Socket发送和接收

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;

public class SocketIOPropertites {
    //server socket listen property:
    private static final int RECEIVE_BUFFER = 10;
    private static final int SO_TIMEOUT = 0;
    private static final boolean REUSE_ADDR = false;
    private static final int BACK_LOG = 2;
    //client socket listen property on server endpoint:
    private static final boolean CLI_KEEPALIVE = false;
    private static final boolean CLI_OOB = false;
    private static final int CLI_REC_BUF = 20;
    private static final boolean CLI_REUSE_ADDR = false;
    private static final int CLI_SEND_BUF = 20;
    private static final boolean CLI_LINGER = true;
    private static final int CLI_LINGER_N = 0;
    private static final int CLI_TIMEOUT = 0;
    private static final boolean CLI_NO_DELAY = false;
/*
    StandardSocketOptions.TCP_NODELAY
    StandardSocketOptions.SO_KEEPALIVE
    StandardSocketOptions.SO_LINGER
    StandardSocketOptions.SO_RCVBUF
    StandardSocketOptions.SO_SNDBUF
    StandardSocketOptions.SO_REUSEADDR
 */
    public static void main(String[] args) {
        ServerSocket server = null;
        try {
            server = new ServerSocket();
            server.bind(new InetSocketAddress(9090), BACK_LOG);
            server.setReceiveBufferSize(RECEIVE_BUFFER);
            server.setReuseAddress(REUSE_ADDR);
            server.setSoTimeout(SO_TIMEOUT);
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println("server up use 9090!");
        try {
            while (true) {
                Socket client = server.accept();  //阻塞的，没有 -1  一直卡着不动  accept(4,
                System.out.println("client port: " + client.getPort());
                client.setKeepAlive(CLI_KEEPALIVE);
                client.setOOBInline(CLI_OOB);
                client.setReceiveBufferSize(CLI_REC_BUF);
                client.setReuseAddress(CLI_REUSE_ADDR);
                client.setSendBufferSize(CLI_SEND_BUF);
                client.setSoLinger(CLI_LINGER, CLI_LINGER_N);
                client.setSoTimeout(CLI_TIMEOUT);
                client.setTcpNoDelay(CLI_NO_DELAY);
                //client.read   //阻塞   没有  -1 0
                new Thread(
                        () -> {
                            try {
                                InputStream in = client.getInputStream();
                                BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                                char[] data = new char[1024];
                                while (true) {
                                    int num = reader.read(data);
                                    if (num > 0) {
                                        System.out.println("client read some data is :" + num + " val :" + new String(data, 0, num));
                                    } else if (num == 0) {
                                        System.out.println("client readed nothing!");
                                        continue;
                                    } else {
                                        System.out.println("client readed -1...");
                                        System.in.read();
                                        client.close();
                                        break;
                                    }
                                }
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                ).start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                server.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

public class SocketIO {
    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(9090,20);
        System.out.println("step1: new ServerSocket(9090) ");
        while (true) {
            Socket client = server.accept();  //阻塞1
            System.out.println("step2:client\t" + client.getPort());
            new Thread(() -> {
                InputStream in = null;
                try {
                    in = client.getInputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(in));
                    while(true){
                        String dataline = reader.readLine(); //阻塞2
                        if(null != dataline){
                            System.out.println(dataline);
                        }else{
                            client.close();
                            break;
                        }
                    }
                    System.out.println("客户端断开");
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }).start();
        }
    }
}

[root@dev-nfs01 ~]# nc 172.25.207.** 9090
hajkdfhjaksdfhkjasdhfkjahsdjkfjkasdf
afasdfasdfadsf00000

import java.io.*;
import java.net.Socket;

public class SocketClient {
    public static void main(String[] args) {
        try {
            Socket client = new Socket("127.0.0.1", 9090);
            client.setSendBufferSize(20); // 设置发送端缓冲区的大小
            // 本地局域网测试暂未发现优缺
            // 可以参考 https://www.jianshu.com/p/ccafdeda0b95
            client.setTcpNoDelay(false);
            OutputStream out = client.getOutputStream();
            InputStream in = System.in;
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            while (true){
                String line = reader.readLine();
                if (null != line){
                    byte[] bb = line.getBytes();
                    for (byte b : bb) {
                        out.write(b);
                    }
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}