Android 中使用多线程实现文件上传的代码

以下是一个在 Android 中使用多线程实现文件上传的示例代码：

import android.os.Environment;
import android.util.Log;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class MultiThreadUploader {

    private static final String TAG = "MultiThreadUploader";
    private static final int BUFFER_SIZE = 8192;
    private String uploadUrl;
    private File fileToUpload;
    private int threadCount;

    public MultiThreadUploader(String uploadUrl, File fileToUpload, int threadCount) {
        this.uploadUrl = uploadUrl;
        this.fileToUpload = fileToUpload;
        this.threadCount = threadCount;
    }

    public void startUpload() {
        try {
            long fileLength = fileToUpload.length();
            long partSize = fileLength / threadCount;
            ExecutorService executor = Executors.newFixedThreadPool(threadCount);

            for (int i = 0; i < threadCount; i++) {
                long start = i * partSize;
                long end = (i == threadCount - 1)? fileLength - 1 : (i + 1) * partSize - 1;
                UploadTask task = new UploadTask(start, end, i);
                executor.execute(task);
            }

            executor.shutdown();
            while (!executor.isTerminated()) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }

            Log.d(TAG, "Upload completed.");

        } catch (IOException e) {
            Log.e(TAG, "Upload error: " + e.getMessage());
        }
    }

    private class UploadTask implements Runnable {

        private long start;
        private long end;
        private int taskId;

        public UploadTask(long start, long end, int taskId) {
            this.start = start;
            this.end = end;
            this.taskId = taskId;
        }

        @Override
        public void run() {
            try {
                URL url = new URL(uploadUrl);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setRequestMethod("POST");
                connection.setDoOutput(true);
                connection.setRequestProperty("Content-Range", "bytes " + start + "-" + end + "/" + fileToUpload.length());

                OutputStream outputStream = connection.getOutputStream();
                FileInputStream inputStream = new FileInputStream(fileToUpload);
                inputStream.skip(start);

                byte[] buffer = new byte[BUFFER_SIZE];
                int bytesRead;
                while ((bytesRead = inputStream.read(buffer))!= -1 && start <= end) {
                    outputStream.write(buffer, 0, bytesRead);
                    start += bytesRead;
                }

                inputStream.close();
                outputStream.close();

                int responseCode = connection.getResponseCode();
                if (responseCode == HttpURLConnection.HTTP_OK) {
                    Log.d(TAG, "Task " + taskId + " completed successfully.");
                } else {
                    Log.e(TAG, "Task " + taskId + " failed with response code: " + responseCode);
                }

            } catch (IOException e) {
                Log.e(TAG, "Task " + taskId + " error: " + e.getMessage());
            }
        }
    }

    public static void main(String[] args) {
        String uploadUrl = "http://your-server-url.com/upload";
        File fileToUpload = new File(Environment.getExternalStorageDirectory(), "your_file_to_upload.txt");
        int threadCount = 3;

        MultiThreadUploader uploader = new MultiThreadUploader(uploadUrl, fileToUpload, threadCount);
        uploader.startUpload();
    }
}

请注意：

1. 这只是一个示例代码，在实际应用中，你可能需要处理更多的错误情况，如网络连接问题、服务器错误响应等。
2. 在 Android 应用中，确保你有适当的权限来访问外部存储（如果文件在外部存储上）和进行网络操作。并且应该在主线程之外的线程中执行网络操作，以避免阻塞主线程。