SpringBoot实现一个文件上传服务-白红宇

SpringBoot实现一个文件上传服务

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发布时间：2019-04-26

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文章目录

更新记录

2021/1/1 1:00 am 单文件上传实现
2020/1/1 16:30 pm 多文件上传实现，前端跨与请求配置

需求

文件上传，返回一个url,使用url可以直接访问该资源

上传文件存放在本机非SprngBoot项目静态资源位置

多文件上传

解决跨与请求

实现

配置application.yaml
定义一个存放上传文件的位置

web:  upload-path: /xxx/uploadFile/

单文件

controller

@RestControllerpublic class FileUploadController {
       @Value("${web.upload-path}")    String fileDir;    @PostMapping("upload")    public Map upload(MultipartFile file, HttpServletRequest request){
           String realPath = fileDir;        File folder= new File(realPath);        if (!folder.exists()){
               folder.mkdirs();        }        String oldName=file.getOriginalFilename();        String newName= UUID.randomUUID().toString()+oldName.substring(oldName.lastIndexOf("."));        Map
   
     result=new HashMap<>();        try {
               file.transferTo(new File(folder,newName));            String url=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+"/file/"+newName;            result.put("status","ok");            result.put("url",url);        } catch (IOException e) {
               result.put("status","failed");            result.put("msg",e.getMessage());        }        return result;    }}

上面的controller会返回给用户一个类似于http://localhost:8080/file/xxx.jpg

还需要配置资源请求映射才能正常访问到该服务

配置静态资源映射

@Configurationpublic class MyWebMvcConfig extends WebMvcConfigurationSupport {
       @Value("${web.upload-path}")    private String uploadFilePath;    @Override    public void addResourceHandlers(ResourceHandlerRegistry registry) {
           registry.addResourceHandler("/file/**").addResourceLocations("file:"+uploadFilePath);        //这句不要忘了，否则项目默认静态资源映射会失效        registry.addResourceHandler("/**").addResourceLocations("classpath:/static/");        super.addResourceHandlers(registry);    }}

多文件

@PostMapping("uploadMul")public Map upload(MultipartFile[] files, HttpServletRequest request){
       Map
   
     result=new HashMap<>();    int count=0;    List
    
     
      > list=new ArrayList<>();    if (files==null|| files.length==0){
           result.put("","failed");        result.put("msg","no file");        return result;    }    for (MultipartFile file : files) {
           Map
      
         map=new HashMap<>();        Map res = upload(file, request);        map.put("name",file.getOriginalFilename());        Object url = res.get("url");        if (url!=null){
               count++;            map.put("url",url);            map.put("status","ok");        }else {
               map.put("status","failed");            map.put("msg",res.get("msg"));        }        list.add(map);    }    result.put("upload",files.length);    result.put("succeed",count);    result.put("detail",list);    return result;}

跨域请求

跨域请求在后端配置即可

可以全局放行，也可以只针对某些地址允许

全局允许跨域请求

import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.cors.CorsConfiguration;import org.springframework.web.cors.UrlBasedCorsConfigurationSource;import org.springframework.web.filter.CorsFilter;@Configurationpublic class GlobalCorsConfig {
       @Bean    public CorsFilter corsFilter(){
           CorsConfiguration corsConfiguration = new CorsConfiguration();        corsConfiguration.addAllowedOrigin("*");        corsConfiguration.setAllowCredentials(false);        corsConfiguration.addAllowedMethod("*");        corsConfiguration.addAllowedHeader("*");        corsConfiguration.addExposedHeader("*");        UrlBasedCorsConfigurationSource configurationSource = new UrlBasedCorsConfigurationSource();        configurationSource.registerCorsConfiguration("/**",corsConfiguration);        return new CorsFilter(configurationSource);    }}