java将图片压缩到指定大小以内并保存图片(图片缩略)

刺骨的言语ヽ痛彻心扉 2024-03-27 14:10 58阅读 0赞

### 1：本地文件的压缩 ###

public static void main(String[] args) {
        
            //String path="C:\\Users\\dell\\Desktop\\文章\\6.png";
            String path = "C:\\Users\\dell\\Desktop\\微信图片_20230201212653.png";
            try {
        
    
                //图片所在路径
    
                BufferedImage templateImage = ImageIO.read(new File(path));
    
                //原始图片的长度和宽度
    
                int height = templateImage.getHeight();
    
                int width = templateImage.getWidth();
    
                //通过比例压缩
    
                float scale = 0.5f;
    
                //通过固定长度压缩
    
                int doWithHeight = 200;
    
                int dowithWidth = 200;
    
                //压缩之后的长度和宽度
    
                // int doWithHeight = (int) (scale * height);
    
                //int dowithWidth = (int) (scale * width);
    
                BufferedImage finalImage = new BufferedImage(dowithWidth, doWithHeight, BufferedImage.TYPE_INT_RGB);
    
                finalImage.getGraphics().drawImage(templateImage.getScaledInstance(dowithWidth, doWithHeight, java.awt.Image.SCALE_SMOOTH), 0, 0, null);
    
                //图片输出路径，以及图片名
    
                FileOutputStream fileOutputStream = new FileOutputStream("C:\\Users\\dell\\Desktop\\文章\\6-200.png");
    
                JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fileOutputStream);
    
                encoder.encode(finalImage);
    
                fileOutputStream.close();
    
            } catch (IOException e) {
        
    
                e.printStackTrace();
    
            }
    
    
        }

### 2：url文件的压缩 ###

### 3：图片缩略到指定大小 ###

@SneakyThrows
        public static void main(String[] args) {
        
            //String path="C:\\Users\\dell\\Desktop\\文章\\6.png";
    //        String path = "C:\\Users\\dell\\Desktop\\微信图片_20230201212653.png";
            String path = "http://192.168.11.50:8081/jeecg-boot/sys/sysMeetingManage/download/68ac9b4d-ef21-414c-8b31-18998aadf4c7.png";
            String substring = path.substring(path.lastIndexOf("/")+1);
            File file = new File("D://opt//upFiles//" + substring);
            boolean exists = file.exists();
            if (exists){
        
                Thumbnails.of(file).size(200,200).toFile("D://opt//upFiles//"+ getFileNameNoEx(substring)+"_200_200"+ getFileNameEx(substring));
            }else {
        
                System.out.println("文件不存在");
            }
    
    
        }
    
        public void saveFileFromInputStream(InputStream is, String path, String filename, int fileSize) throws IOException {
        
            String fullPathName = "";
            if (isWindows()) {
        
                fullPathName = path + "\\" + filename;
            } else {
        
                fullPathName = path + "/" + filename;
            }
            FileOutputStream fs = new FileOutputStream(fullPathName);
            byte[] buffer = null;
            if (fileSize > (1024 * 1024)) {
        
                buffer = new byte[1024 * 1024];// 按1M写入
            } else {
        
                buffer = new byte[fileSize];// 按1M写入
            }
            int byteread = 0;
            while ((byteread = is.read(buffer)) != -1) {
        
                fs.write(buffer, 0, byteread);
                fs.flush();
            }
            fs.close();
            is.close();
    
            //写入缩略图
            if( filename.toUpperCase().endsWith(".PNG") || filename.toUpperCase().contains(".JPEG") || filename.toUpperCase().contains(".JPG") )
            {
        
                String thumFilePath = "";
                if (isWindows()) {
        
                    thumFilePath = path + "\\" + getFileNameNoEx(filename)+"_200_200"+ getFileNameEx(filename);
                } else {
        
                    thumFilePath = path + "/" + getFileNameNoEx(filename)+"_200_200"+ getFileNameEx(filename);;
                }
    
                Thumbnails.of(fullPathName).size(200,200).toFile(thumFilePath);
            }
    
        }
    
        public static boolean isLinux() {
        
            return System.getProperty("os.name").toLowerCase().indexOf("linux") >= 0;
        }
    
        public static boolean isWindows() {
        
            return System.getProperty("os.name").toLowerCase().indexOf("windows") >= 0;
        }
    
        public static String getFileNameNoEx(String filename) {
        
            if ((filename != null) && (filename.length() > 0)) {
        
                int dot = filename.lastIndexOf('.');
                if ((dot >-1) && (dot < (filename.length()))) {
        
                    return filename.substring(0, dot);
                }
            }
            return filename;
        }
    
        public static String getFileNameEx(String filename) {
        
            if ((filename != null) && (filename.length() > 0)) {
        
                int dot = filename.lastIndexOf('.');
                if ((dot >-1) && (dot < (filename.length()))) {
        
                    return filename.substring(dot, filename.length());
                }
            }
            return filename;
        }

> ### 注意：踩过的坑，文件名不可以带*好，带*会报java.io.FileNotFoundException ###