Spring Boot实现图片上传/加水印一把梭操作实例代码

2019-11-26 09:31:27

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概述

很多网站的图片为了版权考虑都加有水印，尤其是那些图片类网站。自己正好最近和图片打交道比较多，因此就探索了一番基于 Spring Boot这把利器来实现从图片上传 → 图片加水印的一把梭操作！

本文内容脑图如下：

本文内容脑图

搭建 Spring Boot基础工程

过程不再赘述了，这里给出 pom中的关键依赖：

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>commons-io</groupId><artifactId>commons-io</artifactId><version>2.5</version></dependency></dependencies>

编写文件上传服务

主要就是编写 ImageUploadService 服务

里面仅一个上传图片的方法：uploadImage 方法

/*** 功能：上传图片* @param file 文件* @param uploadPath 服务器上上传文件的路径* @param physicalUploadPath 服务器上上传文件的物理路径* @return 上传文件的 URL相对地址*/public String uploadImage( MultipartFile file, String uploadPath, String physicalUploadPath ) {String filePath = physicalUploadPath + file.getOriginalFilename();try {File targetFile=new File(filePath);FileUtils.writeByteArrayToFile(targetFile, file.getBytes());} catch (IOException e) {e.printStackTrace();}return uploadPath + "/" + file.getOriginalFilename();}}

编写图片加水印服务

编写 ImageWatermarkService 服务

里面就一个主要的 watermarkAdd方法，代码后面写有详细解释

@Servicepublic class ImageWatermarkService {/*** imgFile 图像文件* imageFileName 图像文件名* uploadPath 服务器上上传文件的相对路径* realUploadPath 服务器上上传文件的物理路径*/public String watermarkAdd( File imgFile, String imageFileName, String uploadPath, String realUploadPath ) {String imgWithWatermarkFileName = "watermark_" + imageFileName;OutputStream os = null;try {Image image = ImageIO.read(imgFile);int width = image.getWidth(null);int height = image.getHeight(null);BufferedImage bufferedImage = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); // ①Graphics2D g = bufferedImage.createGraphics(); // ②g.drawImage(image, 0, 0, width,height,null); // ③String logoPath = realUploadPath + "/" + Const.LOGO_FILE_NAME; // 水印图片地址File logo = new File(logoPath); // 读取水印图片Image imageLogo = ImageIO.read(logo);int markWidth = imageLogo.getWidth(null); // 水印图片的宽度和高度int markHeight = imageLogo.getHeight(null);g.setComposite( AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, Const.ALPHA) ); // 设置水印透明度g.rotate(Math.toRadians(-10), bufferedImage.getWidth()/2, bufferedImage.getHeight()/2); // 设置水印图片的旋转度int x = Const.X;int y = Const.Y;int xInterval = Const.X_INTERVAL;int yInterval = Const.Y_INTERVAL;double count = 1.5;while ( x < width*count ) { // 循环添加多个水印logoy = -height / 2;while( y < height*count ) {g.drawImage(imageLogo, x, y, null); // ④y += markHeight + yInterval;}x += markWidth + xInterval;}g.dispose();os = new FileOutputStream(realUploadPath + "/" + imgWithWatermarkFileName);JPEGImageEncoder en = JPEGCodec.createJPEGEncoder(os); // ⑤en.encode(bufferedImage); // ⑥} catch (Exception e) {e.printStackTrace();} finally {if(os!=null){try {os.close();} catch (IOException e) {e.printStackTrace();}}}return uploadPath + "/" + imgWithWatermarkFileName;}}

代码思路解释如下：

可以对照代码中的标示数字和下面的解释进行理解：

① 创建缓存图片

② 创建绘图工具

③ 将原图绘制到缓存图片

④ 将水印logo绘制到缓存图片

⑤ 创建图像编码工具类

⑥ 编码缓存图像生成目标图片

可见思路清晰易懂！

编写图片上传/处理控制器

我们在该控制器代码中将上述的图片上传服务和图片加水印服务给用起来：

@RestControllerpublic class WatermarkController {@Autowiredprivate ImageUploadService imageUploadService;@Autowiredprivate ImageWatermarkService watermarkService;@RequestMapping(value = "/watermarktest", method = RequestMethod.POST)public ImageInfo watermarkTest( @RequestParam("file") MultipartFile image ) {ImageInfo imgInfo = new ImageInfo();String uploadPath = "static/images/"; // 服务器上上传文件的相对路径String physicalUploadPath = getClass().getClassLoader().getResource(uploadPath).getPath(); // 服务器上上传文件的物理路径String imageURL = imageUploadService.uploadImage( image, uploadPath, physicalUploadPath );File imageFile = new File(physicalUploadPath + image.getOriginalFilename() );String watermarkAddImageURL = watermarkService.watermarkAdd(imageFile, image.getOriginalFilename(), uploadPath, physicalUploadPath);imgInfo.setImageUrl(imageURL);imgInfo.setLogoImageUrl(watermarkAddImageURL);return imgInfo;}}

实际实验与效果展示

我们用 Postman工具来辅助我们发出 localhost:9999/watermarktest 请求，进行图片上传的操作：

Postman发请求进行图片上传