本文实例讲述了Java基于Socket的文件传输实现方法。分享给大家供大家参考，具体如下：

1. Java代码如下：

package sterning;import java.io.BufferedInputStream;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import java.net.ServerSocket;import java.net.Socket;public class ServerTest { int port = 8821; void start() { Socket s = null; try { ServerSocket ss = new ServerSocket(port); while (true) { // 选择进行传输的文件 String filePath = "D:\\lib.rar"; File fi = new File(filePath); System.out.println("文件长度:" + (int) fi.length()); // public Socket accept() throws // IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。 s = ss.accept(); System.out.println("建立socket链接"); DataInputStream dis = new DataInputStream(new BufferedInputStream(s.getInputStream())); dis.readByte(); DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath))); DataOutputStream ps = new DataOutputStream(s.getOutputStream()); //将文件名及长度传给客户端。这里要真正适用所有平台，例如中文名的处理，还需要加工，具体可以参见Think In Java 4th里有现成的代码。 ps.writeUTF(fi.getName()); ps.flush(); ps.writeLong((long) fi.length()); ps.flush(); int bufferSize = 8192; byte[] buf = new byte[bufferSize]; while (true) { int read = 0; if (fis != null) { read = fis.read(buf); } if (read == -1) { break; } ps.write(buf, 0, read); } ps.flush(); // 注意关闭socket链接哦，不然客户端会等待server的数据过来， // 直到socket超时，导致数据不完整。 fis.close(); s.close(); System.out.println("文件传输完成"); } } catch (Exception e) { e.printStackTrace(); } } public static void main(String arg[]) { new ServerTest().start(); }}

2.socket的Util辅助类

package sterning;import java.net.*;import java.io.*;public class ClientSocket { private String ip; private int port; private Socket socket = null; DataOutputStream out = null; DataInputStream getMessageStream = null; public ClientSocket(String ip, int port) { this.ip = ip; this.port = port; } /** *//** * 创建socket连接 * * @throws Exception * exception */ public void CreateConnection() throws Exception { try { socket = new Socket(ip, port); } catch (Exception e) { e.printStackTrace(); if (socket != null) socket.close(); throw e; } finally { } } public void sendMessage(String sendMessage) throws Exception { try { out = new DataOutputStream(socket.getOutputStream()); if (sendMessage.equals("Windows")) { out.writeByte(0x1); out.flush(); return; } if (sendMessage.equals("Unix")) { out.writeByte(0x2); out.flush(); return; } if (sendMessage.equals("Linux")) { out.writeByte(0x3); out.flush(); } else { out.writeUTF(sendMessage); out.flush(); } } catch (Exception e) { e.printStackTrace(); if (out != null) out.close(); throw e; } finally { } } public DataInputStream getMessageStream() throws Exception { try { getMessageStream = new DataInputStream(new BufferedInputStream(socket.getInputStream())); return getMessageStream; } catch (Exception e) { e.printStackTrace(); if (getMessageStream != null) getMessageStream.close(); throw e; } finally { } } public void shutDownConnection() { try { if (out != null) out.close(); if (getMessageStream != null) getMessageStream.close(); if (socket != null) socket.close(); } catch (Exception e) { } }}

3.客户端

package sterning;import java.io.BufferedOutputStream;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.FileOutputStream;public class ClientTest { private ClientSocket cs = null; private String ip = "localhost";// 设置成服务器IP private int port = 8821; private String sendMessage = "Windwos"; public ClientTest() { try { if (createConnection()) { sendMessage(); getMessage(); } } catch (Exception ex) { ex.printStackTrace(); } } private boolean createConnection() { cs = new ClientSocket(ip, port); try { cs.CreateConnection(); System.out.print("连接服务器成功!" + "\n"); return true; } catch (Exception e) { System.out.print("连接服务器失败!" + "\n"); return false; } } private void sendMessage() { if (cs == null) return; try { cs.sendMessage(sendMessage); } catch (Exception e) { System.out.print("发送消息失败!" + "\n"); } } private void getMessage() { if (cs == null) return; DataInputStream inputStream = null; try { inputStream = cs.getMessageStream(); } catch (Exception e) { System.out.print("接收消息缓存错误\n"); return; } try { //本地保存路径，文件名会自动从服务器端继承而来。 String savePath = "E:\\"; int bufferSize = 8192; byte[] buf = new byte[bufferSize]; int passedlen = 0; long len=0; savePath += inputStream.readUTF(); DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(new BufferedOutputStream(new FileOutputStream(savePath)))); len = inputStream.readLong(); System.out.println("文件的长度为:" + len + "\n"); System.out.println("开始接收文件!" + "\n"); while (true) { int read = 0; if (inputStream != null) { read = inputStream.read(buf); } passedlen += read; if (read == -1) { break; } //下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比 System.out.println("文件接收了" + (passedlen * 100/ len) + "%\n"); fileOut.write(buf, 0, read); } System.out.println("接收完成，文件存为" + savePath + "\n"); fileOut.close(); } catch (Exception e) { System.out.println("接收消息错误" + "\n"); return; } } public static void main(String arg[]) { new ClientTest(); }}

希望本文所述对大家Java程序设计有所帮助。