java--图片水印、压缩
有关图片增加水印图片、水印文字、图片压缩，代码如下：
源码来源于网上，稍作改动。
package com.test;import java.awt.AlphaComposite;import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.Image;import java.awt.geom.AffineTransform;import java.awt.image.AffineTransformOp;import java.awt.image.BufferedImage;import java.io.ByteArrayOutputStream;import java.io.File;import java.io.IOException;import javax.imageio.ImageIO;/** * 图片工具类， 图片水印，文字水印，缩放，补白等 * * @author gp */public final class WaterPress {/** 图片格式：JPG */private static final String PICTRUE_FORMATE_JPG = "jpg";private WaterPress() {}/** * 添加图片水印 * * @param targetImg * 目标图片路径，如：d:/1.jpg * @param waterImg * 水印图片路径，如：d:/2.png * @param x * 水印的横坐标 * @param y * 水印的纵坐标 * @param alpha * 透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明) */public final static void pressImage(String targetImg, String waterImg,int x, int y, float alpha) {try {File file = new File(targetImg);Image image = ImageIO.read(file);int width = image.getWidth(null);int height = image.getHeight(null);BufferedImage bufferedImage = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);Graphics2D g = bufferedImage.createGraphics();g.drawImage(image, 0, 0, width, height, null);Image waterImage = ImageIO.read(new File(waterImg)); // 水印文件int width_1 = waterImage.getWidth(null);int height_1 = waterImage.getHeight(null);g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,alpha));int widthDiff = width - width_1;int heightDiff = height - height_1;if (x < 0) {x = widthDiff / 2;} else if (x > widthDiff) {x = widthDiff;}if (y < 0) {y = heightDiff / 2;} else if (y > heightDiff) {y = heightDiff;}g.drawImage(waterImage, x, y, width_1, height_1, null); // 水印文件结束g.dispose();// 将已经做过水印处理的图片流写到本地ImageIO.write(bufferedImage, PICTRUE_FORMATE_JPG, new File("d://3.jpg"));} catch (IOException e) {e.printStackTrace();}}/** * 添加文字水印 * * @param targetImg * 目标图片路径，如：C://myPictrue//1.jpg * @param pressText * 水印文字， 如：中国证券网 * @param fontName * 字体名称， 如：宋体 * @param fontStyle * 字体样式，如：粗体和斜体(Font.BOLD|Font.ITALIC) * @param fontSize * 字体大小，单位为像素 * @param color * 字体颜色 * @param x * 水印文字距离目标图片左侧的偏移量，如果x<0, 则在正中间 * @param y * 水印文字距离目标图片上侧的偏移量，如果y<0, 则在正中间 * @param alpha * 透明度(0.0 -- 1.0, 0.0为完全透明，1.0为完全不透明) */public static void pressText(String targetImg, String pressText,String fontName, int fontStyle, int fontSize, Color color, int x,int y, float alpha) {try {File file = new File(targetImg);Image image = ImageIO.read(file);int width = image.getWidth(null);int height = image.getHeight(null);BufferedImage bufferedImage = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);Graphics2D g = bufferedImage.createGraphics();g.drawImage(image, 0, 0, width, height, null);g.setFont(new Font(fontName, fontStyle, fontSize));g.setColor(color);g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,alpha));int width_1 = fontSize * getLength(pressText);int height_1 = fontSize;int widthDiff = width - width_1;int heightDiff = height - height_1;if (x < 0) {x = widthDiff / 2;} else if (x > widthDiff) {x = widthDiff;}if (y < 0) {y = heightDiff / 2;} else if (y > heightDiff) {y = heightDiff;}g.drawString(pressText, x, y + height_1);g.dispose();ImageIO.write(bufferedImage, PICTRUE_FORMATE_JPG, new File("d://4.jpg"));} catch (Exception e) {e.printStackTrace();}}/** * 获取字符长度，一个汉字作为 1 个字符, 一个英文字母作为 0.5 个字符 * * @param text * @return 字符长度，如：text="中国",返回 2；text="test",返回 2；text="中国ABC",返回 4. */public static int getLength(String text) {int textLength = text.length();int length = textLength;for (int i = 0; i < textLength; i++) {if (String.valueOf(text.charAt(i)).getBytes().length > 1) {length++;}}return (length % 2 == 0) ? length / 2 : length / 2 + 1;}/** * 图片缩放 * * @param filePath * 图片路径 * @param height * 高度 * @param width * 宽度 * @param bb * 比例不对时是否需要补白 */public static void resize(String filePath, int height, int width, boolean bb) {try {double ratio = 0; // 缩放比例File f = new File(filePath);BufferedImage bi = ImageIO.read(f);Image itemp = bi.getScaledInstance(width, height,BufferedImage.SCALE_SMOOTH);// 计算比例if ((bi.getHeight() > height) || (bi.getWidth() > width)) {if (bi.getHeight() > bi.getWidth()) {ratio = (new Integer(height)).doubleValue()/ bi.getHeight();} else {ratio = (new Integer(width)).doubleValue() / bi.getWidth();}AffineTransformOp op = new AffineTransformOp(AffineTransform.getScaleInstance(ratio, ratio), null);itemp = op.filter(bi, null);}if (bb) {BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);Graphics2D g = image.createGraphics();g.setColor(Color.white);g.fillRect(0, 0, width, height);if (width == itemp.getWidth(null))g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2,itemp.getWidth(null), itemp.getHeight(null),Color.white, null);elseg.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0,itemp.getWidth(null), itemp.getHeight(null),Color.white, null);g.dispose();itemp = image;}ImageIO.write((BufferedImage) itemp, "jpg", new File("d://5.jpg"));} catch (IOException e) {e.printStackTrace();}}public static void main(String[] args) throws IOException {// 打水印图片pressImage("d://1.jpg", "d://2.png", 400, 1500, 0.5f);// 打水印文字pressText("d://1.jpg", "GP之印", "宋体", Font.BOLD | Font.ITALIC, 60,Color.YELLOW, 400, 100, 1f);// 图片压缩resize("d://1.jpg", 1000, 500, true);}}