java处理图片（添加水印）

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;

public class newImageTest {

public static void main(String[] args) throws IOException {

pressImage("c:\\test\\a2.jpg", "c:\\test\\a1.jpg", 0, 0, 0.5f);

pressText("我是文字水印", "c:\\test\\a1.jpg", "黑体", 36, Color.black, 80, 0, 0, 0.3f);

resize("c:\\test\\a1.jpg", 500, 500, true);

}

/**

* 图片水印

* @param pressImg 水印图片

* @param targetImg 目标图片

* @param x 修正值 默认在中间

* @param y 修正值 默认在中间

* @param alpha 透明度

*/

public final static void pressImage(String pressImg, String targetImg, int x, int y, float alpha) {

try {

File img = new File(targetImg);

Image src = ImageIO.read(img);

int wideth = src.getWidth(null);

int height = src.getHeight(null);

BufferedImage image = new BufferedImage(wideth, height, BufferedImage.TYPE_INT_RGB);

Graphics2D g = image.createGraphics();

g.drawImage(src, 0, 0, wideth, height, null);

//水印文件

Image src_biao = ImageIO.read(new File(pressImg));

int wideth_biao = src_biao.getWidth(null);

int height_biao = src_biao.getHeight(null);

g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));

g.drawImage(src_biao, (wideth - wideth_biao) / 2, (height - height_biao) / 2, wideth_biao, height_biao, null);

//水印文件结束

g.dispose();

ImageIO.write((BufferedImage) image, "jpg", img);

} catch (Exception e) {

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();

}

}

/**

* 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 = 0.0; //缩放比例

File f = new File(filePath);

BufferedImage bi = ImageIO.read(f);

Image itemp = bi.getScaledInstance(width, height, bi.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 int getLength(String text) {

int length = 0;

for (int i = 0; i < text.length(); i++) {

if (new String(text.charAt(i) + "").getBytes().length > 1) {

length += 2;

} else {

length += 1;

}

}

return length / 2;

}

}