Java 获取图片的大小、宽、高

参考：https://www.cnblogs.com/hongten/archive/2012/11/26/hongten_java_ImageReader_BufferedImage.html

 1 import java.awt.image.BufferedImage;
 2 import java.io.File;
 3 import java.io.FileInputStream;
 4 import java.io.FileNotFoundException;
 5 import java.io.IOException;
 6 
 7 import javax.imageio.ImageIO;
 8 
 9 public class Picture {
10     public static void main(String[] args) throws FileNotFoundException, IOException {
11         File picture = new File("E:/PrintScreen/StarSky.jpg");
12         BufferedImage sourceImg = ImageIO.read(new FileInputStream(picture));
13         
14         System.out.println(String.format("Size: %.1f KB", picture.length()/1024.0));
15         System.out.println("Width: " + sourceImg.getWidth());
16         System.out.println("Height: " + sourceImg.getHeight());
17     }
18 }

这个没看懂！

 1 import java.io.File;
 2 import java.io.IOException;
 3 import java.util.Iterator;
 4 
 5 import javax.imageio.ImageIO;
 6 import javax.imageio.ImageReader;
 7 import javax.imageio.stream.ImageInputStream;
 8 
 9 public class Picture {
10     public static void main(String[] args) {
11         String srcPath = "E:/PrintScreen/1.jpg";
12         
13         File file = new File(srcPath);
14         try {
15             Iterator<ImageReader> readers = ImageIO.getImageReadersByFormatName("jpg");
16             ImageReader reader = (ImageReader) readers.next();
17             ImageInputStream iis = ImageIO.createImageInputStream(file);
18             reader.setInput(iis, true);
19             System.out.println(" " + reader.getWidth(0));
20             System.out.println("height: " + reader.getHeight(0));
21         } catch (IOException e) {
22             e.printStackTrace();
23         }
24     }
25 }

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注意：图片是预先存放在Java Project下的Package中

 1 import java.awt.Image;
 2 import java.awt.image.BufferedImage;
 3 import java.io.IOException;
 4 import java.net.URL;
 5 
 6 import javax.imageio.ImageIO;
 7 
 8 public class GetImageSize {
 9     public static void main(String[] args) throws IOException {
10         BufferedImage bi = null;
11         
12         try {
13             URL u = GetImageSize.class.getClassLoader().getResource("images/background.png");
14             bi = ImageIO.read(u);
15         } catch (IOException e) {
16             e.printStackTrace();
17         }
18         Image img = bi;
19         
20         System.out.println(img.getWidth(null));
21         System.out.println(img.getHeight(null));
22     }
23 }