欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  Java

Java上传图片后的缩放

程序员文章站 2022-05-07 13:35:14
...
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.ConvolveOp;
import java.awt.image.Kernel;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
  
import org.apache.commons.fileupload.FileItem;
import org.apache.log4j.Logger;
  
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
  
public class ImageUtil {
    /**
     * Logger for this class
     */
    private static final Logger logger = Logger.getLogger(ImageUtil.class);
  
    public void imageScale(String srcFilePath, String targetFilePath,
            int width, int height) {
        this.imageScale(new File(srcFilePath), new File(targetFilePath), width,
                height);
    }
  
    public void imageScale(File srcFile, File targetFile, int width, int height) {
        try {
            Image image = javax.imageio.ImageIO.read(srcFile);
  
            image = image.getScaledInstance(width, height,
                    Image.SCALE_AREA_AVERAGING);
            // Make a BufferedImage from the Image.
            BufferedImage mBufferedImage = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics2D g2 = mBufferedImage.createGraphics();            
  
            g2.drawImage(image, 0, 0, width, height, Color.white, null);
            g2.dispose();
  
            float[] kernelData2 = { -0.125f, -0.125f, -0.125f, -0.125f, 2,
                    -0.125f, -0.125f, -0.125f, -0.125f };
            Kernel kernel = new Kernel(3, 3, kernelData2);
            ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);
            mBufferedImage = cOp.filter(mBufferedImage, null);
  
            File targetDir = targetFile.getParentFile();
            if (!targetDir.exists())
                targetDir.mkdirs();
  
            FileOutputStream out = new FileOutputStream(targetFile);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(mBufferedImage);
            out.close();
        } catch (Exception e) {
            logger.error(
                    "imageScale(String, String, int, int) - 图片压缩出错 - srcFilePath="
                            + srcFile.getPath() + ", targeFilePath="
                            + targetFile.getPath() + ", width=" + width
                            + ", height=" + height, e);
        }
    }
  
    public void imageScale(FileItem fileItem, String targetFilePath, int width,
            int height) {
        try {
            InputStream input = fileItem.getInputStream();
            Image image = javax.imageio.ImageIO.read(input);
  
            image = image.getScaledInstance(width, height,
                    Image.SCALE_AREA_AVERAGING);
            BufferedImage mBufferedImage = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            Graphics2D g2 = mBufferedImage.createGraphics();
  
            g2.drawImage(image, 0, 0, width, height, Color.white, null);
            g2.dispose();
  
            float[] kernelData2 = { -0.125f, -0.125f, -0.125f, -0.125f, 2,
                    -0.125f, -0.125f, -0.125f, -0.125f };
            Kernel kernel = new Kernel(3, 3, kernelData2);
            ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);
            mBufferedImage = cOp.filter(mBufferedImage, null);
  
            File target = new File(targetFilePath);
            File targetDir = target.getParentFile();
            if (!targetDir.exists())
                targetDir.mkdirs();
  
            FileOutputStream out = new FileOutputStream(targetFilePath);
            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
            encoder.encode(mBufferedImage);
            out.close();
            input.close();
        } catch (Exception e) {
            logger.error(
                    "imageScale(String, String, int, int) - 图片压缩出错 - fileItem="
                            + fileItem.getName() + ", targetFilePath="
                            + targetFilePath + ", width=" + width + ", height="
                            + height, e);
        }
    }
      
    public static void main(String[] args) {
        ImageUtil iu=new ImageUtil();
        iu.imageScale("c:/uploadFiles/191540095661.jpg", "c:/uploadFiles/t.jpg", 270, 220);
    }
}