Java判斷圖片格式的代碼

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("擴展名:"+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()) {//文件不是圖片   
            return true;  
        }   

    } catch (IOException e) {  
        e.printStackTrace();  
    }finally{  
        if(iis!=null){  
            try {  
                iis.close();  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
    }  
    return false;  
}  


}  </pre>