java图片水印处理

水印处理工具方法

效果

代码

import lombok.extern.slf4j.Slf4j;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.Base64;
import java.util.Date;

/**
 * 图片添加水印
 */
@Slf4j
public class ImgWaterMark {

    // 水印透明度
    private  float alpha = 0.9f;
    // 水印文字大小
    private   int fontSize = 28;
    // 水印文字字体
    private  Font font =  new Font(Font.DIALOG, Font.PLAIN, this.fontSize);;
    // 水印文字颜色
    private  Color color = Color.black;
    // 水印之间的间隔
    private   int xmove = 200;
    // 水印之间的间隔
    private   int ymove = 200;

    private int  degree = -40;

    private String logoText;

    private ByteArrayOutputStream out;

    //rgb
    public static Color color(int v1,int v2,int v3){
        return new Color(v1,v2,v3);
    }
    //文字加时间
    public static String  timeText(String logoText){

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return logoText + sdf.format(new Date());
    }

    public ImgWaterMark(float alpha, int fontSize , Color color, int move, int degree, String logoText){
        this(logoText);
        this.alpha = alpha;
        this.fontSize = fontSize;
        this.font = new Font(Font.DIALOG, Font.PLAIN, this.fontSize);
        this.color = color;
        this.xmove = move;
        this.ymove = move;
        this.degree = degree;
    }

    public ImgWaterMark(String logoText){
        this();
        this.logoText = logoText;
    }

    public ImgWaterMark(){
        log.info("水印对象实例化");
        this.logoText = "水印测试";
        out = new ByteArrayOutputStream();
    }

    /**
     * 创建图片
     * @return
     */
    public ImgWaterMark create(InputStream in,String fileType) throws Exception {
        log.info("开始创建水印");
        try {
            Image source = ImageIO.read(in);
            int srcWidth = source.getWidth(null);
            int srcHeight = source.getHeight(null);

            BufferedImage buffImg = new BufferedImage(srcWidth,srcHeight, 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(source.getScaledInstance(srcWidth, srcHeight, Image.SCALE_SMOOTH),0, 0, null);
            // 设置水印旋转
            g.rotate(Math.toRadians(degree), (double) buffImg.getWidth() / 2, (double) buffImg.getHeight() / 2);

            // 设置水印文字颜色
            g.setColor(color);

            // 设置水印文字Font
            g.setFont(font);

            // 设置水印文字透明度
            g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha));

            int x = -srcWidth / 2;

            int y = -srcHeight / 2;

            int markWidth = fontSize * getTextLength(logoText);// 字体长度

            int markHeight = fontSize;// 字体高度

            // 循环添加水印
            while (x < srcWidth * 1.5) {

                y = -srcHeight / 2;

                while (y < srcHeight * 1.5) {

                    g.drawString(logoText, x, y);

                    y += markHeight + ymove;

                }

                x += markWidth + xmove;

            }

            // 释放资源
            g.dispose();

            ImageIO.write(buffImg,fileType,out);
            log.info("创建水印结束");
        } catch (IOException e) {
            throw new IOException("文件读取失败");
        }

        return this;
    }

    /**
     * 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;

    }


    public byte[] getData() throws IOException {
        byte[] data = out.toByteArray();
        out.flush();
        out.close();
        return data;
    }

    public String getDataBase64() throws IOException {
         return Base64.getEncoder().encodeToString(getData());
    }


}

测试代码

    public static void main(String[] args) throws Exception {
        FileInputStream fis = new FileInputStream("D:/imgtest/a.png");
        ImgWaterMark imgWaterMark = new ImgWaterMark();
        imgWaterMark.create(fis,"jpg");
        byte[] data = imgWaterMark.getData();
        System.out.println(data.length);
        FileOutputStream out = new FileOutputStream("D:/imgtest/b.png");
        out.write(data);
        out.flush();
        out.close();
    }
 

可以找个图片试一下哈