Java判断图片格式的代码详解编程语言

import java.io.File;   
import java.io.IOException;   
import java.util.Iterator;   
import javax.imageio.ImageIO;   
import javax.imageio.ImageReader;   
import javax.imageio.stream.ImageInputStream;   
   
public class ImageDemo {   
   
    /**  
     * @param args  
     */   
    public static void main(String[] args) {   
           
        File file = new File("E:/download_test/pics/1c/1cd5v0uya36wg0rf4fu39dtym.png");   
           
        boolean result = isImage(file);   
        System.out.println("result="+result);   
           
        getExtension(file);   
    }   
       
    public static void getExtension(File file) {   
        ImageInputStream iis = null;   
        try {   
            iis = ImageIO.createImageInputStream(file);   
            Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);    
            if(iter.hasNext()){   
                System.out.println("扩展名:"+iter.next().getFormatName());   
            }   
        } catch (IOException e) {   
            e.printStackTrace();   
        }finally{   
            if(iis!=null){   
                try {   
                    iis.close();   
                } catch (IOException e) {   
                    e.printStackTrace();   
                }   
            }   
        }   
    }   
   
    public static boolean isImage(File resFile){   
        ImageInputStream iis = null;   
        try {   
            iis = ImageIO.createImageInputStream(resFile);   
            Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);    
            if (iter.hasNext()) {//文件不是图片    
                return true;   
            }    
               
        } catch (IOException e) {   
            e.printStackTrace();   
        }finally{   
            if(iis!=null){   
                try {   
                    iis.close();   
                } catch (IOException e) {   
                    e.printStackTrace();   
                }   
            }   
        }   
        return false;   
    }   
       
}