Java给图片添加文字水印

package com.test;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;


public class WatermarkUtil {

    
    public static void addTextWatermark(File srcFile, String text, Font font, Color color) throws IOException {
        //文件转图片
        Image image = ImageIO.read(srcFile);

        //获取图片尺寸
        int width = image.getWidth(null), height = image.getHeight(null);

        //创建空的画布
        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        //创建画笔
        Graphics2D g = bufferedImage.createGraphics();

        //把图片画在画布上, x和y是开始画的位置，这里是左上角(0,0)
        g.drawImage(image, 0, 0, width, height, null);

        //设置水印字体和颜色
        g.setFont(font);
        g.setColor(color);
        //设置透明度
        g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 0.5f));

        //计算水印位置-右下角：英文
        //int h = height-font.getSize(), w = width-text.length()*font.getSize()/2-10;
        //计算水印位置-右下角：中文
        int h = height-font.getSize(), w = width-text.length()*font.getSize()-10;

        //画水印
        g.drawString(text, w, h);

        //释放资源
        g.dispose();

        String fileFullName = srcFile.getName();
        int splitIndex = fileFullName.lastIndexOf(".");
        String fileName = fileFullName.substring(0, splitIndex);
        String extName = fileFullName.substring(splitIndex + 1);

        //写入本地磁盘， 使用时按具体情况处理
        ImageIO.write(bufferedImage, extName, new File("D:\test\"+fileName+"_watermark."+extName));

    }
}

public static void main(String[] args) throws IOException{
    File file = new File("D:\test\src.jpg");
    WatermarkUtil.addTextWatermark(file, "我是水印", new Font("黑体", 0, 20), new Color(248,0,0));
}