如何在Android中将位图转换为jpeg文件？

用这个:

Bitmap bmp = null;
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] byteArray = stream.toByteArray();

为此你可以使用这个:

FileInputStream fileInputStream = null;

File file = new File("yourfile");

byteArray = new byte[(int) file.length()];

try {
    //convert file into array of bytes
    fileInputStream = new FileInputStream(file);
    fileInputStream.read(bFile);
    fileInputStream.close();

    //convert array of bytes into file
    FileOutputStream fileOuputStream =
            new FileOutputStream("C:\\testing2.txt");
    fileOuputStream.write(bFile);
    fileOuputStream.close();

    System.out.println("Done");
} catch (Exception e) {
    e.printStackTrace();
}

而且有关更多信息,请点击此处