图片压缩

/**
* ��������ͼ��
*/
package utils;

/**
* @author advance
*
*/
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;

public class ThumbnailGenerator {
public static void main(String[] args) throws Exception {
transform("C:\Users\Administrator\vspider\files\20190111\image\jpg\0a08179283e02baefc529affd2dd30fe.jpg","C:\Users\Administrator\Desktop\新建文件夹 (2)\aaa.jpg",200,300,1000);
}

public static void transform(String originalFile, String thumbnailFile, int thumbWidth, int thumbHeight, int quality) throws Exception
{
Image image = javax.imageio.ImageIO.read(new File(originalFile));

double thumbRatio = (double)thumbWidth / (double)thumbHeight;
int imageWidth = image.getWidth(null);
int imageHeight = image.getHeight(null);
double imageRatio = (double)imageWidth / (double)imageHeight;
if (thumbRatio < imageRatio)
{
thumbHeight = (int)(thumbWidth / imageRatio);
}
else
{
thumbWidth = (int)(thumbHeight * imageRatio);
}

if(imageWidth < thumbWidth && imageHeight < thumbHeight)
{
thumbWidth = imageWidth;
thumbHeight = imageHeight;
}
else if(imageWidth < thumbWidth)
thumbWidth = imageWidth;
else if(imageHeight < thumbHeight)
thumbHeight = imageHeight;

BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = thumbImage.createGraphics();
graphics2D.setBackground(Color.WHITE);
graphics2D.setPaint(Color.WHITE);
graphics2D.fillRect(0, 0, thumbWidth, thumbHeight);
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);

javax.imageio.ImageIO.write(thumbImage, "JPG", new File(thumbnailFile));
}
}