JAVA实用案例之图片水印开发

写在最前面

上周零零碎碎花了一周的时间研究水印的开发,现在终于写了个入门级的Demo,做下笔记同时分享出来供大家参考。

Demo是在我上次写的 JAVA实用案例之文件导入导出(POI方式) 框架基础上搭建的,基于Spring+SpringMVC。如果有错误还请大家指正。

最后源码地址在:https://github.com/allanzhuo/myport.git 。转载还请注明出处:http://www.cnblogs.com/allanzhang/p/7193309.html

简单介绍

水印开发是web开发中一种比较常见的功能,实现的代码很简单,具体的实现步骤我也会以代码为基础详细讲述。其实以我个人的理解,我把水印的类型和开发流程分为以下几种。

水印的类型:

  • 单文字水印
  • 单图片水印
  • 多文字水印
  • 多图片水印

水印的开发流程:

  1. 创建图片缓存对象
  2. 创建Java绘图工具对象
  3. 使用绘图工具工具对象将原图绘制到缓存图片对象
  4. 使用绘图工具对象将水印(文字/图片)绘制到缓存图片
  5. 创建图像编码工具类
  6. 使用图像编码工具类,输出缓存图像到目标文件

效果图:

上传页:

image

原图:

image

单文字水印:

image

单图片水印:

image

多文字水印:

image

多图片水印:

image

单文字水印开发

所谓单文字水印,就是在一张图片上添加一条文字水印。其中我们主要的流程是通过ImageIO工具类解码对应的图片,然后创建BufferImage对象,通过BufferImage对象创建Graphics2D对象,再通过Graphics2D对象绘制原图到BufferImage对象。然后,我们还可以使用Graphics2D对象来设置水印的相关信息,如水印内容、字体大小、字体风格等。
这里需要说明的是我们需要计算水印文本的宽度,中文长度即文本宽度,英文长度为文本宽度的二分之一。具体可以参考我源码中的相关内容。

    //计算水印文本长度
    //1、中文长度即文本长度 2、英文长度为文本长度二分之一
    public int getTextLength(String text){
        //水印文字长度
        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;
    }
   //添加单条文字水印方法
    public String textWaterMark(MultipartFile myFile,String imageFileName) {
        InputStream is =null;
        OutputStream os =null;
        int X = 636;
        int Y = 700;

        try {
            //使用ImageIO解码图片
            Image image = ImageIO.read(myFile.getInputStream());
            //计算原始图片宽度长度
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            //创建图片缓存对象
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
            //创建java绘图工具对象
            Graphics2D graphics2d = bufferedImage.createGraphics();
            //参数主要是,原图,坐标,宽高
            graphics2d.drawImage(image, 0, 0, width, height, null);
            graphics2d.setFont(new Font(FONT_NAME, FONT_STYLE, FONT_SIZE));
            graphics2d.setColor(FONT_COLOR);

            //使用绘图工具将水印绘制到图片上
            //计算文字水印宽高值
            int waterWidth = FONT_SIZE*getTextLength(MARK_TEXT);
            int waterHeight = FONT_SIZE;
            //计算水印与原图高宽差
            int widthDiff = width-waterWidth;
            int heightDiff = height-waterHeight;
            //水印坐标设置
            if (X > widthDiff) {
                X = widthDiff;
            }
            if (Y > heightDiff) {
                Y = heightDiff;
            }
            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            //纵坐标在下方,不增加字体高度会靠上
            graphics2d.drawString(MARK_TEXT, X, Y+FONT_SIZE);

            graphics2d.dispose();
            os = new FileOutputStream(UPLOAD_PATH+"/"+imageFileName);
            //创建图像编码工具类
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            //使用图像编码工具类,输出缓存图像到目标文件
            en.encode(bufferedImage);
            if(is!=null){       
                is.close();
            }
            if(os!=null){
                os.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "success";
    }

单图片水印开发

单图片水印和上面单文字的代码流程大致一致,这里只讲解不同之处。
首先我们需要获得水印图片的路径,然后创建水印文件对象,同样通过ImageIO工具类解码水印图片,中间我们就不需要计算文本长宽了,因为单文字中的长宽即是我们水印图片的长宽。

            //水印图片路径
            //水印坐标设置
            String logoPath = "/img/logo.png";
            String realPath = request.getSession().getServletContext().getRealPath(logoPath);
            File logo = new File(realPath);
            Image imageLogo = ImageIO.read(logo);
            int widthLogo = imageLogo.getWidth(null);
            int heightLogo = imageLogo.getHeight(null);
            int widthDiff = width-widthLogo;
            int heightDiff = height-heightLogo;
            //水印坐标设置
            if (X > widthDiff) {
                X = widthDiff;
            }
            if (Y > heightDiff) {
                Y = heightDiff;
            }
            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            graphics2d.drawImage(imageLogo, X, Y, null);

多文字水印开发

其实多文字水印开发和单文字也是类似的,主要的不同点是我们需要将BufferImage对象进行旋转。因为绘制水印并不支持旋转水印绘制,所以我们需要对原图进行旋转绘制,然后通过循环,我们就可以将一个文字水印多次绘制在原图上了。

            //旋转原图,注意旋转角度为弧度制。后面两个参数为旋转的坐标中心
            graphics2d.rotate(Math.toRadians(30), bufferedImage.getWidth()/2, bufferedImage.getHeight()/2);

            int x = -width/2;
            int y = -height/2;

            while(x < width*1.5){
                y = -height/2;
                while(y < height*1.5){
                    graphics2d.drawString(MARK_TEXT, x, y);
                    y+=waterHeight+100;
                }
                x+=waterWidth+100;
            }

多图片水印开发

与上文相同,多图片水印需要先读取水印图片,然后对水印设置透明度,在对原图进行旋转,然后通过循环,我们就可以将一个图片水印多次绘制在原图上。

            //水印图片路径
            String logoPath = "/img/logo.png";
            String realPath = request.getSession().getServletContext().getRealPath(logoPath);
            File logo = new File(realPath);
            Image imageLogo = ImageIO.read(logo);
            int widthLogo = imageLogo.getWidth(null);
            int heightLogo = imageLogo.getHeight(null);
            
            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            
            graphics2d.rotate(Math.toRadians(30), bufferedImage.getWidth()/2, bufferedImage.getHeight()/2);
            
            int x = -width/2;
            int y = -height/2;

            while(x < width*1.5){
                y = -height/2;
                while(y < height*1.5){
                    graphics2d.drawImage(imageLogo, x, y, null);
                    y+=heightLogo+100;
                }
                x+=widthLogo+100;
            }

业务类完整代码:

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import com.allan.service.WaterMarkService;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
@Service
public class WaterMarkServiceImpl implements WaterMarkService{
    //定义上传的文件夹
    private static final String UPLOAD_PATH = "E:/save";
    //定义水印文字样式
    private static final String MARK_TEXT = "小卖铺的老爷爷";
    private static final String FONT_NAME = "微软雅黑";
    private static final int FONT_STYLE = Font.BOLD;
    private static final int FONT_SIZE = 60;
    private static final Color FONT_COLOR = Color.black;


    private static final float ALPHA = 0.3F;


    //1、上传图片
    public String uploadImage(MultipartFile myFile,String imageFileName) {
        InputStream is =null;
        OutputStream os =null;
        try{
            is = myFile.getInputStream();
            os = new FileOutputStream(UPLOAD_PATH+"/"+imageFileName);
            byte[] buffer =new byte[1024];
            int len = 0;

            while ((len=is.read(buffer))>0){
                os.write(buffer);
            }

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

                    e.printStackTrace();
                }
            }
            if(os!=null){
                try {
                    os.close();
                } catch (IOException e2) {
                    e2.printStackTrace();
                }
            }
        }

        return "success";

    }
    //添加单条文字水印
    public String textWaterMark(MultipartFile myFile,String imageFileName) {
        InputStream is =null;
        OutputStream os =null;
        int X = 636;
        int Y = 700;

        try {
            Image image = ImageIO.read(myFile.getInputStream());
            //计算原始图片宽度长度
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            //创建图片缓存对象
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
            //创建java绘图工具对象
            Graphics2D graphics2d = bufferedImage.createGraphics();
            //参数主要是,原图,坐标,宽高
            graphics2d.drawImage(image, 0, 0, width, height, null);
            graphics2d.setFont(new Font(FONT_NAME, FONT_STYLE, FONT_SIZE));
            graphics2d.setColor(FONT_COLOR);

            //使用绘图工具将水印绘制到图片上
            //计算文字水印宽高值
            int waterWidth = FONT_SIZE*getTextLength(MARK_TEXT);
            int waterHeight = FONT_SIZE;
            //计算水印与原图高宽差
            int widthDiff = width-waterWidth;
            int heightDiff = height-waterHeight;
            //水印坐标设置
            if (X > widthDiff) {
                X = widthDiff;
            }
            if (Y > heightDiff) {
                Y = heightDiff;
            }
            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            graphics2d.drawString(MARK_TEXT, X, Y+FONT_SIZE);

            graphics2d.dispose();
            os = new FileOutputStream(UPLOAD_PATH+"/"+imageFileName);
            //创建图像编码工具类
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            //使用图像编码工具类,输出缓存图像到目标文件
            en.encode(bufferedImage);
            if(is!=null){       
                is.close();
            }
            if(os!=null){
                os.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "success";
    }

    //添加单图片水印
    public String imageWaterMark(MultipartFile myFile,String imageFileName,HttpServletRequest request) {
        InputStream is =null;
        OutputStream os =null;
        int X = 636;
        int Y = 763;

        try {
            Image image = ImageIO.read(myFile.getInputStream());
            //计算原始图片宽度长度
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            //创建图片缓存对象
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
            //创建java绘图工具对象
            Graphics2D graphics2d = bufferedImage.createGraphics();
            //参数主要是,原图,坐标,宽高
            graphics2d.drawImage(image, 0, 0, width, height, null);
            graphics2d.setFont(new Font(FONT_NAME, FONT_STYLE, FONT_SIZE));
            graphics2d.setColor(FONT_COLOR);

            //水印图片路径
            String logoPath = "/img/logo.png";
            String realPath = request.getSession().getServletContext().getRealPath(logoPath);
            File logo = new File(realPath);
            Image imageLogo = ImageIO.read(logo);
            int widthLogo = imageLogo.getWidth(null);
            int heightLogo = imageLogo.getHeight(null);
            int widthDiff = width-widthLogo;
            int heightDiff = height-heightLogo;
            //水印坐标设置
            if (X > widthDiff) {
                X = widthDiff;
            }
            if (Y > heightDiff) {
                Y = heightDiff;
            }
            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            graphics2d.drawImage(imageLogo, X, Y, null);

            graphics2d.dispose();
            os = new FileOutputStream(UPLOAD_PATH+"/"+imageFileName);
            //创建图像编码工具类
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            //使用图像编码工具类,输出缓存图像到目标文件
            en.encode(bufferedImage);
            if(is!=null){       
                is.close();
            }
            if(os!=null){
                os.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "success";
    }
    //添加多条文字水印
    public String moreTextWaterMark(MultipartFile myFile,String imageFileName) {
        InputStream is =null;
        OutputStream os =null;
        int X = 636;
        int Y = 763;

        try {
            Image image = ImageIO.read(myFile.getInputStream());
            //计算原始图片宽度长度
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            //创建图片缓存对象
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
            //创建java绘图工具对象
            Graphics2D graphics2d = bufferedImage.createGraphics();
            //参数主要是,原图,坐标,宽高
            graphics2d.drawImage(image, 0, 0, width, height, null);
            graphics2d.setFont(new Font(FONT_NAME, FONT_STYLE, FONT_SIZE));
            graphics2d.setColor(FONT_COLOR);

            //使用绘图工具将水印绘制到图片上
            //计算文字水印宽高值
            int waterWidth = FONT_SIZE*getTextLength(MARK_TEXT);
            int waterHeight = FONT_SIZE;

            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            graphics2d.rotate(Math.toRadians(30), bufferedImage.getWidth()/2, bufferedImage.getHeight()/2);

            int x = -width/2;
            int y = -height/2;

            while(x < width*1.5){
                y = -height/2;
                while(y < height*1.5){
                    graphics2d.drawString(MARK_TEXT, x, y);
                    y+=waterHeight+100;
                }
                x+=waterWidth+100;
            }
            graphics2d.dispose();

            os = new FileOutputStream(UPLOAD_PATH+"/"+imageFileName);
            //创建图像编码工具类
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            //使用图像编码工具类,输出缓存图像到目标文件
            en.encode(bufferedImage);
            if(is!=null){       
                is.close();
            }
            if(os!=null){
                os.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "success";
    }

    //多图片水印
    public String moreImageWaterMark(MultipartFile myFile,String imageFileName,HttpServletRequest request) {
        InputStream is =null;
        OutputStream os =null;
        int X = 636;
        int Y = 763;

        try {
            Image image = ImageIO.read(myFile.getInputStream());
            //计算原始图片宽度长度
            int width = image.getWidth(null);
            int height = image.getHeight(null);
            //创建图片缓存对象
            BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); 
            //创建java绘图工具对象
            Graphics2D graphics2d = bufferedImage.createGraphics();
            //参数主要是,原图,坐标,宽高
            graphics2d.drawImage(image, 0, 0, width, height, null);
            graphics2d.setFont(new Font(FONT_NAME, FONT_STYLE, FONT_SIZE));
            graphics2d.setColor(FONT_COLOR);

            //水印图片路径
            String logoPath = "/img/logo.png";
            String realPath = request.getSession().getServletContext().getRealPath(logoPath);
            File logo = new File(realPath);
            Image imageLogo = ImageIO.read(logo);
            int widthLogo = imageLogo.getWidth(null);
            int heightLogo = imageLogo.getHeight(null);
            
            //水印透明设置
            graphics2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, ALPHA));
            
            graphics2d.rotate(Math.toRadians(30), bufferedImage.getWidth()/2, bufferedImage.getHeight()/2);
            
            int x = -width/2;
            int y = -height/2;

            while(x < width*1.5){
                y = -height/2;
                while(y < height*1.5){
                    graphics2d.drawImage(imageLogo, x, y, null);
                    y+=heightLogo+100;
                }
                x+=widthLogo+100;
            }
            graphics2d.dispose();
            os = new FileOutputStream(UPLOAD_PATH+"/"+imageFileName);
            //创建图像编码工具类
            JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os);
            //使用图像编码工具类,输出缓存图像到目标文件
            en.encode(bufferedImage);
            if(is!=null){       
                is.close();
            }
            if(os!=null){
                os.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "success";
    }

    //计算水印文本长度
    //1、中文长度即文本长度 2、英文长度为文本长度二分之一
    public int getTextLength(String text){
        //水印文字长度
        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;
    }
}

最后再说明下,本Demo是在上次的文件导入导出的框架基础上编写的,源码中有些其它Demo的代码,本文主要使用的类有WaterMarkController.javaWaterMarkService.javaWaterMarkServiceImpl.java,因为代码中我是硬编码到E:/save文件夹下的,如果要运行的话,还请先新建此文件夹,或者改为其他文件夹也行。
源码地址:https://github.com/allanzhuo/myport.git

posted @ 2017-07-17 11:53 小卖铺的老爷爷 阅读(...) 评论(...) 编辑 收藏


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