【求助帖】初学java 写了个程序用于一台机器向另一台机器传输文件，客户端一直接收不到服务器的包，求帮忙找错，在线等

2016-06-19 07:10:19 204 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

java网络编程-利用datagramsocket和datagrampacket实现一台机器向另一台机器传文件编写程序，利用数据包（Datagram）将一个文件从一台机器传到另一台机器上。【服务器端】 1）服务器启动，等待客户想服务器发送数据包 2）服务器收到客户端发来的数据包，确认用户端的存在并于用户端建立连接 3）读取文件路径和文件名，打包发送 4）将文件读入到缓冲流，再按字节数组读，将字节数组打包发送。 5）数据读到流末端时，发送数据包，程序结束。【客户端】阅读详情

已经调试一下午了...
服务器端：

public class thi4server {

	public static void main(String[] args) throws IOException {



		DatagramSocket filereceive = new DatagramSocket(1234);



		byte[] data = new byte[1024];

		DatagramPacket packet = new DatagramPacket(data, data.length);

		System.out.println("****服务器端已经启动，等待客户端发送数据******");

		filereceive.receive(packet);// 此方法在接收到数据报之前会一直阻塞

		System.out.println("客户端存在，开始向客户端传输文件。");



		//System.out.println("我是服务器，客户端说："+(new String(data, 0, data.length)) + packet.getAddress()+"   "+packet.getPort()+"   "+packet.getSocketAddress());

		/* * 向客户端响应数据 */



		String filename = "e:\\ForTransformTest.txt";

		File file = new File(filename);

		BufferedInputStream br = new BufferedInputStream(new FileInputStream(file));



		// 发送文件名和路径

		DatagramSocket filesend = new DatagramSocket();

		//System.out.println(new String(filename.getBytes(), 0, filename.getBytes().length));

		DatagramPacket packet2 = new DatagramPacket(filename.getBytes(), filename.getBytes().length, packet.getAddress(),1234);

		filesend.send(packet2);

		

		// 2.从缓冲流中按字节读取文件，打包发送

		byte[] data2 = new byte[1024];

		while (br.read(data2) != -1) {

			//System.out.println(new String(data2,0,data2.length));

			DatagramPacket packet3 = new DatagramPacket(data2, data2.length, packet.getAddress(),1234);

			filesend.send(packet3);

		}

		System.out.println("Done!");

		filesend.close();

	}

}

客户端：

public class thi4client {

	public static void main(String[] args) throws IOException {

		try {

			InetAddress address = InetAddress.getByName("192.168.1.101");

			int port = 1234;

			byte[] data = "hello".getBytes();



			DatagramPacket packet = new DatagramPacket(data, data.length, address, port);

			DatagramSocket filesend = new DatagramSocket();



			System.out.println("before sending");

			filesend.send(packet);

			System.out.println("after sending" + " " + packet.getSocketAddress());



			DatagramSocket filerecieve = new DatagramSocket(port);

			byte[] data2 = new byte[1024];

			DatagramPacket packetfilename = new DatagramPacket(data2, data2.length);



			System.out.println("before receiving");

			filerecieve.receive(packetfilename);//卡在这儿，一直没收到

			System.out.println("after receiving");



			String filename = new String(data2, 0, packetfilename.getLength());

			OutputStreamWriter osw = new OutputStreamWriter(new FileOutputStream(filename));



			byte[] data3 = new byte[4096];

			DatagramPacket packetfilecontain = new DatagramPacket(data3, data3.length);

			{

				filerecieve.receive(packetfilecontain);

				String filecontain = new String(data3, 0, packetfilecontain.getLength());

				osw.write(filecontain);

			}

			osw.close();

		} catch (Exception e) {

			// TODO: handle exception

			e.printStackTrace();

		}



	}

}