springboot以http请求访问本地图片

如下图，本机(服务器)存储的图片想要在浏览器上通过Url地址访问：

1.上传

实现很简单，只需要利用拦截器将本机地址映射成url路径就行：

@Configuration
public class FilePathConfig implements WebMvcConfigurer {
    
    
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
    
    
        registry.addResourceHandler("/upload/**") //虚拟url路径
                .addResourceLocations("file:E:/image/"); //真实本地路径
    }
}

启动程序，输入本机Ip+端口+Url路径(替代了图片本地路径)+图片文件名：

尝试上传后再访问:

 public static final String host = "http://127.0.0.1:8080/upload/";


    @ApiOperation(value = "上传图片")
    @ApiImplicitParam(name = "file",value = "图片上传",required = true,dataTypeClass = MultipartFile.class,
            allowMultiple = true,paramType = "query")
    @PostMapping(value = "/upload")
    @ResponseBody
    public String insertOrderImg(@RequestParam("file") MultipartFile file) {
    
    
        // 文件上传路径
        String location = "E:\\image\\";

        String originalFilename = file.getOriginalFilename();
        String extName = originalFilename.substring(originalFilename.lastIndexOf("."));
        //设置允许上传文件类型
        String suffixList = ".jpg,.png,.ico,.bmp,.jpeg";
        String imgUrl=null;
        // 判断是否包含
        if (suffixList.contains(extName.trim().toLowerCase())) {
    
    
            // 保存文件的路径
            String path = location + originalFilename;
            //  spring的transferTo保存文件方法
            try {
    
    
                file.transferTo(new File(path));
                imgUrl = host + originalFilename;
            } catch (IOException e) {
    
    
                log.info("保存失败");
            }
        }
        return imgUrl;
    }

用knife4j上传图片成功并返回url地址：

2.压缩

使用Hutool或Thumbnails
引入依赖

<!--        图像处理依赖,包含了Thumbnails-->
        <dependency>
            <groupId>com.siashan</groupId>
            <artifactId>toolkit-image</artifactId>
            <version>1.1.1</version>
        </dependency>

public static final String host = "http://127.0.0.1:8080/upload/";


    @ApiOperation(value = "上传图片")
    @ApiImplicitParam(name = "file",value = "图片上传",required = true,dataTypeClass = MultipartFile.class,
            allowMultiple = true,paramType = "query")
    @PostMapping(value = "/upload")
    @ResponseBody
    public String insertOrderImg(@RequestParam("file") MultipartFile file) throws IOException {
    
    
        // 文件上传路径
        String location = "E:\\image\\";
        String originalFilename = file.getOriginalFilename();
        String extName = originalFilename.substring(originalFilename.lastIndexOf("."));
        //设置允许上传文件类型
        String suffixList = ".jpg,.png,.ico,.bmp,.jpeg";
        String imgUrl=null;
        // 判断是否包含
        if (suffixList.contains(extName.trim().toLowerCase())) {
    
    
            BufferedImage image = ImgUtil.read(file.getInputStream());
            int height = image.getHeight();
            int width = image.getWidth();
            // 保存文件的路径
            String path = location + originalFilename;
            // thumbnailator压缩存放路径
            String thumbPath= location+"thumbnailator"+originalFilename;
            //Img压缩存放路径
            String imgPath = location +"img"+ originalFilename;
            String newPath = location +"new"+ originalFilename;
            String shaValue = DigestUtil.sha256Hex(file.getBytes());
            //  spring的transferTo保存文件方法
            try {
    
    
                log.info("原图高{},宽{},大小{}KB",height,width,file.getSize()/1024);
                file.transferTo(new File(path));

                //Hutool图像编辑器压缩
                Img img = Img.from(file.getInputStream());
                Image img1 = img.scale(0.5f).setQuality(0.2f).getImg();
                byte[] bytes = ImgUtil.toBytes(img1, ImgUtil.IMAGE_TYPE_JPEG);
                log.info("Hutool压缩后高{},宽{},大小{}KB",img1.getHeight(null),img1.getWidth(null),bytes.length/1024);
                FileUtil.writeBytes(bytes,imgPath);

                //Thumbnails压缩 要读取压缩后图片大小和尺寸必须写后再读，没有Img编辑器压缩方便
                OutputStream outputStream1 = new FileOutputStream(thumbPath);
                Thumbnails.of(file.getInputStream())
                        .scale(0.5f)
                        .outputQuality(0.2f)
                        .toOutputStream(outputStream1);
                outputStream1.close();
                byte[] bytes1 = FileUtil.readBytes(thumbPath);
                BufferedImage read1 = ImgUtil.read(thumbPath);
                log.info("直接压缩高{},宽{},大小{}KB",read1.getHeight(),read1.getWidth(),bytes1.length/1024);

//                //Hutool另一种压缩方法，要读取压缩后图片大小和尺寸必须写后再读 ，没有Img编辑器压缩方便
//                OutputStream outputStream2 = new FileOutputStream(newPath);
//                ImageOutputStream imageOutputStream = ImgUtil.getImageOutputStream(outputStream2);
//                ImgUtil.scale(image, imageOutputStream, 0.5f);
//                ImgUtil.write(image,ImgUtil.IMAGE_TYPE_JPG,imageOutputStream,0.2F);
//                outputStream2.close();
//                byte[] bytes2 = FileUtil.readBytes(newPath);
//                BufferedImage read2 = ImgUtil.read(newPath);
//                log.info("Hutool直接压缩高{},宽{},大小{}KB",read2.getHeight(),read2.getWidth(),bytes2.length/1024);
                imgUrl = host + originalFilename;
            } catch (IOException e) {
    
    
                log.info("保存失败");
            }
        }
        return imgUrl;
    }

3.同一图片禁止重复

 public static final String host = "http://127.0.0.1:8080/upload/";

    public static final Map<String,String> imgMap= new ConcurrentHashMap<>();

    @ApiOperation(value = "上传图片")
    @ApiImplicitParam(name = "file",value = "图片上传",required = true,dataTypeClass = MultipartFile.class,
            allowMultiple = true,paramType = "query")
    @PostMapping(value = "/upload")
    @ResponseBody
    public String insertOrderImg(@RequestParam("file") MultipartFile file) throws IOException {
    
    
        // 文件上传路径
        String location = "E:\\image\\";
        String originalFilename = file.getOriginalFilename();
        String extName = originalFilename.substring(originalFilename.lastIndexOf("."));
        //设置允许上传文件类型
        String suffixList = ".jpg,.png,.ico,.bmp,.jpeg";
        String imgUrl=null;
        // 判断是否包含
        if (suffixList.contains(extName.trim().toLowerCase())) {
    
    
            BufferedImage image = ImgUtil.read(file.getInputStream());
            int height = image.getHeight();
            int width = image.getWidth();
            // 保存文件的路径
            String path = location + originalFilename;
            // thumbnailator压缩存放路径
            String thumbPath= location+"thumbnailator"+originalFilename;
            //Img压缩存放路径
            String imgPath = location +"img"+ originalFilename;
            String newPath = location +"new"+ originalFilename;
            //同一文件SHA256进行哈希运算后值唯一
            String shaValue = DigestUtil.sha256Hex(file.getBytes());
            if (imgMap.containsKey(shaValue)) {
    
    
                log.info("重复的SHA{},已上传的文件名{}",shaValue,imgMap.get(shaValue));
                return "已经上传,不可重复";
            }
            imgMap.put(shaValue,originalFilename);
            //  spring的transferTo保存文件方法
            try {
    
    
                log.info("原图高{},宽{},大小{}KB",height,width,file.getSize()/1024);
                file.transferTo(new File(path));

                //Hutool图像编辑器压缩
                Img img = Img.from(file.getInputStream());
                Image img1 = img.scale(0.5f).setQuality(0.2f).getImg();
                byte[] bytes = ImgUtil.toBytes(img1, ImgUtil.IMAGE_TYPE_JPEG);
                log.info("Hutool压缩后高{},宽{},大小{}KB",img1.getHeight(null),img1.getWidth(null),bytes.length/1024);
                FileUtil.writeBytes(bytes,imgPath);

                //Thumbnails压缩 要读取压缩后图片大小和尺寸必须写后再读，没有Img编辑器压缩方便
                OutputStream outputStream1 = new FileOutputStream(thumbPath);
                Thumbnails.of(file.getInputStream())
                        .scale(0.5f)
                        .outputQuality(0.2f)
                        .toOutputStream(outputStream1);
                outputStream1.close();
                byte[] bytes1 = FileUtil.readBytes(thumbPath);
                BufferedImage read1 = ImgUtil.read(thumbPath);
                log.info("Thumbnails压缩高{},宽{},大小{}KB",read1.getHeight(),read1.getWidth(),bytes1.length/1024);

//                //Hutool另一种压缩方法，要读取压缩后图片大小和尺寸必须写后再读 ，没有Img编辑器压缩方便
//                OutputStream outputStream2 = new FileOutputStream(newPath);
//                ImageOutputStream imageOutputStream = ImgUtil.getImageOutputStream(outputStream2);
//                ImgUtil.scale(image, imageOutputStream, 0.5f);
//                ImgUtil.write(image,ImgUtil.IMAGE_TYPE_JPG,imageOutputStream,0.2F);
//                outputStream2.close();
//                byte[] bytes2 = FileUtil.readBytes(newPath);
//                BufferedImage read2 = ImgUtil.read(newPath);
//                log.info("Hutool直接压缩高{},宽{},大小{}KB",read2.getHeight(),read2.getWidth(),bytes2.length/1024);
                imgUrl = host + originalFilename;
            } catch (IOException e) {
    
    
                log.info("保存失败");
            }
        }
        return imgUrl;
    }

第一次上传成功后继续上传：


同一张图片改名后上传：

同一张图片格式也更改后上传：

换其它图片上传：