Java中 UDP 利用多线程,实现网络聊天室

利用多线程，实现网络聊天室

1：发送端的线程

• 2：接收端的线程

• 3：测试类

• 从上面两个来看，UDP编程时最好不要超过1472（针对以太网），如果要求不 高， 就算超过了1472了，

• 可以超过65507，即包总大小不要超过64k

    import java.io.IOException;
    import java.net.DatagramSocket;    
    public class Test {
    	public static void main(String[] args) throws IOException {
    		//1:创建发送端的实例
    		SendRunn sr = new SendRunn(new DatagramSocket());
    		//2:创建发送端的线程
    		Thread t1 = new Thread(sr);       		
    		//3:创建接收端的实例
    		ReceiveRunn rr = new ReceiveRunn(new DatagramSocket(10086));
    		//4:创建接受端的线程
    		Thread t2 = new Thread(rr);  		
    		//5:启动线程
    		t1.start();
        		t2.start();      		
        	}
        
        }
  

---

  import java.io.BufferedReader;
    import java.io.FileReader;
    import java.io.IOException;
    import java.net.DatagramPacket;
    import java.net.DatagramSocket;
    import java.net.InetAddress;
    import java.util.Scanner;
    
    /*
     * 发送端线程
     */
    public class SendRunn implements Runnable {
    	//声明发送端的套接字
    	private DatagramSocket ds;
    	public SendRunn(DatagramSocket ds) {
    		this.ds = ds;
    	}
    
    	@Override
    	public void run() {
    		
    		
    			 try {
    				 BufferedReader br = new BufferedReader(
    				                          new FileReader("斗破苍穹.txt"));
    				 char[] ch = new char[1024*1024];
    				 int read = br.read(ch);
    				 String info = new String(ch, 0,read);
    				
    				 //1数据
    				 byte[] by = info.getBytes();
    				 //1:创建数据包
    				DatagramPacket dp = new DatagramPacket(by, by.length, 
    				           InetAddress.getByName("192.168.3.255"), 10086);
    				//2:发送数据宝
    				ds.send(dp);
    				
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
        		
        		//关闭套集字
        		ds.close();
    
       }
    
     }

---

   import java.io.IOException;
    import java.net.DatagramPacket;
    import java.net.DatagramSocket;
    import java.net.InetAddress;
    import java.util.Date;
    
    public class ReceiveRunn implements Runnable {
	
	private DatagramSocket ds;
	public ReceiveRunn(DatagramSocket ds) {
		super();
		this.ds = ds;
	}



	@Override
	public void run() {
		
		while(true){
			//1:创建空的数据包
			byte[] by = new byte[1024*1024];
			DatagramPacket dp = new DatagramPacket(by, by.length);
			try {
				//2:接受数据，并且把数据封装到数据包中
				ds.receive(dp);
				//3:拆封数据
				byte[] data = dp.getData();
				int length = dp.getLength();
				InetAddress address = dp.getAddress();
				String hostName = address.getHostName();
				System.out.println(length);
				System.out.println(hostName+" "+new Date().toLocaleString());
				System.out.println(new String(by, 0, length));
			} catch (IOException e) {
				e.printStackTrace();
			}
			
		}
		
 

   }

  }