com.sksamuel.scrimage.nio.ImageIOReader Maven / Gradle / Ivy

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JVM Image Library
There is a newer version: 4.2.0
package com.sksamuel.scrimage.nio;

import com.sksamuel.scrimage.ImmutableImage;

import javax.imageio.ImageIO;
import javax.imageio.ImageReadParam;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.stream.ImageInputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class ImageIOReader implements ImageReader {

   private final List readers;

   public ImageIOReader() {
      readers = Collections.emptyList();
   }

   public ImageIOReader(List readers) {
      this.readers = readers;
   }

   private ImmutableImage tryLoad(javax.imageio.ImageReader reader, ImageInputStream iis, Rectangle rectangle) throws IOException {
      reader.setInput(iis);

      ImageReadParam params = reader.getDefaultReadParam();
      Iterator imageTypes = reader.getImageTypes(0);
      if (imageTypes.hasNext()) {
         ImageTypeSpecifier imageTypeSpecifier = imageTypes.next();
         params.setDestinationType(imageTypeSpecifier);
      }
      if (rectangle != null) {
         params.setSourceRegion(rectangle);
      }

      BufferedImage bufferedImage = reader.read(0, params);
      return ImmutableImage.wrapAwt(bufferedImage);
   }

   @Override
   public ImmutableImage read(byte[] bytes, Rectangle rectangle) throws IOException {

      if (bytes == null)
         throw new IOException("bytes cannot be null");

      ImageInputStream iis = ImageIO.createImageInputStream(new ByteArrayInputStream(bytes));
      if (iis == null)
         throw new IOException("No ImageInputStream supported this image format");

      Iterator iter;
      if (readers.isEmpty())
         iter = ImageIO.getImageReaders(iis);
      else
         iter = readers.iterator();

      List attempts = new ArrayList<>();
      while (iter.hasNext()) {
         try {
            return tryLoad(iter.next(), iis, rectangle);
         } catch (Exception e) {
            attempts.add(e.getMessage());
         }
      }

      if (attempts.isEmpty())
         throw new IOException("No javax.imageio.ImageReader supported this image format");
      else
         throw new IOException("No javax.imageio.ImageReader supported this image format; tried " + attempts.size() + " readers; errors=" + attempts);
   }

   @Override
   public String toString() {
      return "com.sksamuel.scrimage.nio.ImageIOReader (delegates to the JDK javax.imageio readers)";
   }
}