java给图片加水印

Posted 2022-06-30 可——叹——落叶飘零

以下提供两个方法

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.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;

public class TxtWatermark 
    // 水印透明度
    private static float alpha = 0.8f;
    // 水印文字大小
    public static final int FONT_SIZE = 20;
    // 水印文字颜色
    private static Color color = new Color(220,220,220);
 
    /**
     * 获取文本长度。汉字为1:1，英文和数字为2:1
     */
    private static int getTextLength (String text) 
        int length = text.length ();
        for (int i = 0; i < text.length (); i++) 
            String s = String.valueOf (text.charAt (i));
            if (s.getBytes ().length > 1) 
                length++;
            
        
        length = length % 2 == 0 ? length / 2 : length / 2 + 1;
        return length;
    
    /**
     * 给图片添加水印文字、可设置水印文字的旋转角度
     * 
     * @param logoText
     * @param srcImgPath
     * @param targerPath
     * 
     */
    public  static void ImageByMultipleText (String logoText, String srcImgPath, String targerPath) 
 
        InputStream is = null;
        OutputStream os = null;
        try 
            // 源图片
        	String suffix=srcImgPath.split("\\\\.")[1];
            Image srcImg = ImageIO.read (new File (srcImgPath));
            int width = srcImg.getWidth (null);// 原图宽度
            int height = srcImg.getHeight (null);// 原图高度
            BufferedImage buffImg = new BufferedImage (srcImg.getWidth (null), srcImg.getHeight (null),
                                                       BufferedImage.TYPE_INT_RGB);
            // 得到画笔对象
            Graphics2D g = buffImg.createGraphics ();
            // 设置对线段的锯齿状边缘处理
            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);
            // 设置水印旋转
            g.rotate (Math.toRadians(45));
            // 设置水印文字颜色
            g.setColor (color);
            // 设置水印文字Font
//            g.setFont (font);
            //计算字体大小以200像素为例  
            double multiple=1;
            if(width>548) 
            	multiple=width/548.8;
            else 
            	multiple=height/548.8;
            
            int newSize=(int) (FONT_SIZE*multiple);
            if(newSize<20) 
            	newSize=20;
            
            Font newFont = new Font ("微软雅黑", Font.BOLD, newSize);
            g.setFont(newFont);
            // 设置水印文字透明度
            g.setComposite (AlphaComposite.getInstance (AlphaComposite.SRC_ATOP, alpha));
            int markWidth = newSize * getTextLength (logoText);// 字体长度
            int rowsNumber = height/markWidth+1;
            int columnsNumber  = width/markWidth+1;
            if(rowsNumber<1) 
            	rowsNumber=1;
            
            if(columnsNumber<1) 
            	columnsNumber=1;
            
            // 循环添加水印
        	for(int j=0;j<rowsNumber;j++)
        		for(int i=0;i<columnsNumber;i++)
            		g.drawString(logoText, (int) (i*markWidth + j*markWidth + width*0.1), -i*markWidth + j*markWidth);//画出水印,并设置水印位置
            	
        	
            // 释放资源
            g.dispose ();
            // 生成图片
            os = new FileOutputStream (targerPath);
            ImageIO.write (buffImg, suffix, os);
            System.out.println ("添加水印文字成功!");
         catch (Exception e) 
            e.printStackTrace ();
         finally 
            try 
                if (null != is)
                    is.close ();
             catch (Exception e) 
                e.printStackTrace ();
            
            try 
                if (null != os)
                    os.close ();
             catch (Exception e) 
                e.printStackTrace ();
            
        
    
    
    /**
     * 给图片添加水印文字、可设置水印文字的旋转角度
     * 
     * @param logoText
     * @param srcImgPath
     * @param targerPath
     * 
     */
    public  static void ImageByMultipleText (String logoText,String suffix,InputStream is, OutputStream os) 
 
        try 
            // 源图片
            Image srcImg = ImageIO.read (is);
            int width = srcImg.getWidth (null);// 原图宽度
            int height = srcImg.getHeight (null);// 原图高度
            BufferedImage buffImg = new BufferedImage (srcImg.getWidth (null), srcImg.getHeight (null),
                                                       BufferedImage.TYPE_INT_RGB);
            // 得到画笔对象
            Graphics2D g = buffImg.createGraphics ();
            // 设置对线段的锯齿状边缘处理
            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);
            // 设置水印旋转
            g.rotate (Math.toRadians(45));
            // 设置水印文字颜色
            g.setColor (color);
            // 设置水印文字Font
//            g.setFont (font);
            //计算字体大小以200像素为例  
            double multiple=1;
            if(width>548) 
            	multiple=width/548.8;
            else 
            	multiple=height/548.8;
            
            int newSize=(int) (FONT_SIZE*multiple);
            if(newSize<20) 
            	newSize=20;
            
            Font newFont = new Font ("微软雅黑", Font.BOLD, newSize);
            g.setFont(newFont);
            // 设置水印文字透明度
            g.setComposite (AlphaComposite.getInstance (AlphaComposite.SRC_ATOP, alpha));
            int markWidth = newSize * getTextLength (logoText);// 字体长度
            int rowsNumber = height/markWidth+1;
            int columnsNumber  = width/markWidth+1;
            if(rowsNumber<1) 
            	rowsNumber=1;
            
            if(columnsNumber<1) 
            	columnsNumber=1;
            
            // 循环添加水印
        	for(int j=0;j<rowsNumber;j++)
        		for(int i=0;i<columnsNumber;i++)
            		g.drawString(logoText, (int) (i*markWidth + j*markWidth + width*0.1), -i*markWidth + j*markWidth);//画出水印,并设置水印位置
            	
        	
            // 释放资源
            g.dispose ();
            // 生成图片
            ImageIO.write (buffImg, suffix, os);
            System.out.println ("添加水印文字成功!");
         catch (Exception e) 
            e.printStackTrace ();