用java处理图片（压缩成小尺寸；加文字和logo水印）

  /***功能：压缩图片变成小尺寸***
  *参数1：oImage：原图；*
  *参数2：maxWidth：小尺寸宽度；*
  *参数3：maxHeight：小尺寸长度；*
  *参数4：newImageName：小尺寸图片存放的路径和新名字；*
  *参数5：fileType：小尺寸图片类型（png,gif,jpg...）***/
  private void compressImage(File oImage, int maxWidth, int maxHeight, String newImageName, String fileType) {
        BufferedImage srcImage = ImageIO.read(oImage);;
        int srcWidth = srcImage.getWidth(null);
        int srcHeight = srcImage.getHeight(null);
        if(srcWidth <= maxWidth && srcHeight <= maxHeight){
            saveImage(srcImage);
            return;
        }
        Image scaledImage = srcImage.getScaledInstance(srcWidth, srcHeight, Image.SCALE_SMOOTH);
        double ratio = Math.min((double) maxWidth / srcWidth, (double) maxHeight / srcHeight);
        AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);
        scaledImage = op.filter(srcImage, null);
        saveImage((BufferedImage)scaledImage, fileType, new FileOutputStream(newImageName));// 存盘
    }

    private void saveImage(BufferedImage bi, String savePath, String fileType) throws IOException {
        FileOutputStream out = new FileOutputStream(savePath);
        ImageIO.write(bi, fileType, out);// 存盘
        out.flush();
        out.close();
    }

  /***功能：图片加文字水印***
  *参数1：oImage：原图；*
  *参数2：newImageName：加文字水印图片存放的路径和新名字；*
  *参数3：fileType：加文字水印图片类型（png,gif,jpg...）；
  *参数4：waterText：文字水印的内容****/
  private boolean pressText(File oImage, String newImageName, String fileType, String waterText) throws IOException{
        BufferedImage originalImage = ImageIO.read(oImage);
        int originalWidth = originalImage.getWidth(null);
        int originalHeight = originalImage.getHeight(null);
        if (originalWidth < 50 || originalHeight < 50){
            return false;
        }
        if(waterText==null || waterText.trim().equals("")){
         return false;
        }
        BufferedImage newImage = new BufferedImage(originalWidth, originalHeight, BufferedImage.TYPE_INT_RGB);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(originalImage, 0, 0, originalWidth, originalHeight, null);
        g.setColor(Color.RED);
        int fontSize = 13;
        g.setFont(new Font("宋体", Font.PLAIN, fontSize));
        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.5f));
        int len = InitServlet.WATER_TEXT.length();
        if(InitServlet.IS_WATER_CENTER==0){
         g.drawString(InitServlet.WATER_TEXT, originalWidth-len*fontSize/2-6,originalHeight-6);
        }else{
         g.drawString(InitServlet.WATER_TEXT, (originalWidth-(len*fontSize))/2, (originalHeight-fontSize)/2);
        }
        g.dispose();
 ImageIO.write(newImage, fileType, new FileOutputStream(newImageName));// 存盘
 return true;
    }

    /***功能：图片加logo图片水印***
  *参数1：oImage：原图；*
  *参数2：newImageName：加logo图片水印存放的路径和新名字；*
  *参数3：fileType：加logo图片水印图片类型（png,gif,jpg...）；
  *参数4：logoPath：logo水印图片的存放路径****/ 
  private boolean pressImage(File oImage, String newImageName, String fileType, String logoPath) throws IOException{
        File waterMarkImage = new File(logoPath);
        if (!waterMarkImage.exists()) {
         return false;
        }
        BufferedImage originalImage = ImageIO.read(oImage);
        BufferedImage watermarkImage = ImageIO.read(waterMarkImage);
        int originalWidth = originalImage.getWidth(null);
        int originalHeight = originalImage.getHeight(null);
        int watermarkWidth = watermarkImage.getWidth(null);
        int watermarkHeight = watermarkImage.getHeight(null);
        if (originalWidth <= watermarkWidth || originalHeight <= watermarkHeight || originalWidth < 50 || originalHeight < 50) {
         return false;
        }
        BufferedImage newImage = new BufferedImage(originalWidth, originalHeight, BufferedImage.TYPE_INT_RGB);
        Graphics2D g = newImage.createGraphics();
        g.drawImage(originalImage, 0, 0, originalWidth, originalHeight, null);
        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.5f));
        if(InitServlet.IS_WATER_CENTER==0){
         g.drawImage(watermarkImage, originalWidth-watermarkWidth-10, originalHeight-watermarkHeight-10, watermarkWidth, watermarkHeight, null);
        }else{
         g.drawImage(watermarkImage, (originalWidth-watermarkWidth)/2, (originalHeight-watermarkHeight)/2, watermarkWidth, watermarkHeight, null);
        }
        g.dispose();
 ImageIO.write(newImage, fileType, new FileOutputStream(newImageName));// 存盘
 return true;
    }