = new ArrayList<>();
idList.add("5345ud-9ur6j-dfg34-3e82gb");//client id
idList.add("e4t56-l9k2nb-0iplm-441e7y");//client id
idList.add("8yfd5s-33vbn6-27y5r-r5fxm");//client id
server.write("Hello from server!", idList);server.write("Hello from server!");String id = "5345ud-9ur6j-dfg34-3e82gb";//client id
MessageModel messageModel = new MessageModel();
messageModel.setHeader("This is header");
messageModel.setMessage("Hello from server!");
messageModel.setType(1);//setType is extended from Model class or jetto
Parser parser = new Parser();//parser class of jetto
server.write(parser.toJson(messageModel), id);List<String> idList = new ArrayList<>();
idList.add("5345ud-9ur6j-dfg34-3e82gb");//client id
idList.add("e4t56-l9k2nb-0iplm-441e7y");//client id
idList.add("8yfd5s-33vbn6-27y5r-r5fxm");//client id
MessageModel messageModel = new MessageModel();
messageModel.setHeader("This is header");
messageModel.setMessage("Hello from server!");
messageModel.setType(1);//setType is extended from Model class or jetto
Parser parser = new Parser();//parser class of jetto
server.write(parser.toJson(messageModel), idList);MessageModel messageModel = new MessageModel();
messageModel.setHeader("This is header");
messageModel.setMessage("Hello from server!");
messageModel.setType(1);//setType is extended from Model class or jetto
Parser parser = new Parser();//parser class of jetto
server.write(parser.toJson(messageModel));jetto receives all messages as byte array on background. All messages will be caught on the onMessage method of server with sender client's id.
import org.jetto.parser.Parser;
/**
*
* @author gorkemsari
*/
@Override
public void onMessage(String message, String id) {
Parser parser = new Parser();//parser class of jetto
int type = parser.getType(message);
switch (type) {
case 1:
MessageModel messageModel = parser.toModel(message, MessageModel.class);
...
break;
case 2:
OtherModel otherModel = parser.toModel(message, OtherModel.class);
...
break;
default:
...
break;
}
}