Java實現 圖片水印或者文字水印

在原圖之上再畫一張圖片(drawImage)或者文本文字(drawString)，Java SE中提供了 java.awt.image包和javax.imageio包可以實現非常方便的實現 圖片水印或者文字水印。
1.圖片水印
如果你想學習java可以來這個羣，首先是一二六，中間是五三四，最後是五一九，裏面有大量的學習資料可以下載。
import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;

/**
* 生成圖片水印
* @author Ricky Fung
*
*/
public class WaterMarkIconTest {

/** 
 * @param args 
 */  
public static void main(String[] args) {  

    File srcImageFile = new File("D:/test/myblog.png");  
    File logoImageFile = new File("D:/test/logo.png");  

    File outputImageFile = new File("D:/test/myblog_water_icon.jpg");  
    File outputRoateImageFile = new File("D:/test/myblog_water_icon_rotate.jpg");  

    createWaterMarkByIcon(srcImageFile, logoImageFile, outputImageFile);  

    createWaterMarkByIcon(srcImageFile, logoImageFile, outputRoateImageFile, 45);  
}  

public static void createWaterMarkByIcon(File srcImageFile, File logoImageFile,  
        File outputImageFile) {  
    createWaterMarkByIcon(srcImageFile, logoImageFile, outputImageFile, 0);  
}  

public static void createWaterMarkByIcon(File srcImageFile, File logoImageFile,  
        File outputImageFile, double degree) {  

    OutputStream os = null;  
    try {  
        Image srcImg = ImageIO.read(srcImageFile);  

        BufferedImage buffImg = new BufferedImage(srcImg.getWidth(null),  
                srcImg.getHeight(null), BufferedImage.TYPE_INT_RGB);  

        Graphics2D g = buffImg.createGraphics();  

        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,  
                RenderingHints.VALUE_INTERPOLATION_BILINEAR);  

        g.drawImage(  
                srcImg.getScaledInstance(srcImg.getWidth(null),  
                        srcImg.getHeight(null), Image.SCALE_SMOOTH), 0, 0,  
                null);  

        ImageIcon logoImgIcon = new ImageIcon(ImageIO.read(logoImageFile));  

        Image logoImg = logoImgIcon.getImage();  

        //旋轉  
        if (degree>0) {  
            g.rotate(Math.toRadians(degree),  
                    (double) buffImg.getWidth() / 2,  
                    (double) buffImg.getWidth() / 2);  
        }  

        float alpha = 0.8f; // 透明度  
        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,  
                alpha));  

        //水印 的位置  
        g.drawImage(logoImg, buffImg.getWidth()/3, buffImg.getHeight()/2, null);  

        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));  

        g.dispose();  

        os = new FileOutputStream(outputImageFile);  

        // 生成圖片  
        ImageIO.write(buffImg, "JPG", os);  

    } catch (Exception e) {  
        e.printStackTrace();  
    } finally {  
        try {  
            if (null != os)  
                os.close();  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
}  

}

2.文字水印

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import javax.imageio.ImageIO;

/**
* 生成文字水印
* @author Ricky Fung
*
*/
public class WaterMarkTextTest {

/** 
 * @param args 
 */  
public static void main(String[] args) {  

    File srcImgFile = new File("D:/test/myblog.png");  
    String logoText = "[ 水印文字 電話邦   ]";  

    File outputImageFile = new File("D:/test/myblog_water_text.jpg");  

    File outputRotateImageFile = new File("D:/test/myblog_water_text_rotate.jpg");  

    createWaterMarkByText(srcImgFile, logoText, outputImageFile);  

    createWaterMarkByText(srcImgFile, logoText, outputRotateImageFile, 45);  
}  


public static void createWaterMarkByText(File srcImgFile, String logoText,  
        File outputImageFile) {  
    createWaterMarkByText(srcImgFile, logoText, outputImageFile, 0);  
}  

public static void createWaterMarkByText(File srcImgFile, String logoText,  
        File outputImageFile, double degree) {  

    OutputStream os = null;  
    try {  
        Image srcImg = ImageIO.read(srcImgFile);  

        BufferedImage buffImg = new BufferedImage(srcImg.getWidth(null),  
                srcImg.getHeight(null), BufferedImage.TYPE_INT_RGB);  

        Graphics2D g = buffImg.createGraphics();  

        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,  
                RenderingHints.VALUE_INTERPOLATION_BILINEAR);  

        g.drawImage(  
                srcImg.getScaledInstance(srcImg.getWidth(null),  
                        srcImg.getHeight(null), Image.SCALE_SMOOTH), 0, 0,  
                null);  

        if (degree>0) {  
            g.rotate(Math.toRadians(degree),  
                    (double) buffImg.getWidth() / 2,  
                    (double) buffImg.getHeight() / 2);  
        }  

        g.setColor(Color.RED);  

        g.setFont(new Font("宋體", Font.BOLD, 36));  

        float alpha = 0.8f;  
        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP,  
                alpha));  

        g.drawString(logoText, buffImg.getWidth()/3, buffImg.getHeight()/2);  

        g.dispose();  

        os = new FileOutputStream(outputImageFile);  

        // 生成圖片  
        ImageIO.write(buffImg, "JPG", os);  

    } catch (Exception e) {  
        e.printStackTrace();  
    } finally {  
        try {  
            if (null != os)  
                os.close();  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
}  

}