中断使用dataInputStream进行的下载

使用DataInputStream进行下载时，可以通过使用线程来实现中断下载的功能。下面是一个示例代码：

import java.io.*;
import java.net.URL;

public class DownloadManager {
    private static final int BUFFER_SIZE = 4096;

    public static void main(String[] args) {
        String fileURL = "http://example.com/file.zip";
        String saveDir = "/path/to/save/directory/";

        try {
            URL url = new URL(fileURL);
            InputStream inputStream = url.openStream();
            DataInputStream dataInputStream = new DataInputStream(new BufferedInputStream(inputStream));

            FileOutputStream fileOutputStream = new FileOutputStream(saveDir + getFileName(fileURL));

            byte[] buffer = new byte[BUFFER_SIZE];
            int bytesRead;
            while ((bytesRead = dataInputStream.read(buffer)) != -1) {
                fileOutputStream.write(buffer, 0, bytesRead);
            }

            fileOutputStream.close();
            dataInputStream.close();

            System.out.println("Download completed");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static String getFileName(String fileURL) {
        String fileName = "";

        int slashIndex = fileURL.lastIndexOf("/");
        int dotIndex = fileURL.lastIndexOf(".");

        if (dotIndex >= 0 && dotIndex < fileURL.length() - 1) {
            fileName = fileURL.substring(slashIndex + 1);
        }

        return fileName;
    }
}

如果需要中断下载，可以在while循环中加入一个判断条件，例如检查某个标志位的状态。当判断条件为真时，跳出循环，从而中断下载。

boolean shouldInterrupt = false;

// ...

while ((bytesRead = dataInputStream.read(buffer)) != -1) {
    if (shouldInterrupt) {
        break;
    }
    fileOutputStream.write(buffer, 0, bytesRead);
}

当shouldInterrupt为true时，循环会被中断，下载也会停止。