java实现图片格式转换为JPG

package org.xcj;


import java.io.File;  
import java.io.IOException;  
import java.util.ArrayList;
import java.util.Iterator;  
import javax.imageio.ImageIO;  
import javax.imageio.ImageReader;  
import javax.imageio.stream.ImageInputStream;  
import java.awt.image.ImageProducer;
import com.sun.jimi.core.Jimi;
import com.sun.jimi.core.JimiException;
import com.sun.jimi.core.JimiWriter;
import com.sun.jimi.core.options.JPGOptions;

public class Test{ 

/** * 测试函数 * @param args * @throws IOException */
public static void main(String[] args) throws IOException{

//图片文件夹路径
String pathName = "F:/test";

//存放文件名的集合
ArrayList<String>  fileNameList = getFileName(pathName);

//遍历文件名集合
Iterator<String> iter = fileNameList.iterator();

while(iter.hasNext()){

String fileName = iter.next();

File file = new File(pathName+"/"+fileName); 

//判断是否为图片
         boolean result = isImage(file);

         if(result){

         //获取图片的格式
         String format = getExtension(file);

         System.out.println("图片格式为:"+format);

         //将图片格式转换为JPEG
         if(format != "JPEG"){

         //需要修改的文件路径
         String input = pathName+"/"+fileName;

         //将文件路径改为.jpg
         String[] stringSplit = fileName.split("\\.");
         String output = pathName+"/"+stringSplit[0]+".jpg";

         //转换图片格式
         forJpg(input,output);

         }
         }
        }
}

/** * 获取文件夹内所有的文件名 * @param pathName */
public static ArrayList<String> getFileName(String pathName){

//存放遍历出来的文件名字
        ArrayList<String>  nameList = new ArrayList<String> ();

File dirFile = new File(pathName);

        //获取此目录下的所有文件名与目录名 
        String[] fileList = dirFile.list();

        for(int i = 0; i < fileList.length; i++){

         //遍历文件目录 
            String string = fileList[i];  

            File file = new File(dirFile.getPath(),string);  

            String name = file.getName();

            nameList.add(name);
        }

        return nameList;
}

/** * 获取图片格式函数 * @param file * @return */
public static String getExtension(File file){
//图片格式
     String format = ""; 

        ImageInputStream iis = null;  

        try{  

         iis = ImageIO.createImageInputStream(file);  

            Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);   

            if(iter.hasNext()){  

                format = iter.next().getFormatName();
            }

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

        return format; 

}

/** * 判断是否为图片函数 * @param file * @return */
public static boolean isImage(File resFile){

ImageInputStream iis = null;  

try{ 

iis = ImageIO.createImageInputStream(resFile); 

Iterator<ImageReader> iter = ImageIO.getImageReaders(iis);   

//文件是不是图片
if(iter.hasNext()){   

return true;  

}   

        }catch(IOException e) {  

         e.printStackTrace();  

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

/** * 将图片格式转换为JPG格式 * @param input * @param output * @throws IOException */
public static void forJpg(String input,String output) throws IOException {

try{
JPGOptions options = new JPGOptions();
            options.setQuality(72);

            ImageProducer image = Jimi.getImageProducer(input);
            JimiWriter writer = Jimi.createJimiWriter(output);

            writer.setSource(image);
            writer.setOptions(options);
            writer.putImage(output);

            // 转换后删除原文件
            File f = new File(input);
            f.delete();
}catch(JimiException e) {
System.err.println("Error: " + e);
         e.printStackTrace();
}

}
}