java - 同时启动两个线程但避免使用join after，这是针对android程序的

Question

我的android程序中有两个线程同时启动，用于下载一些数据包。

ServerIP = WifiServer;
Thread thread22 = new Thread (new CallDownloader(fileToReceive, ServerIP, WifiServer, MobileServer));
thread22.start();
ServerIP = MobileServer;
Thread thread23 = new Thread (new CallDownloader(fileToReceive, ServerIP, WifiServer, MobileServer));
thread23.start();

我想同时从两台服务器下载一些文件。如果我在每个线程下使用 thread.joim();

 ServerIP = WifiServer;
        Thread thread22 = new Thread (new CallDownloader(fileToReceive, ServerIP, WifiServer, MobileServer));
        thread22.start();
    thread22.join();
 ServerIP = MobileServer;
        Thread thread23 = new Thread (new CallDownloader(fileToReceive, ServerIP, WifiServer, MobileServer));
        thread23.start();
         thread23.join();

代码不是并行的，而是序列化的。我不想要这个。我知道加入正在等待完成第一个，然后继续另一个。

当我取出 thread.join(); 它下载它想要的任何东西，而不是我想要下载的东西。并且仅使用第一个线程并且不会使用第二个线程。

我怎样才能避免加入？因为我需要线程来调用连接。如果您需要更多详细信息，请告诉我。

这是主要代码。

Queue<String> fileparts = new LinkedList<String>();

    Time = SystemClock.currentThreadTimeMillis();
    long Time2 = System.currentTimeMillis();

    StartTime = Time2;


    int intnumbOfChunks = Integer.parseInt(numbOfChunks);
    intnumbOfChunks = 250;

    for (int i = 0; i < intnumbOfChunks; i++) {

        fileToClaim = "";
        fileToClaim = "bigbang.mp4";
        fileToClaim = String.format("%s.part%06d", fileToClaim, i);

        fileparts.add(fileToClaim);

    }

 int i=0;



 while (!fileparts.isEmpty()) {
fileToReceive = fileparts.peek();

ServerIP = WifiServer;
                Thread thread22 = new Thread (new CallDownloader(fileToReceive, ServerIP, WifiServer, MobileServer));
                thread22.start();
                thread22.start();
                try {
                    thread22.join();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                ServerIP = MobileServer;
                Thread thread23 = new Thread (new CallDownloader(fileToReceive, ServerIP, WifiServer, MobileServer));
                thread23.start();
                try {
                    thread22.join();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
Thread thread3 = new Thread(new Join(fileToReceive));
                thread3.start();            
                try {
                    thread3.join();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }


                fileparts.remove();}

下载线程是

public class Downloader {

    final String fileToReceive;

    boolean fileDownloaded = false;
    Socket clientSocket;

    public Downloader(String fileToReceive) {

        this.fileToReceive = fileToReceive;


    }

    public void download(String ServerIP) {
        //Socket clientSocket = null;
        try {
            System.out.println("kanw connect me ti porta 3248");
            clientSocket = new Socket(ServerIP, 3248);
            System.out.println("egine i sundesi me ti porta 3248");
            System.out.println("stelnw to " + fileToReceive);

            BufferedWriter BuffWriter = new BufferedWriter(
                    new OutputStreamWriter(clientSocket.getOutputStream()));
            BuffWriter.write(fileToReceive + "\n");
            BuffWriter.flush();
            System.out.println("esteila to " + fileToReceive);
            InputStream is = clientSocket.getInputStream();

            File root = Environment.getExternalStorageDirectory();
            System.out.println("dimiourgo to fakelo vid ");
            File dir = new File(root.getAbsolutePath() + "/vid/");
            // File dir = new File (root.getAbsolutePath());
            dir.mkdirs();
            System.out.println("arxizw tin lipsei tou chunk");
            byte[] longBytes = new byte[8];
            readFully(clientSocket, longBytes);
            ByteBuffer bb = ByteBuffer.wrap(longBytes);
            long fileLength = bb.getLong();
            System.out.println("apothikeusi arxeiou");
            // save
            @SuppressWarnings("resource")
            FileOutputStream f = new FileOutputStream(new File(dir,
                    fileToReceive));

            byte[] buffer = new byte[1024];
            int len1 = 0;
            int readBytes = 0;
            while ((len1 = is.read(buffer)) > 0) {
                f.write(buffer, 0, len1);
                readBytes += len1;

            }

            if (readBytes == fileLength) {
                this.fileDownloaded = true;
            }
            System.out.println("Receiving the file " + fileToReceive);

            System.out.println("File Recieved");

        } catch (IOException ex) {
            System.out.println("Client stopped");
            ex.printStackTrace();

        } finally {
            try {
                if (clientSocket != null && !clientSocket.isClosed()) {
                    clientSocket.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private void readFully(Socket clientSocket, byte[] buffer)
            throws IOException {
        System.out.println("readfully");
        InputStream inputStream = clientSocket.getInputStream();
        int remaining = buffer.length;
        int read = 0;
        while (remaining > 0) {

            read = inputStream.read(buffer, buffer.length - remaining,  remaining);

            if (read < 0) {
                throw new IOException();
            }
            remaining -= read;
        }
        System.out.println("exit");
    }


    public boolean IsDownloaded() {

        return this.fileDownloaded;
    }


}

CallDownloader 类是线程

public void run() {


        System.out.println("connecting tou "+ServerIP);
        Downloader d = new Downloader(fileToReceive);
        //Downloader1 d1 = new Downloader1(fileToReceive);
        d.download(ServerIP);
}