TCP实现聊天

package lesson02;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

//服务端
public class TcpServerDemo01 {
    public static void main(String[] args) {
      //我要有一个地址
        ServerSocket serverSocket =null;
        Socket socket =null;
        InputStream is=null;
        ByteArrayOutputStream baos =null;

        try {
            serverSocket = new ServerSocket(9999);
            while(true) {
                //等待客户端连接过来
                socket = serverSocket.accept();
                //读取客户端消息
                is = socket.getInputStream();
                //管道流
                baos = new ByteArrayOutputStream();
                byte[] buffer = new byte[1024];
                int len;
                while ((len = is.read(buffer)) != -1) {
                    baos.write(buffer, 0, len);
                }
                System.out.println(baos.toString());
            }

        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            //关闭资源
            if(baos!=null) {
                try {
                    baos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(is!=null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(socket!=null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(serverSocket!=null) {
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

---

package lesson02;

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.nio.charset.StandardCharsets;

public class TcpClinentDemo01 {
    public static void main(String[] args) {
        Socket socket=null;
        OutputStream os=null;
        try {
            InetAddress serverIP = InetAddress.getByName("127.0.0.1");
            int port=9999;
            //3创建一个socket连接
            socket = new Socket(serverIP,port);
            os = socket.getOutputStream();
            os.write("你好".getBytes());

        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

            if(socket!=null) {
                try {
                    socket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

        }
    }