Java 关于Socket

来源：互联网发布：mac桌面文件编辑：程序博客网时间：2024/06/16 22:49

Java Socket主要有普通Socket和NioSocket

普通Socket又分为 ServerSocket和Socket两种，ServerSocket用于服务端，通过accept方法监听请求，然后返回给Socket。
客户端直接用Socket发起请求并传输数据。

Clinet

import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;public class Client{    public static void main(String[] args) {        String msg = "Client Data";        try {            Socket socket = new Socket("127.0.0.1",10000);            PrintWriter pw = new PrintWriter(socket.getOutputStream());            BufferedReader is = new BufferedReader(new InputStreamReader(socket.getInputStream()));            pw.println(msg);            pw.flush();            String line = is.readLine();            System.out.println("received from Server: " + line);            pw.close();            is.close();            socket.close();        } catch (Exception e) {            // TODO: handle exception        }    }}

Server

import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.ServerSocket;import java.net.Socket;public class Server{    public static void main(String args[]){        try {            ServerSocket server = new ServerSocket(10000);            Socket socket  = server.accept();            BufferedReader is = new BufferedReader(new InputStreamReader(socket.getInputStream()));            String line = is.readLine();            System.out.println("receive:"+line);            PrintWriter pw = new PrintWriter(socket.getOutputStream());            pw.println("received data:"+line);            pw.flush();            pw.close();            is.close();            socket.close();            server.close();        } catch (Exception e) {            // TODO: handle exception        }    }}

java.nio包是Java在1.4之后增加的，用来提高I/O操作的效率。在nio包中主要包括以下几个类或接口:

Buffer：缓冲区，用来临时存放输入或输出数据。
Charset：用来把Unicode字符编码和其它字符编码互转。
Channel：数据传输通道，用来把Buffer中的数据写入到数据源，或者把数据源中的数据读入到Buffer。
Selector：用来支持异步I/O操作，也叫非阻塞I/O操作。

nio包中主要通过下面两个方面来提高I/O操作效率:

通过Buffer和Channel来提高I/O操作的速度。
通过Selector来支持非阻塞I/O操作。

import java.io.IOException;import java.net.InetSocketAddress;import java.net.ServerSocket;import java.net.SocketAddress;import java.net.SocketOption;import java.nio.ByteBuffer;import java.nio.channels.SelectableChannel;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.nio.charset.Charset;import java.util.Iterator;import java.util.Set;import java.util.logging.Handler;public class NIOSocket {    public static void main(String[] args) throws Exception {        //创建SeverSocketChannel，监听8080        ServerSocketChannel ssc =  ServerSocketChannel.open();        ssc.socket().bind(new InetSocketAddress(8080));        //设置非阻塞        ssc.configureBlocking(false);        Selector selector = Selector.open();        ssc.register(selector, SelectionKey.OP_ACCEPT);        Handler handler = new Handler(1024);        while(true){            if(selector.select(3000) == 0){                System.out.println("等待连接超时。。");                continue;            }            System.out.println("处理请求。。");            Iterator<SelectionKey> keyIter = selector.selectedKeys().iterator();            while(keyIter.hasNext()){                SelectionKey key = keyIter.next();                try {                    if(key.isAcceptable()){                        handler.handleAccept(key);                    }                    if(key.isReadable()){                        handler.handleRead(key);                    }                } catch (Exception e) {                    // TODO: handle exception                }                keyIter.remove();            }        }    }    private static class Handler{        private int bufferSize = 1024;        private String localCharset = "utf-8";        public Handler(){}        public Handler(int bufferSize){            this(bufferSize,null);        }        public Handler(String LocalCharset){            this(-1,LocalCharset);        }        public Handler(int bufferSize,String localCharset){            if(bufferSize > 0)                this.bufferSize = bufferSize;            if(localCharset != null)                this.localCharset = localCharset;        }        public void handleAccept(SelectionKey key)throws IOException{            SocketChannel sc = ((ServerSocketChannel)key.channel()).accept();            sc.configureBlocking(false);            sc.register(key.selector(), SelectionKey.OP_READ, ByteBuffer.allocate(bufferSize));        }        public void handleRead(SelectionKey key)throws IOException{            SocketChannel sc = (SocketChannel)key.channel();            ByteBuffer buffer = (ByteBuffer)key.attachment();            buffer.clear();            if(sc.read(buffer) == -1){                sc.close();            }else{                buffer.flip();                String receivedString = Charset.forName(localCharset).newDecoder()                        .decode(buffer).toString();                System.out.println("received form client: " + receivedString);                String sendString = "received data: " + receivedString;                buffer = ByteBuffer.wrap(sendString.getBytes(localCharset));                sc.write(buffer);                sc.close();            }        }    }}

0 0