springboot 实现单文件上传/多文件上传/文件下载

忘是亡心i 2023-08-17 16:56 178阅读 0赞

java 开发经常需要用到文件上传，接下来博主就创建一个springboot项目，实现单文件上传/多文件上传/文件下载功能

1.先看一下博主的项目结构图

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70][]

2.application.yml主要配置

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70 1][]

3.如上图创建项目

创建FileUpload类：

package com.study.controller;
    
    import lombok.extern.slf4j.Slf4j;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.multipart.MultipartFile;
    import org.springframework.web.multipart.MultipartHttpServletRequest;
    
    import javax.servlet.http.HttpServletRequest;
    import java.io.BufferedOutputStream;
    import java.io.File;
    import java.io.IOException;
    import java.util.List;
    
    @Slf4j
    @RestController
    @RequestMapping("/file")
    public class FileUpload {
        private static final Logger LOGGER = LoggerFactory.getLogger(FileUpload.class);
    
        @Value("${upload.path}")  //在application中配置的上传地址：
        private String uploadPath;
        @PostMapping("/upload")
        //单文件上传
        public Boolean upload(@RequestParam("file") MultipartFile file) {
            BufferedOutputStream stream = null;
            try {
                if (file.isEmpty()) {
                    LOGGER.info("文件为空：");
                    return false;
                }
                // 获取文件名
                String fileName = file.getOriginalFilename();
                LOGGER.info("上传的文件名为：" + fileName);
                // 获取文件的后缀名
                String suffixName = fileName.substring(fileName.lastIndexOf("."));
                LOGGER.info("文件的后缀名为：" + suffixName);
    
                File dest = new File(uploadPath + fileName);
                // 检测是否存在目录
                if (!dest.getParentFile().exists()) {
                    dest.getParentFile().mkdirs();
                }
                file.transferTo(dest);
                LOGGER.info("文件的上传路径：" + uploadPath);
                return true;
            } catch (IllegalStateException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return false;
        }
        //多文件上传
        @PostMapping("/uploadMore")
        public boolean handleFileUpload(HttpServletRequest request) {
            List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
            MultipartFile file = null;
            for (int i = 0; i < files.size(); ++i) {
                file = files.get(i);
                if (!file.isEmpty()) {
                    try {
                        String fileName = file.getOriginalFilename();
                        File dest = new File(uploadPath + fileName);
                        file.transferTo(dest);
                    } catch (Exception e) {
                        LOGGER.info("第{0}个文件上传失败 ==>{1} ",i,e.getMessage());
                        return false;
                    }
                } else {
                    LOGGER.info("第{0}个文件为空，上传失败 ",i);
                    return false;
                }
            }
            return true;
        }
    }

### 文件上传： ###

接下来使用接口测试工具postman测试：（注意：这里测试的单文件上传接口，多文件上传接口同理）

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70 2][]

### 查看上传文件： ###

![20190929224605347.png][]

###  文件下载： ###

1.配置拦截器，拦截器代码，在哪里配置请参考文章开始目录结构图

package com.study.controller.config;
    
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
    import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
    
    /**
     * 资源映射路径
     */
    @Configuration
    public class MyWebAppConfigurer implements WebMvcConfigurer {
        @Value("${upload.path}")  //application中配置的文件上传路径
        private String path;      
        @Value("${upload.staticPath}")  //application中配置的浏览器中的映射路径
        private String staticPath;
        @Override
        public void addResourceHandlers(ResourceHandlerRegistry registry) {
            //当用户访问http://localhost:8080/api/file/WeChat Image_20190928085046.jpg的时候
            //会把api/file映射为本地真实路径
            //这里会把上面这个访问地址映射为：
            //http://localhost:8080/G:/IdeaWorkSpace/MyStudyCollection/upload//WeChat //Image_20190928085046.jpg
            registry.addResourceHandler(staticPath +"/**").addResourceLocations("file:" + path);
        }
    }

启动项目访问：[http://localhost:8080/api/file/WeChat%20Image\_20190928085046.jpg（图片自动打开，其他文件提示下载）][http_localhost_8080_api_file_WeChat_20Image_20190928085046.jpg]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70 3][]

springboot实现单文件上传/多文件上传/文件下载就完成了

项目git地址：[https://gitee.com/Vince-ZZ/MyStudyCollection/tree/master/study-web][https_gitee.com_Vince-ZZ_MyStudyCollection_tree_master_study-web]

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![2019092922581479.jpeg][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70]: /images/20230809/54a14360b42846a4b5e543110e754ad5.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70 1]: /images/20230809/f1b0bd6528614321ae0d22d06c98cd50.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70 2]: /images/20230809/44ca552120394264a9b94446395d0dd7.png
[20190929224605347.png]: /images/20230809/4e8d5093d32e4b218ce66bc6b0fa1999.png
[http_localhost_8080_api_file_WeChat_20Image_20190928085046.jpg]: http://localhost:8080/api/file/WeChat%20Image_20190928085046.jpg
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0RyZWFtX3h1bg_size_16_color_FFFFFF_t_70 3]: /images/20230809/fd71115843064085812e49ac4c0ee0a4.png
[https_gitee.com_Vince-ZZ_MyStudyCollection_tree_master_study-web]: https://gitee.com/Vince-ZZ/MyStudyCollection/tree/master/study-web
[2019092922581479.jpeg]: /images/20230809/407f53b7aa1f42ac83456bf0fc405fca.png