实例代码：
package com.tzz.util;
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.File;
import java.io.IOException;
import javax.imageio.ImageIO;
/**
* 图片工具类， 图片水印，文字水印，缩放
*/
public final class ImageUtils {
/** 图片格式：JPG */
private static final String PICTRUE_FORMATE_JPG = "jpg";
/**
* 添加图片水印
*
* @param targetImg
* 目标图片路径
* @param waterImg
* 水印图片路径
* @param x
* 水印图片距离目标图片左侧的偏移量，如果x<0, 则在正中间
* @param y
* 水印图片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 final static void addImageWeatermark(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();
ImageIO.write(bufferedImage, PICTRUE_FORMATE_JPG, file);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 添加文字水印
*
* @param targetImg
* 目标图片路径
* @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 addTextWeatermark(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, file);
} 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);
else
g.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", f);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 图片合并(将两张图片合并为一张图片)
*
* @param oneSrc
* @param twoSrc
* @param mergeSrc
* 合并后的图片路径
*/
public static void mergeImage(String oneSrc, String twoSrc, String mergeSrc) {
String postFix = mergeSrc.substring(mergeSrc.lastIndexOf(".") + 1, mergeSrc.length());
try {
File fileOne = new File(oneSrc);// 读取第一张图片
Image src = ImageIO.read(fileOne);
int width = src.getWidth(null);
int height = src.getHeight(null);
if (width > 900 || height > 900) {
int num = (int) Math.ceil((double) width / 900);
int num2 = (int) Math.ceil((double) height / 900);
num = num > num2 ? num : num2;
width = width / num;
height = height / num;
}
BufferedImage bufferedImageOne = null;
if ("png".equalsIgnoreCase(postFix.toLowerCase())) {
bufferedImageOne = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR);
} else {
bufferedImageOne = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
}
bufferedImageOne.getGraphics().drawImage(src.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0,
null);
int[] imageArrayOne = new int[width * height];// 从图片中读取RGB
imageArrayOne = bufferedImageOne.getRGB(0, 0, width, height, imageArrayOne, 0, width);
File fileTwo = new File(twoSrc);// 读取第二张图片
src = ImageIO.read(fileTwo);
BufferedImage bufferedImageTwo = null;
if ("png".equalsIgnoreCase(postFix.toLowerCase())) {
bufferedImageTwo = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR);
} else {
bufferedImageTwo = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
}
bufferedImageTwo.getGraphics().drawImage(src.getScaledInstance(width, height, Image.SCALE_SMOOTH), 0, 0,
null);
int[] imageArrayTwo = new int[width * height];// 从图片中读取RGB
imageArrayTwo = bufferedImageTwo.getRGB(0, 0, width, height, imageArrayTwo, 0, width);
// 生成新图片
BufferedImage imageNew = new BufferedImage(width * 2, height, BufferedImage.TYPE_INT_RGB);
imageNew.setRGB(0, 0, width, height, imageArrayOne, 0, width); // 设置左半部分的RGB
imageNew.setRGB(width, 0, width, height, imageArrayTwo, 0, width); // 设置右半部分的RGB
File outFile = new File(mergeSrc);
// 写图片
ImageIO.write(imageNew, postFix, outFile);
} catch (Exception e) {
e.printStackTrace();
}
}
}
测试：
package com.tzz.test.util;
import java.awt.Color;
import java.awt.Font;
import org.junit.Test;
import com.tzz.util.ImageUtils;
public class ImageUtilsTest {
/**测试图片合并*/
@Test
public void testMergeImage(){
ImageUtils.mergeImage("D:/1.jpg", "D:/2.png", "D:/3.png");
}
/**测试添加图片水印*/
@Test
public void testAddImageWeatermark(){
ImageUtils.addImageWeatermark("D:/imageWeatermark.jpg", "D:/test.jpg", 10, 10, 0f);
}
/**测试添加文字水印*/
@Test
public void testAddTextWeatermark(){
ImageUtils.addTextWeatermark("D:/textWeatermark.jpg", "添加文本水印", "宋体", Font.BOLD | Font.ITALIC, 20, Color.BLACK, 0, 0, 8f);
}
/**图片缩放*/
@Test
public void testResize(){
ImageUtils.resize("D:/resize1.jpg", 1000, 500, true);
}
}