java改变图片文件尺寸

方式一：缩放图片（缺点：如果需要固定尺寸图片，那么会使得原图变形）

1.单个图片尺寸处理：

package test.common;

import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;


public class ImgTest {
    private Image img;
    private final static int WIDTH = 147;
    private final static int HEIGHT = 136;

    /**
     * 改变图片的大小到宽为size，然后高随着宽等比例变化
     * @param is 上传的图片的输入流
     * @param os 改变了图片的大小后，把图片的流输出到目标OutputStream
     * @param size 新图片的宽
     * @param format 新图片的格式
     * @throws IOException
     */
    public static OutputStream resizeImage(InputStream is, OutputStream os, int size, String format) throws IOException {
        BufferedImage prevImage = ImageIO.read(is);
        double width = prevImage.getWidth();
        double height = prevImage.getHeight();
        double percent = size/width;
        int newWidth = (int)(width * percent);
        int newHeight = (int)(height * percent);
        BufferedImage image = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_BGR);
        Graphics graphics = image.createGraphics();
        graphics.drawImage(prevImage, 0, 0, newWidth, newHeight, null);
        ImageIO.write(image, format, os);
        os.flush();
        is.close();
        os.close();
        ByteArrayOutputStream b = (ByteArrayOutputStream) os;
        return os;
    }
    
    public static void main(String[] args) {
        try {
            InputStream is = new FileInputStream(new File("download/qrcode_test.jpg"));
            OutputStream os = new FileOutputStream(new File("download/qrcode_test_1.jpg"));
            resizeImage(is, os, 10, "png");
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

2.批量图片尺寸处理：

package com.test;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.LinkedHashMap;

import javax.imageio.ImageIO;
public class ImgChange {
        private Image img;
        private final static int WIDTH = 147;
        private final static int HEIGHT = 136;

        /**
         * 改变图片的大小到宽为size，然后高随着宽等比例变化
         * @param is 上传的图片的输入流
         * @param os 改变了图片的大小后，把图片的流输出到目标OutputStream
         * @param size 新图片的宽
         * @param format 新图片的格式
         * @throws IOException
         */
        public static OutputStream resizeImage(InputStream is, OutputStream os, int size, String format) throws IOException {
            BufferedImage prevImage = ImageIO.read(is);
            double width = prevImage.getWidth();
            double height = prevImage.getHeight();
            int newWidth = 600;
            int newHeight = 800;
            BufferedImage image = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_BGR);
            Graphics graphics = image.createGraphics();
            graphics.drawImage(prevImage, 0, 0, newWidth, newHeight, null);
            ImageIO.write(image, format, os);
            os.flush();
            is.close();
            os.close();
            //ByteArrayOutputStream b = (ByteArrayOutputStream) os;
            return os;
        }
        
        /**
         * 读取某个目录下所有文件、文件夹
         * @param path
         * @return LinkedHashMap<String,String>
         */
        public static LinkedHashMap<String,String> getFiles(String path) {
            LinkedHashMap<String,String> files = new LinkedHashMap<String,String>();
            File file = new File(path);
            File[] tempList = file.listFiles();
     
            for (int i = 0; i < tempList.length; i++) {
                if (!tempList[i].isDirectory()) {
                    files.put(tempList[i].getName(),tempList[i].getPath());
                }
            }
            return files;
        }
        
        public static void main(String[] args) {
            try {
                LinkedHashMap<String,String> files = getFiles("D:/img");
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
                Date beginDate = new Date(); 
                System.out.println("开始："+sdf.format(beginDate));
                for (String fileName : files.keySet()) {
                    InputStream is = new FileInputStream(new File(files.get(fileName)));
                    OutputStream os = new FileOutputStream(new File("D:/imgCopy/"+fileName));
                    resizeImage(is, os, 10, "jpg");
                }
                Date endDate = new Date(); 
                System.out.println("结束："+sdf.format(endDate));
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
}

 方式二：裁剪图片（缺点：可能会使得图片展示不完全，只能取到图片中间部分的内容）

package com.test;

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.imageio.ImageIO;

public class ImgCrop {

    /**
     * 改变图片的大小到宽为size，然后高随着宽等比例变化
     * @param is 上传的图片的输入流
     * @param os 改变了图片的大小后，把图片的流输出到目标OutputStream
     * @param size 新图片的宽
     * @param format 新图片的格式
     * @throws IOException
     */
    public static OutputStream resizeImage(BufferedImage bufferedimage,int widht,int height,OutputStream os, String format) throws IOException {
        BufferedImage image = new BufferedImage(widht, height, BufferedImage.TYPE_INT_BGR);
        Graphics graphics = image.createGraphics();
        graphics.drawImage(bufferedimage, 0, 0, widht, height, null);
        ImageIO.write(image, format, os);
        os.flush();
        os.close();
        return os;
    }
    
    
/**
 * * 裁剪图片方法 * 
 * @param bufferedImage 图像源 * 
 * @param startX 裁剪开始x坐标 * 
 * @param startY 裁剪开始y坐标 * 
 * @param endX 裁剪结束x坐标 * 
 * @param endY 裁剪结束y坐标 * 
 * @return
 */
public static BufferedImage cropImage(BufferedImage Image, int startX, int startY, int endX, int endY) {
    int width = Image.getWidth();
    int height = Image.getHeight();
    if (startX == -1) {
        startX = 0;
    }
    if (startY == -1) {
        startY = 0;
    }
    if (endX == -1) {
        endX = width - 1;
    }
    if (endY == -1) {
        endY = height - 1;
    }
    BufferedImage result = new BufferedImage(endX - startX, endY - startY, 4);
    for (int x = startX; x < endX; ++x) {
        for (int y = startY; y < endY; ++y) {
            int rgb = Image.getRGB(x, y);
            result.setRGB(x - startX, y - startY, rgb);
        }
    }
    return result;
}

    
    public static void main(String[] args) throws IOException {
        //原始图片路径
        String imagePath = "D:/image";
        File imageFile = new File(imagePath);
        File[] imageFiles = imageFile.listFiles();
        for (File fimage : imageFiles) {
            BufferedImage bufferedimage=ImageIO.read(fimage); 
            int width = bufferedimage.getWidth(); 
            int height = bufferedimage.getHeight();
                    
            OutputStream os = new FileOutputStream(new File("D:/img/"+fimage.getName()));
            resizeImage(bufferedimage,width,height,os,"jpg");
            os.flush();
            os.close();
        }
    
        //过程图片路径
        String path = "D:/img";
        dealImg(path);
        
        String cachePath = "D:/imgCache";
        File file = new File(cachePath);
        File[] files = file.listFiles();
        while(files.length>0) {
            dealImg(cachePath);
            file = new File(path);
            files = file.listFiles();
        }
    }
    
    /**
     * 处理图片
     * @param path 文件夹路径
     */
    private static void dealImg(String path) {
        try {
            File file = new File(path);
            File[] files = file.listFiles();
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
            Date beginDate = new Date(); 
            System.out.println(path+"begin："+sdf.format(beginDate));
            for (File f : files) {
                BufferedImage bufferedimage=ImageIO.read(f); 
                Double width = (double) bufferedimage.getWidth(); 
                Double height = (double) bufferedimage.getHeight();
                if (width<900||height<1200) {
                    while (width<900||height<1200) {
                        width=width*1.1;
                        height=height*1.1;
                    }
                    OutputStream os = new FileOutputStream(new File("D:/imgCache/"+f.getName()));
                    resizeImage(bufferedimage,width.intValue(),height.intValue(),os,"jpg");
                    f.delete();
                    os.flush();
                    os.close();
                       continue;
                }
                //目标将图片裁剪成 宽900，高1200 
                if (width > 900) { 
                    /*开始x坐标 开始y坐标 结束x坐标 结束y坐标*/ 
                    bufferedimage=cropImage(bufferedimage,(int) ((width - 900) / 2),0,(int) (width - (width-900) / 2),height.intValue()); 
                    if (height > 1200) { 
                        bufferedimage=cropImage(bufferedimage,0,(int) ((height - 1200) / 2),900,(int) (height - (height - 1200) / 2) ); 
                    } 
                }else{ 
                    if (height > 1200) { 
                        bufferedimage=cropImage(bufferedimage,0,(int) ((height - 1200) / 2),width.intValue(),(int) (height - (height - 1200) / 2) ); 
                    } 
                } 
                OutputStream os = new FileOutputStream(new File("D:/imgCopy/"+f.getName()));
                ImageIO.write(bufferedimage, "jpg", os); //输出裁剪图片
                f.delete();
                os.flush();
                os.close();
            }
            Date endDate = new Date(); 
            System.out.println(path+"end："+sdf.format(endDate));
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

 裁剪图片优化版：

package com.jeecg.util;

import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.imageio.ImageIO;

public class ImgCrop {

    /**
     * 改变图片的大小到宽为size，然后高随着宽等比例变化
     * @param is 上传的图片的输入流
     * @param os 改变了图片的大小后，把图片的流输出到目标OutputStream
     * @param size 新图片的宽
     * @param format 新图片的格式
     * @throws IOException
     */
    public static OutputStream resizeImage(BufferedImage bufferedimage,int widht,int height,OutputStream os, String format) throws IOException {
        BufferedImage image = new BufferedImage(widht, height, BufferedImage.TYPE_INT_BGR);
        Graphics graphics = image.createGraphics();
        graphics.drawImage(bufferedimage, 0, 0, widht, height, null);
        ImageIO.write(image, format, os);
        os.flush();
        os.close();
        return os;
    }
    
    
/**
 * * 裁剪图片方法 * 
 * @param bufferedImage 图像源 * 
 * @param startX 裁剪开始x坐标 * 
 * @param startY 裁剪开始y坐标 * 
 * @param endX 裁剪结束x坐标 * 
 * @param endY 裁剪结束y坐标 * 
 * @return
 */
public static BufferedImage cropImage(BufferedImage Image, int startX, int startY, int endX, int endY) {
    int width = Image.getWidth();
    int height = Image.getHeight();
    if (startX == -1) {
        startX = 0;
    }
    if (startY == -1) {
        startY = 0;
    }
    if (endX == -1) {
        endX = width - 1;
    }
    if (endY == -1) {
        endY = height - 1;
    }
    BufferedImage result = new BufferedImage(endX - startX, endY - startY, 4);
    for (int x = startX; x < endX; ++x) {
        for (int y = startY; y < endY; ++y) {
            int rgb = Image.getRGB(x, y);
            result.setRGB(x - startX, y - startY, rgb);
        }
    }
    return result;
}

    
    public static void main(String[] args) throws IOException {
        totalImg(300,400);
    }

    /**
     *    所有图片调用总方法
     */
    public static void totalImg(Integer wid,Integer hei) throws IOException, FileNotFoundException {
        File file1 = new File("D:/image/");
        if (!file1.exists()) {
            file1.mkdirs();
        }
        File file2 = new File("D:/img/");
        if (!file2.exists()) {
            file2.mkdirs();
        }
        File file3 = new File("D:/imgCache/");
        if (!file3.exists()) {
            file3.mkdirs();
        }
        File file4 = new File("D:/imgCopy/");
        if (!file4.exists()) {
            file4.mkdirs();
        }
        //原始图片路径
        String imagePath = "D:/image";
        File imageFile = new File(imagePath);
        File[] imageFiles = imageFile.listFiles();
        for (File fimage : imageFiles) {
            BufferedImage bufferedimage=ImageIO.read(fimage); 
            int width = bufferedimage.getWidth(); 
            int height = bufferedimage.getHeight();
                    
            OutputStream os = new FileOutputStream(new File("D:/img/"+fimage.getName()));
            resizeImage(bufferedimage,width,height,os,"jpg");
            os.flush();
            os.close();
        }
    
        //过程图片路径
        String path = "D:/img";
        dealImg(path,wid,hei,1);
        
        String cachePath = "D:/imgCache";
        File file = new File(cachePath);
        File[] files = file.listFiles();
        while(files.length>0) {
            dealImg(cachePath,wid,hei,2);
            file = new File(path);
            files = file.listFiles();
        }
    }
    
    /**
     * 处理图片
     * @param path 文件夹路径
     */
    private static void dealImg(String path,Integer wid,Integer hei,Integer type) {
        try {
            File file = new File(path);
            File[] files = file.listFiles();
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
            Date beginDate = new Date(); 
            System.out.println(path+"begin："+sdf.format(beginDate));
            for (File f : files) {
                BufferedImage bufferedimage=ImageIO.read(f); 
                Double width = (double) bufferedimage.getWidth(); 
                Double height = (double) bufferedimage.getHeight();
                
                Double w = 0.00;
                Double h = 0.00;
                if (type==1) {
                    if (width<wid||height<hei) {
                        while (width<wid||height<hei) {
                            width=width*1.1;
                            height=height*1.1;
                        }
                        OutputStream os = new FileOutputStream(new File("D:/imgCache/"+f.getName()));
                        resizeImage(bufferedimage,width.intValue(),height.intValue(),os,"jpg");
                        f.delete();
                        os.flush();
                        os.close();
                           continue;
                    }else if (width>wid&&height>hei) {
                        while (width>wid&&height>hei) {
                            width=width*0.9;
                            height=height*0.9;
                            
                            if (width<wid||height<hei) {
                                if (width<=height) {
                                    w = wid.doubleValue();
                                    h = ((wid-width)/wid)*height+height;
                                }else{
                                    h = hei.doubleValue();
                                    w = ((hei-height)/hei)*width+width;
                                }                                
                            }else{
                                w = width;
                                h = height;
                            }
                        }
                        width = w;
                        height = h;
                        OutputStream os = new FileOutputStream(new File("D:/imgCache/"+f.getName()));
                        resizeImage(bufferedimage,width.intValue(),height.intValue(),os,"jpg");
                        f.delete();
                        os.flush();
                        os.close();
                           continue;
                    }
                }
                
                //目标将图片裁剪成 宽900，高1200 
                if (width > wid) { 
                    /*开始x坐标 开始y坐标 结束x坐标 结束y坐标*/ 
                    bufferedimage=cropImage(bufferedimage,(int) ((width - wid) / 2),0,(int) (width - (width-wid) / 2),height.intValue()); 
                    if (height > hei) { 
                        bufferedimage=cropImage(bufferedimage,0,(int) ((height - hei) / 2),wid,(int) (height - (height - hei) / 2) ); 
                    } 
                }else{ 
                    if (height > hei) { 
                        bufferedimage=cropImage(bufferedimage,0,(int) ((height - hei) / 2),width.intValue(),(int) (height - (height - hei) / 2) ); 
                    } 
                } 
                OutputStream os = new FileOutputStream(new File("D:/imgCopy/"+f.getName()));
                ImageIO.write(bufferedimage, "jpg", os); //输出裁剪图片
                f.delete();
                os.flush();
                os.close();
            }
            Date endDate = new Date(); 
            System.out.println(path+"end："+sdf.format(endDate));
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}