【Java基于Socket文件传输示例】网络编程

Java基于Socket文件传输示例最近需要进行网络传输大文件，于是对基于socket的文件传输作了一个初步的了解。

在一位网友提供的程序基础上，俺进行了一些加工，采用了缓冲输入/输出流来包装输出流，再采用数据输入/输出输出流进行包装，加快传输的速度。

废话少说，先来看服务器端的程序。

1.服务器端package sterning;import java.io.BufferedInputStream;import java.io.DataInputStream;import java.io.DataOutputStream;import java.io.File;import java.io.FileInputStream;import .ServerSocket;import .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 BufferedIn putStream(s.getInputStream()));dis.readByte();DataInputStream fis = new DataInputStream(new BufferedIn putStream(new FileInputStream(filePath)));DataOutputStream ps = new DataOutputStream(s.getOutput Stream());//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 .*;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 BufferedInputS tream(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IPprivate 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 Buffer edOutputStream(new BufferedOutputStream(new FileOutputStream(saveP ath))));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();}}这就实现了从服务器端向客户端发送文件的过程,当然,反过来,也一样.稍有不同.代码中对跨平台的细节没有实现,有时间或兴趣的朋友可以提供一下.。