利用java socket传输文件

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();
}

}

}
}