ImageIO.write没有保存为gif,但适用于jpgs和pngs？

public static boolean write(RenderedImage im, String formatName, File output)

import org.apache.commons.imaging.ImageWriteException;
import org.apache.commons.imaging.Imaging;
import org.apache.commons.imaging.common.ImageMetadata;
import org.apache.commons.imaging.formats.gif.GifImageMetadata;
import org.apache.commons.imaging.formats.gif.GifParameters;

import java.awt.image.RenderedImage;
import java.io.File;
import java.io.IOException;

public class ImageIOUtil {
    public static void writeGif(RenderedImage image, File file) throws IOException, ImageWriteException {
        ImageMetadata metadata = new GifImageMetadata();
        GifParameters params = new GifParameters();
        Imaging.writeImage(image, file, params, metadata);
    }
}