java - How I can convert BufferedImage to a byte array without using files

Question

I'm trying to convert a BufferedImage to an array of bytes but I get every time an exception I have a service that return a bufferImage ,this my code :

BufferedImage bufferedImage = myservice.getImage();
WritableRaster raster = bufferedImage.getRaster();
DataBufferByte data   = (DataBufferByte) raster.getDataBuffer();
 byte[] fileContent = data.getData();

This code thrown an exception :

java.lang.ClassCastException: java.awt.image.DataBufferInt cannot be cast to java.awt.image.DataBufferByte

How I can do this conversion without using files

Answer 1

You can use ByteArrayOutputStream class and write data from BufferedImage object using following code,

BufferedImage image = null; // you have the data in this object
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(image, "fileformat like png or jpg", baos);
baos.flush();
byte[] imageInByte = baos.toByteArray(); // you have the data in byte array
baos.close();

And all of this just in memory without using any disk io or writing to files.