Framework for JAVA socket server application - java

I'm developing an Android app using a server side for computations and message handling. I need to work with push notifications, so I decided to go with Socket and ServerSocket.
For now, my server side is just a pure JAVA code that receive requests and open sockets accordingly. Is there any framework for my purpose? And how should I run my server side app on a remote server, should I create a runnable jar or is there any other way?

You can use Apache MINA, which is a socket framework with useful features like NIO, session management, SSL and other filter support.
Using a reliable framework means you spend less time writing boilerplate code.
Yes, you can create a runnable jar and create a bat/sh script to run on your server. Read this article for more information on packaging applications.

Related

Communication between Java Swing Application(On client side) and server

What are the possible ways in which Java Swing Application which is running on client side can communicate with server?
I've read that JSP can be used in web pages to communicate between server and client.But, is it possible to use JSP with Swing application? if so, how? It would be helpful, if it is demonstrated with simple login form. Thanks.
Any client-side application, whether it be a java swing app or otherwise, can certainly communicate with any server (assuming no network limiting architecture -- firewalls and whatnot). Your options are numerous
Raw sockets
Any one of the myriad of network protocols.
HTTP/HTTPS
FTP
SCP
et. al.
It depends on what protocol, services and applications are available on the server to connect with.
HTTP/HTTPS is very common. You'll need to manually create HTTP requests and send them to the server (assuming the server is a web server).

Separated websocket for each connected client

I am planing to develop JavaScript client application that will connect to Java server using websocket. Server should handle many connected clients.
After some reading I found out websocket single thread. This is not good if I want to run databases query that can block everything for a while.
What I am thinking about is to opening separated websocket for each JavaScript client. One socket is listening for new connection and when connection is established creates some unique id. After that opens new websocket and send id to client using listener socket. When client received id close first socket and connect to new one.
What do you think, is it good solution? Maybe I am missing something?
Spring 4 gives you the chance to use a thread pool. The documentation is here:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/websocket.html
You could use Akka to manage all the concurrency and thread management for you. Or you could use the Play Framework that already builds on Akka and that supports WebSocket quite nicely. With Play you can choose between Java and Scala on the server side.
You should use NodeJS on the server to handle the socket i/o. You can connect to it via your javascript client apps, and then make calls to your Java based API. NodeJS is non blocking (async) and you should be able to leverage your existing Javascripting skills to quickly build a Node app. You could even use a full MEAN stack to build the client/server app. http://meanjs.org/ or http://mean.io/#!/ are two popular places to start.

Porting java sockets client to HTML5 socket.io

I have a multi-player game that uses Java sockets, the server is a standard Java application and the client is a Java applet that runs in the web-browser.
Now since last Java's update (Java 7 update 51) all applets require code signing, so I would like to move way from the applet and rewrite the client in HTML5.
I've been looking into the socket.io and it seems quite easy, but I can't find any information on how to implement it into my server.
I would like to keep the server in Java, because it will be a lot of work to port it, so is there any libs that I could use on my server to make the communication possible between a java sockets server and a socket.io client, or what is the best approach? do I really need to port the entirely server?
Thanks.
The html5 WebSocket on which socket.io works is not equal to a "normal" C or Java socket. It implements its own protocol over TCP which includes handshakes and other stuff. To port your server you have to use a library maybe this helps you.
For more information on the WebSocket protocol see here.

How to configure java server based on sockets (non http ) with Tomcat

I'm currently developing a web server based on sockets for a web game.
The client will be based on Java applet.
Is it possible to use Apache Tomcat server for this mission?
If it is possible, could you recommend us a step by step guide for how to configure it?
Do you think that we should use alternative server for that?
Will it be easier to implement this using servlets (http requests) and Google Application Engine?
I think you have to write your own connector and protocol handler for tomcat if you need another protocol than http.
In this case try Apache Mina.
I don't know anything about Servlets and Tomcat, but you can simply start the server as a standalone Java program, opening a ServerSocket to listen on the port. On each connection, split off a new Thread with will read from the new Connection.
For greater scalability, use nonblocking IO and a selector instead of a separate thread for each connection.

Message to a client from the server

I have to design a client/server system emulated on a website running Ruby on Rails that should work like this:
a page is requested by a web browser and once it's opened the server can push messages to it
I know this is not possible "naturally" but I was thinking of a sort of "java applet" that is running on that page, listening on a port for messages to be sent by the hosting server. This should be done opening a sort of a socket that listens on some port where the server can connect to send its messages.
Can this be done? Do I have to develop a java server thread or can I simply address the client applet via it's ip address and port and use any web service connection from the server?
thanks,
Luca
Comet is definately what you want. Depending on your needs, you can host your own comet server, or use a SaaS solution, such as WebSync On-Demand (disclaimer: I work there). Using the SaaS stuff, you get server-push capabilities without having to actually run your own comet server.
The easiest way to do that is to use Javascript to emulate the push mechanism. Polling in regular intervals using AJAX is sufficient in most cases. Have also a look at Comet.
An alternative to using a java applet may be to use a combination of javascript and an approach known as Comet. In a nutshell, Comet is a way to enable server push over HTTP. I'm not really a ruby on rails guy, but a quick google search for ruby on rails and comet nets a fair amount of useful information.
have you looked at juggernaut
If you want go the applet route, you need to make the connection from applet to the same server where the web page is served. The applet can't listen. Once the TCP connection is established, it's a 2-way channel, you can pull or push as long as your protocol allows it. This is how it's done with most Applet-based chat clients.
More and more people are simply using long polling in Javascript. It's pretty involved to get a reliable long polling system running, I would suggest you to use a framework. For example,
http://cometdproject.dojotoolkit.org/

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