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How to use socket to communicate between client and server in Java? aiming at this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

Network programming in Java is a very important part, and it is also one of its programming advantages. There is a special Java.net class library in Java to manage the methods of network programming.

Let's first describe how to use socket to communicate between client and server in Java. Finally, we will introduce one of the simplest telephone programs.

one。 How to use socket to communicate between client and server

Socket is used to program the communication between client and server in Java. Socket is an effective endpoint for communication between two entities. The source IP address and source port, the end IP address and the end port can be obtained through socket. Users can connect multiple socket to the same port so that there can be multiple connections for a single port. Through socket client / server programming, you can create a distributed program that can be used by many people, and all clients can work with a unified front end and communicate with the server.

To communicate with the server, you must have three conditions: the server program, the client program, and the socket program that connects them. None of these three parts is indispensable. However, there are many ways to communicate between the client and the server, one of which is to take the client as the taker and the server as the giver. Let's take a look at Java's server programming.

In Java, the server has three main functions:

1. By constructing an instance of the ServerSocket class in the Java.net class library, the server can detect the information of the specified port. The accept () method in ServerSocke enables the server to detect activity on the specified port. In addition, the server is responsible for detecting customers who are required to connect to it.

An instance of the Socket class represents a successful connection between the client and the server. Multiple users can be programmatically connected to the server through the same port, all of which are instances of the Socket class.

two。 You can send and capture data using the getInputStream () and getOutStream () methods of the Socket class, respectively. The method of use is as follows:

Try {

ServerSocket myServerSocket=new ServerSocket (100)

Socket my100Socket=myServerSocket.accept ()

} catch (Exception e) {}

In the above code, you first construct an instance of the ServerSocket class and pass it an integer to specify a given port that can be used by the server, as follows:

ServerSocket myServerSocket=new ServerSocket (100)

In the Java program, if you can keep catching abnormal events every time you construct a ServerSocket, you specify the port you are going to use at any time. The following code uses the accept () method to detect port activity.

Socket my100Socket=myServerSocket.accept ()

The Accept () method does not continue to execute the interrupted execution program until it receives a connection request from the user. Once the customer's connection is successful, my100Socket represents the connection and can send and receive data.

Finally, let's take a look at how the customer requests a connection. The connection method is as follows:

Try {

Socket mySocket=new Socket (www.cpcw.com, 100)

} catch (Exception e) {}

As you can see from the above code, it is also implemented through the Socket class. Let's use an example of network programming to illustrate how to communicate on the network.

two。 One of the simplest call programs

Communicator server:

Import java.net.*

Import java.io.*

Import java.lang.*

Public class myserver {

Public static void main (String args []) {

ServerSocket server

Socket socket

String s

InputStream Is

OutputStream Os

DataInputStream DIS

PrintStream PS

Try {

/ / Register the service on port 4321

Server=new ServerSocket (4321)

Socket=server.accept (); / / listening window, waiting for connection

System.out.println ("server ok")

System.out.println ("* *")

System.out.println ("")

/ / get the input / output stream of the corresponding Socket

Is=socket.getInputStream ()

Os=socket.getOutputStream ()

/ / establish data flow

DIS=new DataInputStream (Is)

PS=new PrintStream (Os)

DataInputStream in=new DataInputStream (System.in)

While (true) {

System.out.println ("")

System.out.println ("please wait client's message...")

System.out.println ("")

S=DIS.readLine (); / / read in the string from client

System.out.println ("client said:" + s); / / print string

If (s.trim () .equals ("BYE") break; / / if it is "BYE", quit

System.out.print ("you say:")

S=in.readLine (); / / read the string entered by the user

PS.println (s); / / pass the read string to client

If (s.trim () .equals ("BYE") break; / / if it is "BYE", quit

}

/ / close the connection

DIS.close (); / / close the data input stream

PS.close (); / / close the data output stream

Is.close (); / / close the input stream

Os.close (); / / close the output stream

Socket.close (); / / close sockey

}

Catch (Exception e) {

System.out.println ("Error:" + e)

}

}

}

Intercom client

Import java.net.*

Import java.io.*

Import java.lang.*

Public class myclient {

Public static void main (String args []) {

If (args.length

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