最近在一个课程设计，聊天系统，里面有个功能就是传输文件，我开先用的是udp数据报传输文件，但是发现当传输的文件太大的时候丢包，所以后改用java的socket 的tcp连接传输文件，在局域网中传输文件速度还是可以。
下面是部分代码，可能无法单独运行，因为里面涉及到图形界面，牵扯到其他的类，不过稍加改动就可以了，我把源代码上传到csdn上了，下载地址是：http://download.csdn.net/source/1957266，供大家下载学习使用，由于开发时间短，所以开发时客户端和服务器端共用了一些类，其实这应该分开的，呵呵！
本系统可以多客户端和服务器端进行通信，传输文件。界面不太好看，恶哈哈！
下面还是把传输文件的主要两个类的代码贴出来。
接受类：
package org.loonsoft.server; import java.io.DataInputStream; import java.io.DataOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.net.ServerSocket; import java.net.Socket; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import javax.swing.JDialog; import javax.swing.JOptionPane; import org.loonsoft.utils.FileProgressBar; import org.loonsoft.utils.FrameUtils; import org.loonsoft.utils.ParamaterUtils; import org.loonsoft.utils.SaveFileDialog; public class ReceiveFileService implements Runnable { private ExecutorService exec = Executors.newCachedThreadPool(); private ServerSocket serverSocket = null; private Socket socket = null; private FrameUtils frame = null; public ReceiveFileService(FrameUtils frame) { this.frame = frame; try { serverSocket = new ServerSocket(ParamaterUtils.getFilePort()); // serverSocket = new ServerSocket(8881); System.out.println("文件监听启动....."); } catch (IOException e) { e.printStackTrace(); } } public void run() { while (true) { try { socket = serverSocket.accept(); // System.out.println(socket.getPort()); exec.execute(new Handler(socket, frame).run()); // socket.close(); // serverSocket.close(); } catch (IOException e) { e.printStackTrace(); } } } // public static void main(String[] args) { // new Thread(new ReceiveFileService()).start(); // } } class Handler { private Socket socket = null; private FrameUtils frame = null; private FileProgressBar bar = null; private final JDialog barDialog = new JDialog(); public Handler(Socket socket, FrameUtils frame) { this.socket = socket; this.frame = frame; } private DataInputStream getDataInputStream() throws IOException { return new DataInputStream(socket.getInputStream()); } private DataOutputStream getDataOutputStream() throws IOException { return new DataOutputStream(socket.getOutputStream()); } private String selectedPath() { return new SaveFileDialog().getPath(frame); } private void runBar(int maxSize) { bar = new FileProgressBar(); bar.setSize(maxSize); barDialog.setLocation(150, 20); barDialog.setTitle("文件接收进度"); barDialog.setSize(250, 50); barDialog.add(bar.getBar()); barDialog.setEnabled(false); barDialog.setVisible(true); new Thread(bar).start(); } public Runnable run() { return new Runnable() { public void run() { try { DataInputStream in = getDataInputStream(); DataOutputStream os = getDataOutputStream(); byte[] data = new byte[1024]; while(in.available()<=0) ;//同步 int len = in.read(data); String[] str = new String(data, 0, len, "utf-8").split(";"); String path = selectedPath(); if (len != -1) path += str[0];//str[0]是文件名加类型 System.out.println(path); os.write("start".getBytes()); os.flush(); File file = new File(path); DataOutputStream out = new DataOutputStream( new FileOutputStream(file)); System.out.println("开始接收....."); int countSize = 0; runBar(Integer.parseInt(str[1]));// 启动文件接受进度条 while ((len = in.read(data)) != -1) { out.write(data, 0, len); countSize += len; bar.setSendSize(countSize); } os.close(); out.flush(); out.close(); in.close(); barDialog.setVisible(false); barDialog.dispose();// 关闭文件进度显示框 JOptionPane.showMessageDialog(frame, "文件接受完成!"); } catch (IOException e) { e.printStackTrace(); } finally { try { socket.close(); System.out.println("关闭...."); } catch (IOException e) { e.printStackTrace(); } } } }; } }
发送类
package org.loonsoft.client;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
import org.loonsoft.utils.ParamaterUtils;
import org.loonsoft.utils.SendFileProgressBar;
public class SendFileService implements Runnable {
private Socket socket = null;
private String path = null;
private SendFileProgressBar bar = null;
public SendFileService(SendFileProgressBar bar)
throws UnknownHostException, IOException {
this.bar = bar;
socket = new Socket(ParamaterUtils.getIp(), ParamaterUtils
.getFilePort());
// socket = new Socket("127.0.0.1", 8881);
}
private DataOutputStream getDataOutputStream() throws IOException {
return new DataOutputStream(socket.getOutputStream());
}
private DataInputStream getDataInputStream() throws IOException {
return new DataInputStream(socket.getInputStream());
}
private String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public void run() {
try {
DataInputStream read = new DataInputStream(new FileInputStream(
new File(getPath())));
bar.setSize(read.available());// 设置文件的总长度
System.out.println(read.available());
DataOutputStream os = getDataOutputStream();
DataInputStream in = getDataInputStream();
String fileName = path.substring(path.lastIndexOf("//") + 1);//获得文件名加类型
System.out.println(fileName);
os.write((fileName + ";" + read.available()).getBytes("utf-8"));//将文件名和文件大小传给接收端
byte[] data = new byte[1024];
int len = in.read(data);
String start = new String(data, 0, len);
int sendCountLen = 0;
if (start.equals("start")) {
new Thread(bar).start();// 启动文件进度条线程
while ((len = read.read(data)) != -1) {
os.write(data, 0, len);
sendCountLen += len;
bar.setSendSize(sendCountLen);
}
os.flush();
os.close();
read.close();
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}