Java 网络编程之 TCP 实现简单的聊天系统

package lesson02;

import java.io.IOException;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;

/**
 * 客户端
 */
public class TcpClientDemo1 {

  public static void main(String[] args) {

    Socket socket = null;
    OutputStream os = null;

    try {
      //1、要知道服务器的地址 端口号
      InetAddress serverIP = InetAddress.getByName("127.0.0.1");
      int port = 9999;
      //2、创建一个 socket 连接
      socket = new Socket(serverIP, port);
      //3、发送消息 IO流
      os = socket.getOutputStream();
      os.write("你好，欢迎学习狂神学Java".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();
        }
      }
    }
  }

}

package lesson02;

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 TcpServerDemo1 {

  public static void main(String[] args) {

    ServerSocket serverSocket = null;
    Socket socket = null;
    InputStream is = null;
    ByteArrayOutputStream baos = null;

    try {
      //1、我得有一个地址
      serverSocket = new ServerSocket(9999);

      while (true){
        //2、等待客户端连接过来
        socket = serverSocket.accept();
        //3、读取客户端的消息
        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());
      }

      /*
      byte[] buffer = new byte[1024];
      int len;
      while ((len = is.read(buffer)) != -1){
        String msg = new String(buffer, 0, len);
        System.out.println(msg);
      }
      */

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

/**
 * 服务端
 */
public class TcpServerDemo1 {

  public static void main(String[] args) {

    ServerSocket serverSocket = null;
    Socket socket = null;
    InputStream is = null;
    ByteArrayOutputStream baos = null;

    try {
      //1、我得有一个地址
      serverSocket = new ServerSocket(9999);

      while (true){
        //2、等待客户端连接过来
        socket = serverSocket.accept();
        //3、读取客户端的消息
        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());
      }

      /*
      byte[] buffer = new byte[1024];
      int len;
      while ((len = is.read(buffer)) != -1){
        String msg = new String(buffer, 0, len);
        System.out.println(msg);
      }
      */

    } 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();
        }
      }
    }
  }

}