通过TCPIP协议(socket)实现断点续传上传

转载自：传智播客教程

1. 客户端(j2se)。安卓客户端请查看：http://www.cnblogs.com/yangj55/articles/5408518.html

package cn.itcast.net.client;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.io.RandomAccessFile;
import java.net.Socket;

import cn.itcast.utils.StreamTool;

public class SocketClient {

    /**
     * @param args
     */
    public static void main(String[] args) {
        try {                    
        //    Socket socket = new Socket("127.0.0.1", 7878);
            Socket socket = new Socket("127.0.0.1", 7878);
            OutputStream outStream = socket.getOutputStream();            
            String filename = "QQWubiSetup.exe";
            File file = new File(filename);
            String head = "Content-Length="+ file.length() + ";filename="+ filename + ";sourceid=1278916111468\r\n";
            outStream.write(head.getBytes());
            
            PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());    
            String response = StreamTool.readLine(inStream);
            System.out.println(response);
            String[] items = response.split(";");
            String position = items[1].substring(items[1].indexOf("=")+1);
            
            RandomAccessFile fileOutStream = new RandomAccessFile(file, "r");
            fileOutStream.seek(Integer.valueOf(position));
            byte[] buffer = new byte[1024];
            int len = -1;
            int i = 0;
            while( (len = fileOutStream.read(buffer)) != -1){
                outStream.write(buffer, 0, len);
                i++;
                //if(i==10) break;
            }
            fileOutStream.close();
            outStream.close();
            inStream.close();
            socket.close();
        } catch (Exception e) {                    
            e.printStackTrace();
        }

    }
    
}

 

2.服务端：

package cn.itcast.net.server;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PushbackInputStream;
import java.io.RandomAccessFile;
import java.net.ServerSocket;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import cn.itcast.utils.StreamTool;

public class FileServer {
     private ExecutorService executorService;//线程池
     private int port;//监听端口
     private boolean quit = false;//退出
     private ServerSocket server;
     private Map<Long, FileLog> datas = new HashMap<Long, FileLog>();//存放断点数据
     
     public FileServer(int port){
         this.port = port;
         //创建线程池，池中具有(cpu个数*50)条线程
         executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 50);
     }
     /**
      * 退出
      */
     public void quit(){
        this.quit = true;
        try {
            server.close();
        } catch (IOException e) {
        }
     }
     /**
      * 启动服务
      * @throws Exception
      */
     public void start() throws Exception{
         server = new ServerSocket(port);
         while(!quit){
             try {
               Socket socket = server.accept();
               //为支持多用户并发访问，采用线程池管理每一个用户的连接请求
               executorService.execute(new SocketTask(socket));
             } catch (Exception e) {
                 e.printStackTrace();
             }
         }
     }
     
     private final class SocketTask implements Runnable{
        private Socket socket = null;
        public SocketTask(Socket socket) {
            this.socket = socket;
        }
        
        @Override
        public void run() {
            try {
                System.out.println("accepted connection "+ socket.getInetAddress()+ ":"+ socket.getPort());
                PushbackInputStream inStream = new PushbackInputStream(socket.getInputStream());
                //得到客户端发来的第一行协议数据：Content-Length=143253434;filename=xxx.3gp;sourceid=
                //如果用户初次上传文件，sourceid的值为空。
                String head = StreamTool.readLine(inStream);
                System.out.println(head);
                if(head!=null){
                    //下面从协议数据中提取各项参数值
                    String[] items = head.split(";");
                    String filelength = items[0].substring(items[0].indexOf("=")+1);
                    String filename = items[1].substring(items[1].indexOf("=")+1);
                    String sourceid = items[2].substring(items[2].indexOf("=")+1);        
                    long id = System.currentTimeMillis();//生产资源id，如果需要唯一性，可以采用UUID
                    FileLog log = null;
                    if(sourceid!=null && !"".equals(sourceid)){
                        id = Long.valueOf(sourceid);
                        log = find(id);//查找上传的文件是否存在上传记录
                    }
                    File file = null;
                    int position = 0;
                    if(log==null){//如果上传的文件不存在上传记录,为文件添加跟踪记录
                        String path = new SimpleDateFormat("yyyy/MM/dd/HH/mm").format(new Date());
                        File dir = new File("file/"+ path);
                        if(!dir.exists()) dir.mkdirs();
                        file = new File(dir, filename);
                        if(file.exists()){//如果上传的文件发生重名，然后进行改名
                            filename = filename.substring(0, filename.indexOf(".")-1)+ dir.listFiles().length+ filename.substring(filename.indexOf("."));
                            file = new File(dir, filename);
                        }
                        save(id, file);
                    }else{// 如果上传的文件存在上传记录,读取上次的断点位置
                        file = new File(log.getPath());//从上传记录中得到文件的路径
                        if(file.exists()){
                            File logFile = new File(file.getParentFile(), file.getName()+".log");
                            if(logFile.exists()){
                                Properties properties = new Properties();
                                properties.load(new FileInputStream(logFile));
                                position = Integer.valueOf(properties.getProperty("length"));//读取断点位置
                            }
                        }
                    }
                    
                    OutputStream outStream = socket.getOutputStream();
                    String response = "sourceid="+ id+ ";position="+ position+ "\r\n";
                    //服务器收到客户端的请求信息后，给客户端返回响应信息：sourceid=1274773833264;position=0
                    //sourceid由服务生成，唯一标识上传的文件，position指示客户端从文件的什么位置开始上传
                    outStream.write(response.getBytes());
                    
                    RandomAccessFile fileOutStream = new RandomAccessFile(file, "rwd");
                    if(position==0) fileOutStream.setLength(Integer.valueOf(filelength));//设置文件长度
                    fileOutStream.seek(position);//移动文件指定的位置开始写入数据
                    byte[] buffer = new byte[1024];
                    int len = -1;
                    int length = position;
                    while( (len=inStream.read(buffer)) != -1){//从输入流中读取数据写入到文件中
                        fileOutStream.write(buffer, 0, len);
                        length += len;
                        Properties properties = new Properties();
                        properties.put("length", String.valueOf(length));
                        FileOutputStream logFile = new FileOutputStream(new File(file.getParentFile(), file.getName()+".log"));
                        properties.store(logFile, null);//实时记录文件的最后保存位置
                        logFile.close();
                    }
                    if(length==fileOutStream.length()) delete(id);
                    fileOutStream.close();                    
                    inStream.close();
                    outStream.close();
                    file = null;
                    
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally{
                try {
                    if(socket!=null && !socket.isClosed()) socket.close();
                } catch (IOException e) {}
            }
        }
     }
     
     public FileLog find(Long sourceid){
         return datas.get(sourceid);
     }
     //保存上传记录
     public void save(Long id, File saveFile){
         //日后可以改成通过数据库存放
         datas.put(id, new FileLog(id, saveFile.getAbsolutePath()));
     }
     //当文件上传完毕，删除记录
     public void delete(long sourceid){
         if(datas.containsKey(sourceid)) datas.remove(sourceid);
     }
     
     private class FileLog{
        private Long id;
        private String path;
        public Long getId() {
            return id;
        }
        public void setId(Long id) {
            this.id = id;
        }
        public String getPath() {
            return path;
        }
        public void setPath(String path) {
            this.path = path;
        }
        public FileLog(Long id, String path) {
            this.id = id;
            this.path = path;
        }    
     }

}

 

3.服务端界面

package cn.itcast.net.server;

import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.Label;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

public class ServerWindow extends Frame{
    private FileServer s = new FileServer(7878);
    private Label label;
    
    public ServerWindow(String title){
        super(title);
        label = new Label();
        add(label, BorderLayout.PAGE_START);
        label.setText("服务器已经启动");
        this.addWindowListener(new WindowListener() {
            @Override
            public void windowOpened(WindowEvent e) {
                new Thread(new Runnable() {            
                    @Override
                    public void run() {
                        try {
                            s.start();
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }).start();
            }
            
            @Override
            public void windowIconified(WindowEvent e) {
            }
            
            @Override
            public void windowDeiconified(WindowEvent e) {
            }
            
            @Override
            public void windowDeactivated(WindowEvent e) {
            }
            
            @Override
            public void windowClosing(WindowEvent e) {
                 s.quit();
                 System.exit(0);
            }
            
            @Override
            public void windowClosed(WindowEvent e) {
            }
            
            @Override
            public void windowActivated(WindowEvent e) {
            }
        });
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        ServerWindow window = new ServerWindow("文件上传服务端"); 
        window.setSize(300, 300); 
        window.setVisible(true);
    }

}