Java 9 多分辨率图像 API

Java 9 定义多分辨率图像 API，开发者可以很容易的操作和展示不同分辨率的图像了。

以下是多分辨率图像的主要操作方法：

  • Image getResolutionVariant(double destImageWidth, double destImageHeight) − 获取特定分辨率的图像变体-表示一张已知分辨率单位为DPI的特定尺寸大小的逻辑图像，并且这张图像是最佳的变体。。

  • ListJava 9 多分辨率图像 API - 图1 getResolutionVariants() − 返回可读的分辨率的图像变体列表。

实例

  1. import java.io.IOException;
  2. import java.net.URL;
  3. import java.net.MalformedURLException;
  4. import java.util.ArrayList;
  5. import java.util.List;
  6. import java.awt.Image;
  7. import java.awt.image.MultiResolutionImage;
  8. import java.awt.image.BaseMultiResolutionImage;
  10. import javax.imageio.ImageIO;
  12. public class Tester {
  13.    public static void main(String[] args) throws IOException, MalformedURLException {
  15.       List<String> imgUrls = List.of("https://www.jishuchi.com/static/images/logo.png", "https://www.jishuchi.com/uploads/201908/15b8e7c23616a965.jpeg", "https://www.jishuchi.com/uploads/201908/15bf92daf9d2194e.png");
  17.       List<Image> images = new ArrayList<Image>();
  19.       for (String url : imgUrls) {
  20.          images.add(ImageIO.read(new URL(url)));
  21.       }
  23.       // 读取所有图片
  24.       MultiResolutionImage multiResolutionImage = 
  25.          new BaseMultiResolutionImage(images.toArray(new Image[0]));
  27.       // 获取图片的所有分辨率
  28.       List<Image> variants = multiResolutionImage.getResolutionVariants();
  30.       System.out.println("Total number of images: " + variants.size());
  32.       for (Image img : variants) {
  33.          System.out.println(img);
  34.       }
  36.       // 根据不同尺寸获取对应的图像分辨率
  37.       Image variant1 = multiResolutionImage.getResolutionVariant(156, 45);
  38.       System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 
  39.          156, 45, variant1.getWidth(null), variant1.getHeight(null));
  41.       Image variant2 = multiResolutionImage.getResolutionVariant(311, 89);
  42.       System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 311, 89, 
  43.          variant2.getWidth(null), variant2.getHeight(null));
  45.       Image variant3 = multiResolutionImage.getResolutionVariant(622, 178);
  46.       System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 622, 178, 
  47.          variant3.getWidth(null), variant3.getHeight(null));
  49.       Image variant4 = multiResolutionImage.getResolutionVariant(300, 300);
  50.       System.out.printf("\nImage for destination[%d,%d]: [%d,%d]", 300, 300, 
  51.          variant4.getWidth(null), variant4.getHeight(null));
  52.    }  
  53. }