android 多张图片合成一张

new Thread(new Runnable() {
   @Override
   public void run() {
      Long a =  System.currentTimeMillis();
      File file1 = new File(div,  "1694834497111"+".jpg");
      File file2 = new File(div,  "1694834502113"+".jpg");
      File file3 = new File(div,  "1694835780761"+".jpg");
   
 
      Bitmap bitmap1 = openImage(file1.getAbsolutePath());
      Bitmap bitmap2 = openImage(file2.getAbsolutePath());
      Bitmap bitmap3 = openImage(file3.getAbsolutePath());
      List allbitmap =  new ArrayList();;
      allbitmap.add(bitmap1);
      allbitmap.add(bitmap2);
      allbitmap.add(bitmap3);
      Bitmap big = mergeImages(allbitmap);
      String path = div.getAbsolutePath()+"/ABC.jpg";
      Log.e("log","path"+path);
      saveImage(path,big);
      Log.e("log","time:::" + (System.currentTimeMillis()-a));

   }
}).start();

	public static void saveImage(String path, Bitmap bitmap){
		try {
			BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(path));
			bitmap.compress(Bitmap.CompressFormat.JPEG,100,bos);
			bos.flush();
			bos.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
 
	public static Bitmap openImage(String path){
		Bitmap bitmap = null;
		try {
			BufferedInputStream bis = new BufferedInputStream(new FileInputStream(path));
			bitmap = BitmapFactory.decodeStream(bis);
			bis.close();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
		return bitmap;
	}
 
 
	public Bitmap mergeImages(List<Bitmap> images) {
		int maxWidth = 0;
		int totalHeight = 0;
 
		// 计算合并后图像的宽度和高度
		for (Bitmap image : images) {
			maxWidth = Math.max(maxWidth, image.getWidth());
			totalHeight += image.getHeight();
		}
		Log.e("log","maxWidth"+maxWidth  + "totalHeight"+totalHeight);
		// 创建一个空白的Bitmap，用于绘制合并后的图像
		Bitmap result = Bitmap.createBitmap(maxWidth, totalHeight, Bitmap.Config.ARGB_8888);
 
		// 创建一个Canvas对象，并将其绑定到result Bitmap上
		Canvas canvas = new Canvas(result);
 
		int currentHeight = 0;
 
		// 将每个图像绘制到Canvas上
		for (Bitmap image : images) {
			canvas.drawBitmap(image, 0, currentHeight, null);
			currentHeight += image.getHeight();
		}
 
		return result;
	}