Java水印图片处理

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，补白等
*
* @author Carl He
*/
public final class ImageUtils {
/** 图片格式：JPG */
private static final String PICTRUE_FORMATE_JPG = "jpg";

private ImageUtils() {
}

/**
* 添加图片水印
*
* @param targetImg
*            目标图片路径，如：C://myPictrue//1.jpg
* @param waterImg
*            水印图片路径，如：C://myPictrue//logo.png
* @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 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();
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，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, 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();
}
}

public static void main(String[] args) throws IOException {
pressImage("C://pic//jpg", "C://pic//test.gif", 5000, 5000, 0f);
pressText("C://pic//jpg", "旺仔之印", "宋体", Font.BOLD | Font.ITALIC, 20,
Color.BLACK, 0, 0, 8f);
resize("C://pic//4.jpg", 1000, 500, true);
}
}