Image

   InputStream in =null;
			try {
				in = new FileInputStream("D:\\My Documents\\My Pictures\\logo.jpg");
			} catch (FileNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}//
	        BufferedImage bi =null;
			try {
				bi = ImageIO.read(in);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} 
	              
	        Graphics g =  bi.createGraphics();
	        g.setColor(Color.blue);  
	        g.drawString("我爱你", 10, 100);
	       g.dispose();
	        
	        File file = new File("C:\\1.JPG");
	        try {
				ImageIO.write(bi, "JPEG", file);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}//JPEG或JPG
	        try {
				in.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} 

 
/**
	 * 文字水印
	 * @param pressText 水印文字
	 * @param targetImg 目标图片
	 * @param fontName 字体名称
	 * @param fontStyle 字体样式
	 * @param color 字体颜色
	 * @param fontSize 字体大小
	 * @param x 修正值
	 * @param y 修正值
	 * @param alpha 透明度
	 */
	public static void pressText(String pressText, String targetImg, String fontName, int fontStyle, Color color, int fontSize, int x, int y, float alpha) {
		try {
			File img = new File(targetImg);
			Image src = ImageIO.read(img);
			int width = src.getWidth(null);
			int height = src.getHeight(null);
			BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
			Graphics2D g = image.createGraphics();
			g.drawImage(src, 0, 0, width, height, null);
			g.setColor(color);
			g.setFont(new Font(fontName, fontStyle, fontSize));
			g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));
			g.drawString(pressText, (width - (getLength(pressText) * fontSize)) / 2 + x, (height - fontSize) / 2 + y);
			g.dispose();
			ImageIO.write((BufferedImage) image, "jpg", img);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}