I'm developing a Desktop LAN base java server and client application
where a Client must login and also to pass some data to server.
assuming i have 10 clients that inserting record simultaneously to server.
which is the best approach in this kind of situation, should I use RMI for login and record insertion? or Sockets?
if sockets please provide a key idea for me to start with.
key points to consider
-Multithreading
-able to send back data on client
If you want to connect your server via internet (and/or firewalls) it is probably a hassle to do this with plain RMI. In the past I have used Java Simon for such tasks which is very easy to implement. However if you plan to support other clients than Java clients, then you should have a look at Apache Thrift or Google Protocoll Buffers
Related
I am extending custom written windows based server (c#). Currently server provides two commnication interfaces (SignalR based, and simplified TCP protocol based). Both interfaces work well with windows clients which i also wrote.
There is a new requirement that server should communicate with native Android (java) client. Communication should be bi-directional:
-> server should be able to push data to client
-> client should be able to push data to sever
Can you recommend any usefull communication solution?
It Man.
Have you considered JSON over HTTP2?
In HTTP2 you can do a server push which allows bi-directional communication. That being said, often bi-direction communication between a client and server like this is implemented with a polling model.
Another option might be GRPC which allows streaming connections on top of http2. It often uses proto as the serialization format but doesn't have to.
Those two might be worth checking out.
I am having difficulties understanding the difference between network mode and non-network mode terms as used when dealing with client server applications in java.
I know how to develop simple client server apps. For example I can create a client application and server application. These applications can connect to through sockets and send and receive data. I however get confused when people talk about running a server and client in standalone mode, where both the client and server use the same instance of a JVM without loop back networking involved. I have seen this happening with the java derby database.
So my main question is how do you take code that was using sockets to communicate and convert it to use the so called "standalone mode" where the client and server run as one application? I will appreciate any comments that point me to the right material.
In the so-called network mode you have to connect to a remote server, as you describe, typically through a socket and so your client asks the server to do certain task, the server carries out the task and responds to the client.
In this mode, it is customary that the client and the server will be different nodes, that is different machines, running independently.
But what if you wanted to run you client and your server in the same machine? Even in the same virtual machine? Would it make sense to go through a socket to ask your server to do something?
That would be like using Skype to chat with a friend sat right by your side, to simply ask him to go have lunch.
So, ideally, in these cases, you should be able to run your application in non-network mode. That is, instead of going through a socket, you access your sever object directly and ask it to do something for you. Since your server object is located in the same virtual machine as your client.
Evidently, for you to be able to do this, you need a good design that exposes your server functionality through an interface, and your application uses this interface to interact with the server. When you are running in network mode, you use an implementation of this server interface that uses a socket (or RMI or whatever you do for network communication). When you are in non-network mode, you get an implementation of the server object itself.
I have a code running in router that sends UDP packets(using Sendto() function and a string of data) to a particular server whose IP address and port number I will mention in my code.
I want to deploy a server application that could receive a UDP packet and store its information on server or somewhere else not sure right now.
I have decided to use Google app Engine for hosting my server side code which most probably will be having something like recvfrom() function to receive string.
So how and by using what API's can I start developing my server side code.
Google App Engine has a Preview release of a Socket API, but it does not let you create listening sockets. See Limitations and restrictions section at https://developers.google.com/appengine/docs/python/sockets/
You cannot create a listen socket; you can only create outbound sockets.
You can use Google Compute Engine to run any reasonable software on Google's cloud platform, including programs that receive UDP datagrams. You must always pay for Compute Engine instances.
According to the newest edition of App Engine Socket docs for Java, if you're using java 8 runtime you should be able to use java sockets without limitations:
Applications in the Java 8 runtime default to using native Java
sockets with no restrictions: Google recommends that you keep this
default.
That means that it should be possible to use java.net.DatagramSocket or java.nio.channels.DatagramChannel freely to work with UDP.
I am developing system, that consists of client (written in JavaFX) and server. Now I am going to implement server. Users will download clients. Clients will communicate with server (only one server and many clients). Server will communicate with data base and send results. Server will support authentication and different requests (not http of course). Is it a good idea to implement server with Java RMI? If no, could you advice me any good idea about server realisation.
Thanks a lot for future questions!
RMI is bit kind of traditional but still powerful to me ,it has some draw back . But, despite the RMI there is also a chance for you to use java sockets class ? just like a client -server application ...
I have a java requirment contains both client and server side program.
Server side
Server program frequently check the data base and checks if a new order came, if order came it check the order and send it to the corresponding client machine using IP address and port.The client machines are out side the LAV and has static IP address.
Client side
Client program listen a its on port , when an order came, read it and process.
For implementing these app, which java package is best,java socket communication or any other.Anybody know please suggest one.
Help is highly appreciated,
Thanks,
vks.
Don't go for low level programming like Sockets etc. Use RMI. Your program will have following two entities
Server side :
An RMI Client for calling client machine to send update after checking the database
Client side :
An RMI server application listening for Server update requests and do processing.
If you are new to RMI check out this tutorial . You can search for better tutorials if don't find these good enough :).
I remember I had to do something similar in the university and I used JMS (Java Messaging Service), documented here:
http://www.oracle.com/technetwork/java/jms/index.html
The Server will create the messages from the DB by checking it periodically and will send messages to the clients which will process the info.