restful批量上传文件_restful api上传文件（基础）-springboot

基于restful api格式的文件上传(只是上传到本地)：

packagecom.nxz.controller;importcom.nxz.entity.FileInfo;importorg.springframework.web.bind.annotation.PostMapping;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.RestController;importorg.springframework.web.multipart.MultipartFile;importjava.io.File;importjava.io.IOException;importjava.util.Date;

@RestController

@RequestMapping("/file")public classFileController {

@PostMappingpublic FileInfo update(MultipartFile file) throwsIOException {

System.out.println(file.getName());

System.out.println(file.getOriginalFilename());

System.out.println(file.getSize());

String holder= "G:\\0001-myproject\\mysecurity\\mysecurity-demo\\src\\main\\java\\com\\nxz\\controller";

File localFile= new File(holder, new Date().getTime() + ".txt");

file.transferTo(localFile);return newFileInfo(localFile.getAbsolutePath());

}

}

测试用例：

//伪造的mvc环境

@AutowiredprivateWebApplicationContext webApplicationContext;privateMockMvc mockMvc;

@Beforepublic voidbefore() {

mockMvc=MockMvcBuilders.webAppContextSetup(webApplicationContext).build();

}

@Testpublic void whenUploadSuccess() throwsException {

String file= mockMvc.perform(MockMvcRequestBuilders.fileUpload("/file")

.file(new MockMultipartFile("file", "test.txt", "multipart/form-data", "hello".getBytes("UTF-8"))))

.andExpect(MockMvcResultMatchers.status().isOk())

.andReturn().getResponse().getContentAsString();

System.out.println(file);

}

测试用例执行完之后输出文件绝对路径：

{"path":"G:\\mysecurity\\mysecurity-demo\\src\\main\\java\\com\\nxz\\controller\\1556463660034.txt"}

下载：

@GetMapping("/{id}")public voiddownLoad(@PathVariable String id,

HttpServletRequest request,

HttpServletResponse response)throwsIOException {

String holder= "G:\\0001-myproject\\mysecurity\\mysecurity-demo\\src\\main\\java\\com\\nxz\\controller";try(

InputStream inputStream= new FileInputStream(new File(holder, id + ".txt"));

OutputStream outputStream=response.getOutputStream();

) {

response.setContentType("application/x-download");

response.addHeader("Content-Disposition", "attachment;filename=test.txt");//重新定义下载后名称//将文件输入流复制到输出刘超过年 commons-io依赖

IOUtils.copy(inputStream, outputStream);

outputStream.flush();

}

}

访问：http://localhost:8080/user/1

springboot中上传文件：

java中和文件上传的类又两个：CommonsMultipartResolver，另一个就是StandardServletMultipartResolver，其中commonsMultipartResolver需要commons-fileupload支持，二StandardServletMultipartReslover是servlet3.0默认支持的，tomcat7以上版本就开始支持servlet7.0，springboot22.0之后支持的tomcat版本在7之后，因此是支持StandardServletMultipartReslover的

首先 springboot只要配置好pom(有spring-boot-starter-web依赖)，就能自动支持文件上传(包括单文件和多文件)，那么springboot中文件上传是怎样起作用的

1、pom依赖，下边这些依赖中，和配置文件上传有关的就是spring-boot-autoconfig依赖

org.springframework.boot

spring-boot-starter-web

---->>>

org.springframework.boot

spring-boot-starter

2.1.3.RELEASE

compile

---->>>>

org.springframework.boot

spring-boot-autoconfigure

2.1.3.RELEASE

compile

2、那么看下spring-boot-autoconfig jar包中的spring.factories文件中的内容，这个文件中全都是和springboot自动配置相关的类的全文件名，其中和文件上传有关的是

org.springframework.boot.autoconfigure.web.servlet.MultipartAutoConfiguration,\

3、进入这个类中(具体个各种autoconfiguration自动加载类是什么时候加载的，需要看springboot的启动来注解和启动类)

@Configuration

@ConditionalOnClass({ Servlet.class, StandardServletMultipartResolver.class,

MultipartConfigElement.class}) //这个注解表示存在servlet、StandardServletMultipartResolver、multipartConfigElement文件时才加载该类

@ConditionalOnProperty(prefix = "spring.servlet.multipart", name = "enabled", matchIfMissing = true)//配置文件的前缀

@ConditionalOnWebApplication(type =Type.SERVLET)//servlet @EnableConfigurationProperties(MultipartProperties.class)//配置文件类 public classMultipartAutoConfiguration { private finalMultipartProperties multipartProperties; publicMultipartAutoConfiguration(MultipartProperties multipartProperties) { this.multipartProperties =multipartProperties; } @Bean @ConditionalOnMissingBean({ MultipartConfigElement.class, CommonsMultipartResolver.class})//当没有commonsMultipartResolver文件时，初始化该bean publicMultipartConfigElement multipartConfigElement() { return this.multipartProperties.createMultipartConfig(); } @Bean(name =DispatcherServlet.MULTIPART_RESOLVER_BEAN_NAME) @ConditionalOnMissingBean(MultipartResolver.class) publicStandardServletMultipartResolver multipartResolver() { StandardServletMultipartResolver multipartResolver= newStandardServletMultipartResolver();//springboot默认的文件上传的类 multipartResolver.setResolveLazily(this.multipartProperties.isResolveLazily()); returnmultipartResolver; } }