Java实现的上传并压缩图片功能

本文实例讲述了Java实现的上传并压缩图片功能。分享给大家供大家参考，具体如下：

先看效果：

原图：1.33M

处理后：27.4kb

关键代码：

package codeGenerate.util;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ImageZipUtil {
  public static void main(String[] args) {
    zipWidthHeightImageFile(new File("C:\spider\3.png"),new File("C:\spider\3-1.jpg"),425,638,0.7f);
    //zipImageFile(new File("C:\spider\2.JPG"),new File("C:\spider\2-2.JPG"),425,638,0.7f);
    //zipImageFile(new File("C:\spider\3.jpg"),new File("C:\spider\3-3.jpg"),425,638,0.7f);
    System.out.println("ok");
  }
  
  public static String zipImageFile(File oldFile,File newFile, int width, int height,float quality) {
    if (oldFile == null) {
      return null;
    }
    try {
      
      Image srcFile = ImageIO.read(oldFile);
      int w = srcFile.getWidth(null);
      int h = srcFile.getHeight(null);
      double bili;
      if(width>0){
 bili=width/(double)w;
 height = (int) (h*bili);
      }else{
 if(height>0){
   bili=height/(double)h;
   width = (int) (w*bili);
 }
      }
      String srcImgPath = newFile.getAbsoluteFile().toString();
      System.out.println(srcImgPath);
      String subfix = "jpg";
      subfix = srcImgPath.substring(srcImgPath.lastIndexOf(".")+1,srcImgPath.length());
      BufferedImage buffImg = null;
      if(subfix.equals("png")){
 buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
      }else{
 buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
      }
      Graphics2D graphics = buffImg.createGraphics();
      graphics.setBackground(new Color(255,255,255));
      graphics.setColor(new Color(255,255,255));
      graphics.fillRect(0, 0, width, height);
      graphics.drawImage(srcFile.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0, null);
      ImageIO.write(buffImg, subfix, new File(srcImgPath));
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
    return newFile.getAbsolutePath();
  }
  
  public static String zipWidthHeightImageFile(File oldFile,File newFile, int width, int height,float quality) {
    if (oldFile == null) {
      return null;
    }
    String newImage = null;
    try {
      
      Image srcFile = ImageIO.read(oldFile);
      String srcImgPath = newFile.getAbsoluteFile().toString();
      System.out.println(srcImgPath);
      String subfix = "jpg";
      subfix = srcImgPath.substring(srcImgPath.lastIndexOf(".")+1,srcImgPath.length());
      BufferedImage buffImg = null;
      if(subfix.equals("png")){
 buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
      }else{
 buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
      }
      Graphics2D graphics = buffImg.createGraphics();
      graphics.setBackground(new Color(255,255,255));
      graphics.setColor(new Color(255,255,255));
      graphics.fillRect(0, 0, width, height);
      graphics.drawImage(srcFile.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0, null);
      ImageIO.write(buffImg, subfix, new File(srcImgPath));
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
    return newImage;
  }
}

说明：

1、根据需求大家可以自行设置质量参数quality，到底设置成多少，可以先看下效果在取值；

2、网上通用的方法用的是jdk自带jar包中方法，我这里衍生了一下：用Graphics2D，能够同时处理jpg和png格式；

3、new Color(255,255,255)是白色，等同于WHITE，但是用WHITE 的话，Linux下某些图片会有其它色值；

4、main中的宽425和高638可以根据自己的需求自行设置，但是对于长和宽一样的，按照400（小值的值425）*400来处理；

更多java相关内容感兴趣的读者可查看本站专题：《Java图片操作技巧汇总》、《java日期与时间操作技巧汇总》、《Java操作DOM节点技巧总结》、《Java文件与目录操作技巧汇总》及《Java数据结构与算法教程》。

希望本文所述对大家java程序设计有所帮助。