java实现图片压缩

java 实现图片压缩

package com.rongyi.common.utils;import java.awt.Color;import java.awt.Graphics2D;import java.awt.Image;import java.awt.image.BufferedImage;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.net.URL;import javax.imageio.ImageIO;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGEncodeParam;import com.sun.image.codec.jpeg.JPEGImageEncoder;public class ImageUtils {    public static void generateImage(String outImgPath,BufferedImage  src,int new_w,int new_h) throws IOException    {        float per=0.9f;        //原图片地址        //File file = new File(inImgPath);        //BufferedImage  src = ImageIO.read(inStream);        //System.out.println(inStream.toString());        //得到原始宽度        int old_w = src.getWidth();        //得到原始高度        int old_h = src.getHeight();        //根据原始大小生成一个空白画布        BufferedImage tempImage = new BufferedImage(old_w,old_h,BufferedImage.TYPE_INT_BGR);        // 在新的画布上生成原图的缩略图        Graphics2D g = tempImage.createGraphics();        g.setColor(Color.white);        g.fillRect(0, 0, old_w, old_h);        g.drawImage(src, 0, 0, old_w, old_h, Color.white, null);        g.dispose();         BufferedImage newImg = new BufferedImage(new_w, new_h,                      BufferedImage.TYPE_INT_RGB);              newImg.getGraphics().drawImage(                      tempImage.getScaledInstance(new_w, new_h, Image.SCALE_SMOOTH), 0,                      0, null);              // 调用方法输出图片文件              File outfile =new File(outImgPath);            if (!outfile.getParentFile().exists())             {                  outfile.getParentFile().mkdirs();              }            FileOutputStream newimage = new FileOutputStream(outImgPath);              JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(newimage);             JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(newImg);              jep.setQuality(per, false);            encoder.encode(newImg,jep);              newimage.close();    }    public static void compressionOfProportion(String outImgPath,int new_w,int new_h,InputStream inStream) throws IOException{        BufferedImage bi = ImageIO.read(inStream);        double width = bi.getWidth();        double heigth = bi.getHeight();        if(width > new_w || heigth > new_h){            double wscale = width/new_w;            double hscale = heigth/new_h;            if(wscale > hscale){                new_h = (int)Math.round(heigth/wscale);            }else{                new_w = (int)Math.round(width/hscale);            }        }else{            new_h = (int)heigth;            new_w = (int)width;        }        ImageUtils.generateImage(outImgPath, bi, new_w, new_h);    }     // 生成图片函数      public static void makeImg(String imgUrl,String fileURL) {          try {              // 创建流              BufferedInputStream in = new BufferedInputStream(new URL(imgUrl).openStream());              // 生成图片名              int index = imgUrl.lastIndexOf("/");              String sName = imgUrl.substring(index+1, imgUrl.length());              System.out.println(sName);              // 存放地址              File img = new File(fileURL+sName);              // 生成图片              BufferedOutputStream out = new BufferedOutputStream(                      new FileOutputStream(img));              byte[] buf = new byte[2048];              int length = in.read(buf);              while (length != -1) {                  out.write(buf, 0, length);                  length = in.read(buf);              }              in.close();              out.close();          } catch (Exception e) {              e.printStackTrace();          }      }     /*public static void main(String[] args) {//      double d = 800.0/51;//      System.out.println(d);        try {            //File addrFile = new File("D:/1.jpg");            //compressionOfProportion("D:/2.jpg","D:/1.jpg",600, 600,addrFile);            //compressionOfProportion("F:/img/2.jpg","F:/img/org.jpg",200, 200,addrFile);            //compressionOfProportion("F:/img/3.jpg","F:/img/org.jpg",300, 300,addrFile);            //compressionOfProportion("F:/img/4.jpg","F:/img/org.jpg",400, 400,addrFile);            //compressionOfProportion("F:/img/5.jpg","F:/img/org.jpg",600, 600,addrFile);        } catch (IOException e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }*/}