java复习第十九天 线程池 聊天室 文件上传和下载 网络传输

1.线程池的创建

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

//一个程序中只能有一个线程池
public class ThreadPoolDemo {
	public static void main(String[] args) {
		//public static ExecutorService newCachedThreadPool()创建一个可根据需要创建新线程的线程池，但是在以前构造的线程可用时将重用它们。线程存活时间是60s
		ExecutorService threadPool = Executors.newCachedThreadPool();
		//void execute(Runnable command)在未来某个时间执行给定的命令
		Runnable command = new Runnable() {
			@Override
			public void run() {
				System.out.println(Thread.currentThread().getName()+"执行了");
			}
		};
		//threadPool.execute(command);
		
		//public static ExecutorService newSingleThreadExecutor()创建只有一个线程的线程池。如果线程不显示的关闭，线程将一直存活着
		threadPool = Executors.newSingleThreadExecutor();
		//threadPool.execute(command);
		
		//public static ExecutorService newFixedThreadPool(int nThreads)创建一个可重用固定线程数的线程池。如果线程不显示的关闭，线程将一直存活着
		threadPool = Executors.newFixedThreadPool(1);
		//threadPool.execute(command);
		//threadPool.execute(command);
		
		//关闭线程池：void shutdown()启动一次顺序关闭，执行以前提交的任务，但不接受新任务
		//threadPool.shutdown();//等整个程序退出的时候需要把线程池关闭
		
		//new Thread(command).start();//我们自己创建线程
		ThreadPoolUtils.execute(command);//pool-4-thread-1执行了
		ThreadPoolUtils.shutdown();
		ThreadPoolUtils.execute(command);//pool-5-thread-1执行了
	}
}

2.工具包  子类对象交由线程执行

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadPoolUtils {
	private static ExecutorService threadPool = Executors.newCachedThreadPool();

	/**
	 * 将Runnable子类对象交由线程池执行
	 * 
	 * @param command
	 */
	public static void execute(Runnable command) {
		// 判断线程池是否被关闭
		if (threadPool.isShutdown()) {
			// 如果线程池被关闭了，那么就新建一个线程池
			threadPool = Executors.newCachedThreadPool();
			execute(command);// 再次将任务交给线程池执行
		} else {
			threadPool.execute(command);
		}
	}

	/**
	 * 关闭线程池
	 */
	public static void shutdown() {
		threadPool.shutdown();
	}
}

3.定时器的用法

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;

/*
 * Timer：一种工具，线程用其安排以后在后台线程中执行的任务。可安排任务执行一次，或者定期重复执行。
 * TimerTask：由 Timer 安排为一次执行或重复执行的任务。 
 */
public class TimerDemo {
	public static void main(String[] args) {
		test2();
	}

	private static void test2() {
		//public Timer()创建一个新计时器。相关的线程不 作为守护程序运行
		Timer timer = new Timer();
		//protected TimerTask()创建一个新的计时器任务
		TimerTask task = new TimerTask() {
			@Override
			public void run() {
				SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
				String time = sdf.format(new Date());
				System.out.println(time);
			}
		};
		/*
		 * public void schedule(TimerTask task,
                     long delay,
                     long period)安排指定的任务从指定的延迟后开始进行重复的固定延迟执行
		           参数：
				task - 所要安排的任务。
				delay - 执行任务前的延迟时间，单位是毫秒。
				period - 执行各后续任务之间的时间间隔，单位是毫秒。 
		 */
		timer.schedule(task, 0, 1000);
	}

	private static void test() {
		//public Timer()创建一个新计时器。相关的线程不 作为守护程序运行
		Timer timer = new Timer();
		
		//protected TimerTask()创建一个新的计时器任务
		TimerTask task = new TimerTask() {
			@Override
			public void run() {
				System.out.println("定时器执行的任务");
			}
		};
		/*
		 * public void schedule(TimerTask task,long delay)安排在指定延迟后执行指定的任务。 
                         参数：
		 * 	task - 所要安排的任务。 
		 * 	delay - 执行任务前的延迟时间，单位是毫秒。
		 */
		timer.schedule(task, 1000);
		
		//public boolean cancel()取消此计时器任务
		//task.cancel();//终止的是任务
		
		
		//public void cancel()终止此计时器，丢弃所有当前已安排的任务
		timer.cancel();//终止此计时器
		
		task = new TimerTask() {
			@Override
			public void run() {
				System.out.println("定时器执行的任务");
			}
		};
		timer.schedule(task, 1000);
		
		//一个定时器任务能不能被执行多次？不行的
		//timer.schedule(task, 3000);//Task already scheduled or cancelled
	}
	
	//安排在指定延迟后执行指定的任务。 
	public void schedule(Runnable task,long delay){
		//创建一个线程
		new Thread(new Runnable() {
			@Override
			public void run() {
				//延迟指定delay的时间
				try {
					Thread.sleep(delay);
					task.run();//run方法就执行在子线程中
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
		}).start();
	}
}

4.网络传输之UDP

server

import java.net.DatagramPacket;
import java.net.DatagramSocket;

//DatagramSocket：此类表示用来发送和接收数据包的套接字
public class Server {
	public static void main(String[] args) throws Exception {
		//1.创建Socket对象并监听指定的端口
		DatagramSocket s = new DatagramSocket(8888);
		//2.创建一个数据包容器用于存储数据，udp一次传输的数据包最大是64k
		//public DatagramPacket(byte[] buf,int length)	buf - 保存传入数据报的缓冲区。len - 要读取的字节数。
		DatagramPacket p = new DatagramPacket(new byte[1024*64], 1024*64);
		//3.接收数据
		//public void receive(DatagramPacket p)从此套接字接收数据包
		s.receive(p);
		//4.拆开数据包，取出内容
		//public byte[] getData()返回数据缓冲区
		byte[] data = p.getData();
		//public int getLength()返回将要发送或接收到的数据的长度
		int len = p.getLength();//实际接收的字节个数
		//将读取的内容转换成字符串
		String content = new String(data,0,len);
		String ip = p.getAddress().getHostAddress();
		System.out.println("ip="+ip+0+",内容="+content);
		//5.释放资源
		s.close();
	}
}

client

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

/*
 * DatagramSocket：此类表示用来发送和接收数据包的套接字
 * DatagramPacket：此类表示数据包
 */
public class Client {
	public static void main(String[] args) throws Exception {
		//1.创建Socket对象
		//public DatagramSocket()构造数据报套接字并将其绑定到本地主机上任何可用的端口
		DatagramSocket s = new DatagramSocket();
		//2.构建要发送的数据包，在数据包中指定要发送的内容，发送目标的ip地址，端口号
		//public DatagramPacket(byte[] buf,int length,InetAddress address,int port)构造数据报包，用来将长度为 length 的包发送到指定主机上的指定端口号
		byte[] buf = "udp，我来了~".getBytes(); //包数据
		int length = buf.length;//包长度
		InetAddress address = InetAddress.getByName("192.168.3.54");//目的地址。
		int port = 8888;//port
		DatagramPacket p = new DatagramPacket(buf, length, address, port);
		//3.发送数据包到服务端
		//public void send(DatagramPacket p)从此套接字发送数据包
		s.send(p);
		//4.关闭资源
		//public void close()关闭此数据报套接字。 
		s.close();
	}
}

5.网络传输之TCP

server

import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
	public static void main(String[] args) throws Exception {
		//1.创建ServerSocket对象并监听指定的端口号
		ServerSocket ss = new ServerSocket(8888);
		//2.接受客户端的连接请求
		//public Socket accept()侦听并接受到此套接字的连接。此方法在连接传入之前一直阻塞。
		Socket s = ss.accept();
		//3.获取字节读取流
		InputStream in = s.getInputStream();
		//4.读取数据
		byte[] b = new byte[1024];
		int len = in.read(b);//len是实际读取的字节个数
		//把接收到的数据转换成字符串
		String content = new String(b,0,len);
		String ip = s.getInetAddress().getHostAddress();
		System.out.println("ip="+ip+",内容="+content);
		//5.关闭资源
		s.close();//连接对象关闭
		ss.close();//服务器关闭
	}
}

client

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

public class Client {
	public static void main(String[] args) throws Exception {
		// 1.创建Socket对象并指定ip地址和端口号
		Socket s = new Socket("192.168.3.54", 8888);
		// 2.获取字节输出流
		OutputStream out = s.getOutputStream();
		// 3.写出数据到服务端
		out.write("tcp，我来了~".getBytes());
		// 4.关闭资源
		s.close();
	}
}

6.

服务器给客户端反馈内容

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

//服务器给客户端反馈内容
public class Server {
	public static void main(String[] args) throws Exception {
		// 1.创建ServerSocket对象并监听指定的端口号
		ServerSocket ss = new ServerSocket(8888);
		// 2.接收客户的请求
		Socket s = ss.accept();
		// 3.将字节读取流包装成字符缓冲读取流
		InputStream in = s.getInputStream();
		InputStreamReader isr = new InputStreamReader(in);
		BufferedReader br = new BufferedReader(isr);
		// 4.读取内容
		String result = br.readLine();
		System.out.println(result);
		// 5.反馈结果给客户端，将字节输出流包装成字符缓冲输出流
		OutputStream out = s.getOutputStream();
		OutputStreamWriter osw = new OutputStreamWriter(out);
		BufferedWriter bw = new BufferedWriter(osw);
		// 6.将反馈结果返回给客户端
		if (result.contains("钱")) {
			bw.write("我也很穷啊，没钱");
			bw.newLine();
			bw.flush();
		} else {
			bw.write("我在啊，有啥事");
			bw.newLine();
			bw.flush();
		}
		// 7.关闭资源
		s.close();
		ss.close();
	}
}

client

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.Socket;

public class Client {
	public static void main(String[] args) throws Exception {
		// 1.创建Socket对象并指定ip地址和端口号
		Socket s = new Socket("192.168.3.54", 8888);
		// 2.将获取的字节输出流包装成字符缓冲输出流
		OutputStream out = s.getOutputStream();
		OutputStreamWriter osw = new OutputStreamWriter(out);
		BufferedWriter bw = new BufferedWriter(osw);
		// 3.写出数据
		bw.write("在吗？借点钱花花");
		bw.newLine();
		bw.flush();
		// 4.获取服务端的返回消息，将字节读取流包装成字符缓冲读取流
		InputStream in = s.getInputStream();
		InputStreamReader isr = new InputStreamReader(in);
		BufferedReader br = new BufferedReader(isr);
		String result = br.readLine();
		System.out.println(result);
		// 5.关闭资源
		s.close();
	}
}

7.

客户端键盘录入内容，服务器输出到控制台

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

//客户端键盘录入内容，服务器输出到控制台
public class Server {
	public static void main(String[] args) throws Exception {
		// 1.创建ServerSocket对象并监听指定的端口号
		ServerSocket ss = new ServerSocket(8888);
		// 2.接受客户端的请求
		while (true) {// 可以一直接受客户端的请求
			Socket s = ss.accept();//阻塞式
			// 3.将字节读取流包装成字符缓冲读取流
			BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
			String line;// 用于保存每次读取的内容
			while ((line = br.readLine()) != null) {
				System.out.println(line);
			}
			// 4.关闭请求资源
			s.close();
		}
	}
}

client

import java.io.BufferedWriter;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.util.Scanner;

//客户端键盘录入内容，服务器输出到控制台
public class Client {
	public static void main(String[] args) throws Exception {
		// 1.创建Socket对象并指定ip地址和端口号
		Socket s = new Socket("192.168.3.54", 8888);
		// 2.将字节输出流包装成字符缓冲输出流
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
		// 3.键盘录入数据，输出到服务端
		Scanner sc = new Scanner(System.in);
		while (true) {
			String content = sc.nextLine();
			if (content.equals("886")) {
				break;
			}
			// 4.写出内容到服务端
			bw.write(content);
			bw.newLine();
			bw.flush();
		}
		// 5.关闭资源
		s.close();
	}
}

8.客户端上传文件，服务器端保存起来

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.net.Socket;

//客户端上传文件，服务端保存起来
public class UploadClient {
	public static void main(String[] args) throws Exception {
		// 1.创建Socket对象并指定ip地址和端口号
		Socket s = new Socket("192.168.3.54", 8888);
		// 2.因为上传的文件类型不确定，所以将字节输出流包装成字节缓冲输出流
		BufferedOutputStream bos = new BufferedOutputStream(s.getOutputStream());
		// 3.将要上传的文件封装到字节缓冲读取流中
		BufferedInputStream bis = new BufferedInputStream(new FileInputStream("E:/悟空.jpg"));
		// 4.循环的读写
		byte[] buf = new byte[1024];
		int len;
		while ((len = bis.read(buf)) != -1) {
			bos.write(buf, 0, len);
		}
		// 5.将数据刷新到服务端并且告诉服务端数据发送完毕
		bos.flush();
		s.shutdownOutput();//禁用此套接字的输出流
		
		// 6.接收服务端的返回结果，将字节读取流包装成字符缓冲读取流
		BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
		System.out.println(br.readLine());
		// 7.关闭资源
		bis.close();// 自己创建的资源
		s.close();
	}
}

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.UUID;

public class UploadServer {
	public static void main(String[] args) throws Exception {
		// 1.创建ServerSocket对象并监听指定的端口号
		ServerSocket ss = new ServerSocket(8888);
		// 2.接收客户端请求连接
		while (true) {// 一直接收客户端的请求
			Socket s = ss.accept();
			// 3.将字节读取流包装成字节缓冲读取流
			BufferedInputStream bis = new BufferedInputStream(s.getInputStream());
			// 4.将要保存的字节数据写出到一个文件中，创建字节缓冲输出流
			BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("D:/" + getUUID() + ".jpg"));
			// 5.循环读写
			byte[] buf = new byte[1024];
			int len;
			while ((len = bis.read(buf)) != -1) {
				bos.write(buf, 0, len);
			}
			// 6.将数据刷新到硬盘
			bos.flush();
			// 7.将上传结果返回给客户端，将字节输出流封装成字符缓冲输出流
			System.out.println("上传文件成功");
			BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
			bw.write("上传文件成功");
			bw.newLine();
			bw.flush();
			// 8.关闭资源
			bos.close();//自己创建的资源关闭
			s.close();//请求对象关闭
		}
	}

	public static String getUUID() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}
}

9.

server

import java.net.ServerSocket;
import java.net.Socket;

public class UploadServer {
	public static void main(String[] args) throws Exception {
		// 1.创建ServerSocket对象并监听指定的端口号
		ServerSocket ss = new ServerSocket(8888);
		// 2.接收客户端请求连接
		while (true) {// 一直接收客户端的请求
			Socket s = ss.accept();
			//接收到请求任务之后，将任务交给子线程来处理，因为可能有多个请求，所以需要启动多个子线程，所以使用线程池比较合理
			ThreadPoolUtils.execute(new ServerRunnable(s));
		}
	}
}

client

//客户端上传文件，服务端保存起来
public class UploadClient {
	public static void main(String[] args) throws Exception {
		ThreadPoolUtils.execute(new ClientRunnable("192.168.3.54", 8888, "E:/修仙.txt"));
		ThreadPoolUtils.execute(new ClientRunnable("192.168.3.54", 8888, "E:/修仙.txt"));
		ThreadPoolUtils.execute(new ClientRunnable("192.168.3.54", 8888, "E:/修仙.txt"));
		ThreadPoolUtils.execute(new ClientRunnable("192.168.3.54", 8888, "E:/修仙.txt"));
	}
}

ServerRunnable

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.util.UUID;

public class ServerRunnable implements Runnable {
	private Socket s;

	public ServerRunnable(Socket s) {
		super();
		this.s = s;
	}

	@Override
	public void run() {
		try {
			// 3.将字节读取流包装成字节缓冲读取流
			BufferedInputStream bis = new BufferedInputStream(s.getInputStream());
			// 4.将要保存的字节数据写出到一个文件中，创建字节缓冲输出流
			BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("D:/" + getUUID() + ".txt"));
			// 5.循环读写
			byte[] buf = new byte[1024];
			int len;
			while ((len = bis.read(buf)) != -1) {
				bos.write(buf, 0, len);
			}
			// 6.将数据刷新到硬盘
			bos.flush();
			// 7.将上传结果返回给客户端，将字节输出流封装成字符缓冲输出流
			System.out.println("上传文件成功");
			BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
			bw.write("上传文件成功");
			bw.newLine();
			bw.flush();
			// 8.关闭资源
			bos.close();// 自己创建的资源关闭

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (null != s) {
				try {
					s.close();
				} catch (IOException e) {
					e.printStackTrace();
				} // 请求对象关闭
			}
		}

	}

	public static String getUUID() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}

}

ThreadPoolUtils

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadPoolUtils {
	private static ExecutorService threadPool = Executors.newCachedThreadPool();

	public static void execute(Runnable command) {
		threadPool.execute(command);
	}
}

ClientRunnable

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.net.Socket;

public class ClientRunnable implements Runnable {
	private String ip;
	private int port;
	private String uploadPath;

	public ClientRunnable(String ip, int port, String uploadPath) {
		super();
		this.ip = ip;
		this.port = port;
		this.uploadPath = uploadPath;
	}

	@Override
	public void run() {
		try (// 1.创建Socket对象并指定ip地址和端口号
				Socket s = new Socket(ip, port);
				// 3.将要上传的文件封装到字节缓冲读取流中
				BufferedInputStream bis = new BufferedInputStream(new FileInputStream(uploadPath));) {
			// 2.因为上传的文件类型不确定，所以将字节输出流包装成字节缓冲输出流
			BufferedOutputStream bos = new BufferedOutputStream(s.getOutputStream());

			// 4.循环的读写
			byte[] buf = new byte[1024];
			int len;
			while ((len = bis.read(buf)) != -1) {
				bos.write(buf, 0, len);
			}
			// 5.将数据刷新到服务端并且告诉服务端数据发送完毕
			bos.flush();
			s.shutdownOutput();// 禁用此套接字的输出流
			// 6.接收服务端的返回结果，将字节读取流包装成字符缓冲读取流
			BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
			System.out.println(br.readLine());
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}

inetAddressDemo

import java.net.InetAddress;

public class InetAddressDemo {
	public static void main(String[] args) throws Exception {
		//public static InetAddress getByName(String host)在给定主机名的情况下确定主机的 IP 地址。
		InetAddress inetAddress = InetAddress.getByName("www.taobao.cn");
		//public String getHostAddress()返回 IP 地址字符串（以文本表现形式）。 
		String ip = inetAddress.getHostAddress();
		System.out.println(ip);//192.168.3.106
		//public String getHostName()获取此 IP 地址的主机名。 
		String hostName = inetAddress.getHostName();
		System.out.println(hostName);//LENOVO-PC
		
		//public static InetAddress getLocalHost()返回本地主机
		InetAddress localHost = InetAddress.getLocalHost();
		System.out.println(localHost.getHostAddress());//192.168.200.1
		System.out.println(localHost.getHostName());//DESKTOP-NT06AQ5
	}
}

10.聊天室

client

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;

public class Client {
	public static void main(String[] args) throws Exception {
		// 1.创建Socket对象
		DatagramSocket s = new DatagramSocket();
		// 2.构建数据包，内容应该是键盘录入
		Scanner sc = new Scanner(System.in);
		byte[] bytes;
		DatagramPacket p;
		while (true) {
			String content = sc.nextLine();
			// 如果用户输入886就表示结束输入
			if (content.equals("886")) {
				break;
			}
			bytes = content.getBytes();
			p = new DatagramPacket(bytes, bytes.length, InetAddress.getByName("192.168.3.255"), 8888);
			// 3.发送数据包
			s.send(p);
		}
		// 3.关闭资源
		s.close();
	}
}

ClientRunnable

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Scanner;

public class ClientRunnable implements Runnable {
	private String ip;
	private int port;

	public ClientRunnable(String ip, int port) {
		super();
		this.ip = ip;
		this.port = port;
	}

	@Override
	public void run() {

		try (// 1.创建Socket对象
				DatagramSocket s = new DatagramSocket();) {
			// 2.构建数据包，内容应该是键盘录入
			Scanner sc = new Scanner(System.in);
			byte[] bytes;
			DatagramPacket p;
			while (true) {
				String content = sc.nextLine();
				// 如果用户输入886就表示结束输入
				if (content.equals("886")) {
					break;
				}
				bytes = content.getBytes();
				p = new DatagramPacket(bytes, bytes.length, InetAddress.getByName(ip), port);
				// 3.发送数据包
				s.send(p);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}

chatroom

public class ChatRoom {
	public static void main(String[] args) {
		ServerRunnable serverRunnable = new ServerRunnable(8888);
		ClientRunnable clientRunnable = new ClientRunnable("192.168.3.255", 8888);
		
		ThreadPoolUtils.execute(serverRunnable);
		ThreadPoolUtils.execute(clientRunnable);
	}
}

server

import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class Server {
	public static void main(String[] args) throws Exception {
		// 1.创建Socket对象并监听指定的端口号
		DatagramSocket s = new DatagramSocket(8888);
		// 2.创建存放数据的数据包
		DatagramPacket p = new DatagramPacket(new byte[1024 * 64], 1024 * 64);
		// 3.循环的接收数据
		byte[] data;
		int len;
		String content;
		String ip;
		while (true) {
			s.receive(p);
			// 4.从包中取出内容
			data = p.getData();// 获取缓冲区
			len = p.getLength();// 获取实际的字节个数
			// 把接收的字节变成字符串
			content = new String(data, 0, len);
			ip = p.getAddress().getHostAddress();
			System.out.println("ip=" + ip + ",内容=" + content);
		}
	}
}

ServerRunnable

import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class ServerRunnable implements Runnable {
	private int port;

	public ServerRunnable(int port) {
		super();
		this.port = port;
	}


	@Override
	public void run() {
		try (// 1.创建Socket对象并监听指定的端口号
			DatagramSocket s = new DatagramSocket(port);) {
			// 2.创建存放数据的数据包
			DatagramPacket p = new DatagramPacket(new byte[1024 * 64], 1024 * 64);
			// 3.循环的接收数据
			byte[] data;
			int len;
			String content;
			String ip;
			while (true) {
				s.receive(p);
				// 4.从包中取出内容
				data = p.getData();// 获取缓冲区
				len = p.getLength();// 获取实际的字节个数
				// 把接收的字节变成字符串
				content = new String(data, 0, len);
				ip = p.getAddress().getHostAddress();
				System.out.println("ip=" + ip + ",内容=" + content);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

}

ThreadPoolUtils

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ThreadPoolUtils {
	private static ExecutorService threadPool = Executors.newCachedThreadPool();

	public static void execute(Runnable command) {
		threadPool.execute(command);
	}
}

   CS和BS结构介绍

TCP传输图解

广播地址图解

计算机网路图解

网络模型介绍

网络通信三要素

线程池图解