import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
public class Snippet {
/**
* 創建圖片縮略圖(等比縮放)
*
* @param src
* 源圖片文件完整路徑
* @param dist
* 目標圖片文件完整路徑
* @param width
* 縮放的寬度
* @param height
* 縮放的高度
*/
public static void createThumbnail(String src, String dist, float width,
float height) {
try {
File srcfile = new File(src);
if (!srcfile.exists()) {
System.out.println("文件不存在");
return;
}
BufferedImage image = ImageIO.read(srcfile);
// 獲得縮放的比例
double ratio = 1.0;
// 判斷如果高、寬都不大于設定值，則不處理
if (image.getHeight() > height || image.getWidth() > width) {
if (image.getHeight() > image.getWidth()) {
ratio = height / image.getHeight();
} else {
ratio = width / image.getWidth();
}
}
// 計算新的圖面寬度和高度
int newWidth = (int) (image.getWidth() * ratio);
int newHeight = (int) (image.getHeight() * ratio);
BufferedImage bfImage = new BufferedImage(newWidth, newHeight,
BufferedImage.TYPE_INT_RGB);
bfImage.getGraphics().drawImage(
image.getScaledInstance(newWidth, newHeight,
Image.SCALE_SMOOTH), 0, 0, null);
FileOutputStream os = new FileOutputStream(dist);
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(os);
encoder.encode(bfImage);
os.close();
System.out.println("創建縮略圖成功");
} catch (Exception e) {
System.out.println("創建縮略圖發生異常" + e.getMessage());
}
}
public static void main(String[] args) {
createThumbnail("E:\\test_1920x1200.jpg", "D:\\a.png", 100, 100);
createThumbnail("E:\\test_1920x1200.jpg", "D:\\b.png", 2000, 2000);
createThumbnail("E:\\test_1920x1200.jpg", "D:\\c.jpg", 800, 600);
}
}