java实现图片裁剪缩放工具类

import java.awt.Image; 
import java.awt.Rectangle; 
import java.awt.geom.AffineTransform; 
import java.awt.image.AffineTransformOp; 
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.util.Iterator; 
 
import javax.imageio.ImageIO; 
import javax.imageio.ImageReadParam; 
import javax.imageio.ImageReader; 
import javax.imageio.stream.ImageInputStream; 
 
public class ImageHelper { 
    /*
     * 根据尺寸图片居中裁剪
     */ 
     public static void cutCenterImage(String src,String dest,int w,int h) throws IOException{  
         Iterator iterator = ImageIO.getImageReadersByFormatName("jpg");  
         ImageReader reader = (ImageReader)iterator.next();  
         InputStream in=new FileInputStream(src); 
         ImageInputStream iis = ImageIO.createImageInputStream(in);  
         reader.setInput(iis, true);  
         ImageReadParam param = reader.getDefaultReadParam();  
         int imageIndex = 0;  
         Rectangle rect = new Rectangle((reader.getWidth(imageIndex)-w)/2, (reader.getHeight(imageIndex)-h)/2, w, h);   
         param.setSourceRegion(rect);  
         BufferedImage bi = reader.read(0,param);    
         ImageIO.write(bi, "jpg", new File(dest));            
   
     } 
    /*
     * 图片裁剪二分之一
     */ 
     public static void cutHalfImage(String src,String dest) throws IOException{  
         Iterator iterator = ImageIO.getImageReadersByFormatName("jpg");  
         ImageReader reader = (ImageReader)iterator.next();  
         InputStream in=new FileInputStream(src); 
         ImageInputStream iis = ImageIO.createImageInputStream(in);  
         reader.setInput(iis, true);  
         ImageReadParam param = reader.getDefaultReadParam();  
         int imageIndex = 0;  
         int width = reader.getWidth(imageIndex)/2;  
         int height = reader.getHeight(imageIndex)/2;  
         Rectangle rect = new Rectangle(width/2, height/2, width, height);  
         param.setSourceRegion(rect);  
         BufferedImage bi = reader.read(0,param);    
         ImageIO.write(bi, "jpg", new File(dest));    
     } 
    /*
     * 图片裁剪通用接口
     */ 
 
    public static void cutImage(String src,String dest,int x,int y,int w,int h) throws IOException{  
           Iterator iterator = ImageIO.getImageReadersByFormatName("jpg");  
           ImageReader reader = (ImageReader)iterator.next();  
           InputStream in=new FileInputStream(src); 
           ImageInputStream iis = ImageIO.createImageInputStream(in);  
           reader.setInput(iis, true);  
           ImageReadParam param = reader.getDefaultReadParam();  
           Rectangle rect = new Rectangle(x, y, w,h);   
           param.setSourceRegion(rect);  
           BufferedImage bi = reader.read(0,param);    
           ImageIO.write(bi, "jpg", new File(dest));            
 
    }  
    /*
     * 图片缩放
     */ 
    public static void zoomImage(String src,String dest,int w,int h) throws Exception { 
        double wr=0,hr=0; 
        File srcFile = new File(src); 
        File destFile = new File(dest); 
        BufferedImage bufImg = ImageIO.read(srcFile); 
        Image Itemp = bufImg.getScaledInstance(w, h, bufImg.SCALE_SMOOTH); 
        wr=w*1.0/bufImg.getWidth(); 
        hr=h*1.0 / bufImg.getHeight(); 
        AffineTransformOp ato = new AffineTransformOp(AffineTransform.getScaleInstance(wr, hr), null); 
        Itemp = ato.filter(bufImg, null); 
        try { 
            ImageIO.write((BufferedImage) Itemp,dest.substring(dest.lastIndexOf(".")+1), destFile); 
        } catch (Exception ex) { 
            ex.printStackTrace(); 
        } 
         
    } 
}