用java處理圖片（壓縮成小尺寸；加文字和logo水印）

/功能：壓縮圖片變成小尺寸
  參數1：oImage：原圖；
  參數2：maxWidth：小尺寸寬度；
  參數3：maxHeight：小尺寸長度；
  參數4：newImageName：小尺寸圖片存放的路徑和新名字；
  參數5：fileType：小尺寸圖片類型（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));// 存盤
    }

/功能：圖片加文字水印
  參數1：oImage：原圖；
  參數2：newImageName：加文字水印圖片存放的路徑和新名字；
  參數3：fileType：加文字水印圖片類型（png,gif,jpg...）；
  參數4：waterText：文字水印的內容**/
  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("宋體", 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-lenfontSize/2-6,originalHeight-6);
        }else{
         g.drawString(InitServlet.WATER_TEXT, (originalWidth-(lenfontSize))/2, (originalHeight-fontSize)/2);
        }
        g.dispose();
 ImageIO.write(newImage, fileType, new FileOutputStream(newImageName));// 存盤
 return true;
    }

/***功能：圖片加logo圖片水印***

參數1：oImage：原圖；
  參數2：newImageName：加logo圖片水印存放的路徑和新名字；
  參數3：fileType：加logo圖片水印圖片類型（png,gif,jpg...）；
  參數4：logoPath：logo水印圖片的存放路徑**/ 
  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));// 存盤
 return true;
    }</pre>