java实现切图并且判断图片是不是纯色/彩色图片

  public static void imageCut(int x, int y, int width, int height, String sourcePath, String descpath) {     FileInputStream is = null;     ImageInputStream iis = null;     try {       is = new FileInputStream(sourcePath);       String fileSuffix = sourcePath.substring(sourcePath.lastIndexOf(".") + 1);       Iterator<ImageReader> it = ImageIO.getImageReadersByFormatName(fileSuffix);       ImageReader reader = it.next();       iis = ImageIO.createImageInputStream(is);       reader.setInput(iis, true);       ImageReadParam param = reader.getDefaultReadParam();       Rectangle rect = new Rectangle(x, y, width, height);       param.setSourceRegion(rect);       BufferedImage bi = reader.read(0, param);       ImageIO.write(bi, fileSuffix, new File(descpath));     } catch (Exception ex) {       ex.printStackTrace();     } finally {       if (is != null) {         try {           is.close();         } catch (IOException e) {           e.printStackTrace();         }         is = null;       }       if (iis != null) {         try {           iis.close();         } catch (IOException e) {           e.printStackTrace();         }         iis = null;       }     }   }