How to write a Base64-encoded image to file?
I have encoded an image to a string using Base64. First, I read the file, then convert it to a byte array and then apply Base64 encoding to convert the image to a string.
Now my problem is how to decode it.
byte dearr[] = Base64.decodeBase64(crntImage);
File outF = new File("c:/decode/abc.bmp");
BufferedImage img02 = ImageIO.write(img02, "bmp", outF);
The variable crntImage
contains the string representation of the image.
Base64
APIbyte[] decodedImg = Base64.getDecoder()
.decode(encodedImg.getBytes(StandardCharsets.UTF_8));
Path destinationFile = Paths.get("/path/to/imageDir", "myImage.jpg");
Files.write(destinationFile, decodedImg);
If your encoded image starts with something like data:image/png;base64,iVBORw0...
, you'll have to remove the part. See this answer for an easy way to do that.
Try this:
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
public class WriteImage
{
public static void main( String[] args )
{
BufferedImage image = null;
try {
URL url = new URL("URL_IMAGE");
image = ImageIO.read(url);
ImageIO.write(image, "jpg",new File("C:\\out.jpg"));
ImageIO.write(image, "gif",new File("C:\\out.gif"));
ImageIO.write(image, "png",new File("C:\\out.png"));
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Done");
}
}
No need to use BufferedImage, as you already have the image file in a byte array
byte dearr[] = Base64.decodeBase64(crntImage);
FileOutputStream fos = new FileOutputStream(new File("c:/decode/abc.bmp"));
fos.write(dearr);
fos.close();
Other option using apache-commons:
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.io.FileUtils;
...
File file = new File( "path" );
byte[] bytes = Base64.decodeBase64( "base64" );
FileUtils.writeByteArrayToFile( file, bytes );
import java.util.Base64;
.... Just making it clear that this answer uses the java.util.Base64 package, without using any third-party libraries.
String crntImage=<a valid base 64 string>
byte[] data = Base64.getDecoder().decode(crntImage);
try( OutputStream stream = new FileOutputStream("d:/temp/abc.pdf") )
{
stream.write(data);
}
catch (Exception e)
{
System.err.println("Couldn't write to file...");
}
Source: Stackoverflow.com