java IO一些点

1、BufferedImage->byte[]

BufferedImage outputImage = new BufferedImage(w, h,BufferedImage.TYPE_INT_RGB);
ByteArrayOutputStream out = new ByteArrayOutputStream();
ImageIO.write(outputImage,"jpg",out);
return out.toByteArray();
//或再转成InputStream
//InputStream sbs = new ByteArrayInputStream(out.toByteArray()); 

2、byte[]->BufferedImage

ByteArrayOutputStream swapStream = new ByteArrayOutputStream();
byte[] buff = new byte[10485760]; //暂时上限10M
int rc = 0;
while ((rc = fileStream.read(buff, 0, 10485760)) > 0) {
      swapStream.write(buff, 0, rc);
}
ByteArrayInputStream in = new ByteArrayInputStream(swapStream.toByteArray());   
BufferedImage image = ImageIO.read(in);//转换

3、