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一个基于Java Socket协议之上文件传输的完整示例,基于TCP通信完成。
除了基于TCP的二进制文件传输,还演示了JAVA Swing的一些编程技巧,Demo程序
实现主要功能有以下几点:
1. 基于Java Socket的二进制文件传输(包括图片,二进制文件,各种文档work,
PDF)
2. SwingWorker集合JProgressBar显示实时传输/接受完成的百分比
3. 其它一些Swing多线程编程技巧
首先来看一下整个Dome的Class之间的关系图:
下面按照上图来详细解释各个类的功能与代码实现:
服务器端:
FileTransferServer类的功能首先是在端口9999创建一个服务器套接字并
开始监听连接。相关代码如下:
- private void startServer(int port) {
- try {
- serverSocket = new ServerSocket(port);
- System.out.println("Server started at port :" + port);
- while(true) {
- Socket client = serverSocket.accept(); // blocked & waiting for income socket
- System.out.println("Just connected to " + client.getRemoteSocketAddress());
- FileReceiveTask task = new FileReceiveTask(client);
- bar.setValue(0); // reset it now
- task.addPropertyChangeListener(new PropertyChangeListener() {
- public void propertyChange(PropertyChangeEvent evt) {
- if ("progress".equals(evt.getPropertyName())) {
- bar.setValue((Integer) evt.getNewValue());
- }
- }
- });
- task.execute();
- }
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
关于PropertyChangeListener, Java提供了一个非常有力的工具类来
监控任意Bean Model的数据改变,程序通过添加该监听器实现对
SwingWorker的progress属性值改变的事件捕获,然后更新JProgressBar
实例对象,实现了UI的刷新。FileTransferServer类的完整源代码如下:
- package com.gloomyfish.socket.tutorial.filetransfer;
- import java.awt.BorderLayout;
- import java.awt.FlowLayout;
- import java.awt.event.ActionEvent;
- import java.awt.event.ActionListener;
- import java.beans.PropertyChangeEvent;
- import java.beans.PropertyChangeListener;
- import java.io.IOException;
- import java.net.ServerSocket;
- import java.net.Socket;
- import javax.swing.BoxLayout;
- import javax.swing.JButton;
- import javax.swing.JFrame;
- import javax.swing.JOptionPane;
- import javax.swing.JPanel;
- import javax.swing.JProgressBar;
- public class FileTransferServer extends JFrame implements ActionListener {
- /**
- *
- */
- public final static String START_SVR = "Start";
- public final static String SHUT_DOWN_SVR = "Shut Down";
- public final static String END_FLAG = "EOF";
- private static final long serialVersionUID = 1L;
- private ServerSocket serverSocket;
- private JButton startBtn;
- private JProgressBar bar;
- public FileTransferServer() {
- super("File Server");
- initComponent();
- setupListener();
- }
- private void setupListener() {
- startBtn.addActionListener(this);
- }
- private void initComponent() {
- startBtn = new JButton(START_SVR);
- JPanel progressPanel = new JPanel();
- progressPanel.setLayout(new BoxLayout(progressPanel, BoxLayout.Y_AXIS));
- bar = new JProgressBar();
- bar.setMinimum(0);
- bar.setMaximum(100);
- progressPanel.add(bar);
- getContentPane().setLayout(new BorderLayout());
- JPanel btnPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
- btnPanel.add(startBtn);
- getContentPane().add(btnPanel, BorderLayout.SOUTH);
- getContentPane().add(progressPanel, BorderLayout.CENTER);
- }
- private void startServer(int port) {
- try {
- serverSocket = new ServerSocket(port);
- System.out.println("Server started at port :" + port);
- while(true) {
- Socket client = serverSocket.accept(); // blocked & waiting for income socket
- System.out.println("Just connected to " + client.getRemoteSocketAddress());
- FileReceiveTask task = new FileReceiveTask(client);
- bar.setValue(0); // reset it now
- task.addPropertyChangeListener(new PropertyChangeListener() {
- public void propertyChange(PropertyChangeEvent evt) {
- if ("progress".equals(evt.getPropertyName())) {
- bar.setValue((Integer) evt.getNewValue());
- }
- }
- });
- task.execute();
- }
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- public void showSuccess() {
- bar.setValue(100);
- JOptionPane.showMessageDialog(this, "file received successfully!");
- }
- @Override
- public void actionPerformed(ActionEvent e) {
- if(START_SVR.equals(e.getActionCommand())) {
- Thread startThread = new Thread(new Runnable() {
- public void run() {
- startServer(9999);
- }
- });
- startThread.start();
- startBtn.setEnabled(false);
- } else if(SHUT_DOWN_SVR.equals(e.getActionCommand())) {
- } else {
- // do nothing...
- }
- }
- public static void main(String[] args) {
- FileTransferServer server = new FileTransferServer();
- server.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
- server.setSize(400, 400);
- server.setResizable(false);
- server.setVisible(true);
- }
- }
FileReceiveTask是服务器端的文件接受类:
首先从建立的TCP流中得到文件名与文件大小,然后开始接受文件内容字节
并写入创建的文件对象流中,最后验证文件大小与写入的字节流是否相等
最后发送一条消息到文件发送方,告诉对方文件传输完成,可以关闭TCP流。
该类的完整源代码如下:
- package com.gloomyfish.socket.tutorial.filetransfer;
- import java.io.BufferedOutputStream;
- import java.io.BufferedWriter;
- import java.io.DataInputStream;
- import java.io.File;
- import java.io.FileOutputStream;
- import java.io.OutputStreamWriter;
- import java.net.Socket;
- import javax.swing.SwingWorker;
- public class FileReceiveTask extends SwingWorker<Integer, Object> {
- private Socket _mSocket;
- public FileReceiveTask(Socket client) {
- this._mSocket = client;
- }
- @Override
- protected Integer doInBackground() throws Exception {
- // get file meta information
- DataInputStream input = new DataInputStream(_mSocket.getInputStream());
- String fileName = input.readUTF();
- int fileLength = (int)input.readLong(); // number of total bytes
- File file = new File("C:\\Users\\fish\\Downloads" + File.separator + fileName);
- BufferedOutputStream output = new BufferedOutputStream(new FileOutputStream(file));
- System.out.println("Received File Name = " + fileName);
- System.out.println("Received File size = " + fileLength/1024 + "KB");
- // start to receive the content of the file and write them
- byte[] content = new byte[2048];
- int offset = 0;
- int numReadBytes = 0;
- while(offset < fileLength && (numReadBytes = input.read(content)) > 0) {
- output.write(content, 0, numReadBytes);
- float precent = 100.0f * ((float)offset)/((float)fileLength);
- setProgress((int)precent);
- offset += numReadBytes;
- }
- System.out.println("numReadBytes = " + numReadBytes);
- if(offset < fileLength) {
- numReadBytes = input.read(content);
- System.out.println("numReadBytes = " + numReadBytes);
- System.out.println("File content error at server side");
- } else {
- System.out.println("File Receive Task has done correctly");
- }
- setProgress(100);
- // tell client to close the socket now, we already receive the file successfully!!
- BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(_mSocket.getOutputStream()));
- bufferedWriter.write("DONE\r\n");
- bufferedWriter.flush();
- // close the file and socket
- output.close();
- _mSocket.close();
- return 100;
- }
- }
客户端:
FileTransferClient是客户端UI类,用来实现到服务端的连接,然后选择
要传输的文件(图片,PDF,Word文档等各种二进制文件)。如果没有
输入服务器信息,会弹出提示要求输入。端口已经指定为:9999
【send File】按钮会打开文件选择框,用户选择要传输文件以后,创建
FileTransferTask线程,并开始执行文件传送。客户端UI代码如下:
- package com.gloomyfish.socket.tutorial.filetransfer;
- import java.awt.BorderLayout;
- import java.awt.FlowLayout;
- import java.awt.GridLayout;
- import java.awt.event.ActionEvent;
- import java.awt.event.ActionListener;
- import java.beans.PropertyChangeEvent;
- import java.beans.PropertyChangeListener;
- import java.io.File;
- import java.net.InetSocketAddress;
- import java.net.SocketAddress;
- import javax.swing.BorderFactory;
- import javax.swing.BoxLayout;
- import javax.swing.JButton;
- import javax.swing.JFileChooser;
- import javax.swing.JFrame;
- import javax.swing.JLabel;
- import javax.swing.JOptionPane;
- import javax.swing.JPanel;
- import javax.swing.JProgressBar;
- import javax.swing.JTextField;
- /**
- * 我一般写英文注释,偶尔我也会写中文注释,只是觉得写英文
- * 注释跟代码比较统一,无他。
- *
- * @Date 2012-11-30
- * @author fish
- *
- */
- public class FileTransferClient extends JFrame implements ActionListener {
- /**
- *
- */
- private static final long serialVersionUID = 1L;
- public final static String SEND_CMD = "Send File";
- public final static int MINIMUM = 0;
- public final static int MAXIMUM = 100;
- // public final static String CONNECT_CMD = "Connect";
- private JButton sendFileBtn;
- private JTextField serverField;
- private JTextField portField;
- private JProgressBar bar;
- public FileTransferClient() {
- super("File Transfer Client");
- initComponents();
- }
- private void initComponents() {
- getContentPane().setLayout(new BorderLayout());
- JPanel progressPanel = new JPanel();
- progressPanel.setLayout(new BoxLayout(progressPanel, BoxLayout.Y_AXIS));
- bar = new JProgressBar();
- progressPanel.add(bar);
- bar.setMinimum(MINIMUM);
- bar.setMaximum(MAXIMUM);
- JPanel serverSettingPanel = new JPanel();
- serverSettingPanel.setLayout(new GridLayout(2,2,5,5));
- serverSettingPanel.setBorder(BorderFactory.createTitledBorder("Server Setting"));
- serverField = new JTextField();
- portField = new JTextField();
- serverSettingPanel.add(new JLabel("Server IP/Host:"));
- serverSettingPanel.add(serverField);
- serverSettingPanel.add(new JLabel("Server Port:"));
- serverSettingPanel.add(portField);
- sendFileBtn = new JButton(SEND_CMD);
- JPanel btnPanel = new JPanel();
- btnPanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
- btnPanel.add(sendFileBtn);
- getContentPane().add(serverSettingPanel, BorderLayout.NORTH);
- getContentPane().add(btnPanel, BorderLayout.SOUTH);
- getContentPane().add(progressPanel, BorderLayout.CENTER);
- sendFileBtn.addActionListener(this);
- }
- @Override
- public void actionPerformed(ActionEvent e) {
- String command = e.getActionCommand();
- if(command.equals(SEND_CMD)) {
- if(checkNull()) {
- JOptionPane.showMessageDialog(this, "Please enter server host and port in order to set up the connection!");
- return;
- }
- JFileChooser chooser = new JFileChooser();
- int status = chooser.showOpenDialog(null);
- if (status == JFileChooser.APPROVE_OPTION) {
- File f = chooser.getSelectedFile();
- SocketAddress address = new InetSocketAddress(getServer(), getPort());
- FileTransferTask task = new FileTransferTask(f, address, this);
- bar.setValue(0);
- task.addPropertyChangeListener(new PropertyChangeListener() {
- public void propertyChange(PropertyChangeEvent evt) {
- if ("progress".equals(evt.getPropertyName())) {
- bar.setValue((Integer) evt.getNewValue());
- }
- }
- });
- task.execute(); // 异步task执行
- }
- } else {
- // do nothing
- }
- }
- public void showSuccess() {
- bar.setValue(100);
- JOptionPane.showMessageDialog(this, "file send successfully!");
- }
- public String getServer() {
- return serverField.getText().trim();
- }
- public int getPort() {
- return Integer.parseInt(portField.getText().trim());
- }
- /**
- * make sure the UI already have some correct input information here!!!
- * @return
- */
- private boolean checkNull() {
- String serverName = serverField.getText();
- String port = portField.getText();
- if(serverName == null || serverName.length() == 0 || port == null || port.length() == 0) {
- return true;
- }
- try {
- Integer.parseInt(port); // try to parse it as server port number , validation code.
- } catch(NumberFormatException ne) {
- ne.printStackTrace();
- return true;
- }
- return false;
- }
- public static void main(String[] args) {
- FileTransferClient client = new FileTransferClient();
- client.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
- client.setSize(400, 400);
- client.setResizable(false);
- // client.pack();
- client.setVisible(true);
- }
- }
FileTransferTask实现的功能主要有:
1. 发送文件meta信息到接受方(文件名与文件大小)
2. 读取文件内容字节写入Socket字节流中,发送到接受方
3. 从Socket字节流中读取对方接受完成通知信息,调用弹出文件传输成功信息
该类完全源代码如下:
- package com.gloomyfish.socket.tutorial.filetransfer;
- import java.io.BufferedInputStream;
- import java.io.BufferedReader;
- import java.io.DataInputStream;
- import java.io.DataOutputStream;
- import java.io.File;
- import java.io.FileInputStream;
- import java.io.IOException;
- import java.io.InputStreamReader;
- import java.net.Socket;
- import java.net.SocketAddress;
- import javax.swing.SwingWorker;
- public class FileTransferTask extends SwingWorker<Integer, Object> {
- private File selectedFile;
- private Socket mSocket;
- private SocketAddress address;
- private FileTransferClient parent;
- public FileTransferTask(File file, SocketAddress address, FileTransferClient owner /*, JProgressBar progress*/) {
- this.address = address;
- this.selectedFile = file;
- mSocket = new Socket();
- this.parent = owner;
- }
- @Override
- protected Integer doInBackground() throws Exception {
- // Get the size of the file
- long length = selectedFile.length();
- if (length > Integer.MAX_VALUE) {
- throw new IOException("Could not completely read file " + selectedFile.getName() + " as it is too long (" + length + " bytes, max supported " + Integer.MAX_VALUE + ")");
- }
- mSocket.connect(address);
- // Create the byte array to hold the file data
- mSocket.setSoLinger(true, 60);
- DataOutputStream dout = new DataOutputStream(mSocket.getOutputStream());
- // now we start to send the file meta info.
- dout.writeUTF(selectedFile.getName());
- dout.writeLong(length);
- dout.flush();
- // end comment
- FileDataPackage pData = new FileDataPackage();
- DataInputStream is = new DataInputStream(new FileInputStream(selectedFile));
- byte[] bytes = new byte[2048];
- // Read in the bytes
- int offset = 0;
- int numRead = 0;
- int fsize = (int)length;
- while (offset < fsize && (numRead=is.read(bytes, 0, bytes.length)) >= 0) {
- pData.setData(bytes, numRead);
- dout.write(pData.getPackageData(), 0, pData.getPackageData().length);
- dout.flush();
- offset += numRead;
- float precent = 100.0f * ((float)offset)/((float)fsize);
- setProgress((int)precent);
- }
- System.out.println("total send bytes = " + offset);
- // Ensure all the bytes have been read in
- if (offset < fsize) {
- throw new IOException("Could not completely transfer file " + selectedFile.getName());
- }
- mSocket.shutdownOutput();
- // receive the file transfer successfully message from connection
- BufferedInputStream streamReader = new BufferedInputStream(mSocket.getInputStream());
- BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(streamReader));
- String doneMsg = bufferedReader.readLine();
- if("DONE".equals(doneMsg)) {
- parent.showSuccess();
- }
- // Close the file input stream
- setProgress(100);
- // dout.close();
- mSocket.close();
- is.close();
- System.out.println("close it now......");
- return 100;
- }
- }
数据包类如下,不解释!
- package com.gloomyfish.socket.tutorial.filetransfer;
- /**
- * this is very simple file transfer protocol over TCP socket
- * @date 2012-12-01
- * @author zhigang jia
- *
- */
- public class FileDataPackage {
- private int dataLength; // 数据包中数据长度,两个字节
- private byte[] databuff; // 数据包中数据,meici最大不超过2048字节
- public final static byte[] EOF = new byte[]{'E', 'O','F'};
- public FileDataPackage() {
- dataLength = 0;
- databuff = new byte[2048];
- }
- public byte[] getPackageData() {
- byte[] pData = new byte[dataLength];
- // end comment
- System.arraycopy(databuff, 0, pData, 0, dataLength);
- return pData;
- }
- public void setData(byte[] data, int bsize) {
- dataLength = bsize;
- for(int i=0; i<databuff.length; i++) {
- if(i<bsize) {
- databuff[i] = data[i];
- } else {
- databuff[i] = ' ';
- }
- }
- }
- }
每次发送的最大字节数为2048个字节。程序最终运行效果如下(win7 + JDK6u30):
觉得不错,请顶一下啊,谢谢!