import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;

/**
 * 功能说明: 图片压缩
 * 功能描述: 图片压缩
 */
public class CompressUtils {

  public static byte[] fromBufferedImage2(BufferedImage img, String imagType) throws IOException {
    // 得到指定Format图片的writer
    Iterator<ImageWriter> iter = ImageIO.getImageWritersByFormatName(imagType);
    ImageWriter writer = iter.next();

    //ByteOutputStream bos = new ByteOutputStream();
    File outFile = new File("C:\\Users\\Desktop\\c.jpg");
    try (OutputStream out = new FileOutputStream(outFile)) {
      ImageWriteParam param = writer.getDefaultWriteParam();
      if (param.canWriteCompressed()) {
        param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
        // 设置压缩质量参数
        param.setCompressionQuality(0.5f);
        param.setProgressiveMode(ImageWriteParam.MODE_DISABLED);
        // 指定压缩时使用的色彩模式
        ColorModel colorModel = img.getColorModel();
        param.setDestinationType(new javax.imageio.ImageTypeSpecifier(colorModel,
            colorModel.createCompatibleSampleModel(img.getWidth(), img.getHeight())));
        writer.setOutput(ImageIO.createImageOutputStream(out));
        IIOImage iIamge = new IIOImage(img, null, null);
        writer.write(null, iIamge, param);
        writer.dispose();
      }
      return null;
    }
  }
}