这篇“怎么用Spring Cloud Feign实现文件上传下载”文章的知识点大部分人都不太理解，所以小编给大家总结了以下内容，内容详细，步骤清晰，具有一定的借鉴价值，希望大家阅读完这篇文章能有所收获，下面我们一起来看看这篇“怎么用Spring Cloud Feign实现文件上传下载”文章吧。
Feign框架对于文件上传消息体格式并没有做原生支持，需要集成模块feign-form来实现。
独立使用Feign
添加模块依赖：
<!-- Feign框架核心 --><dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-core</artifactId> <version>11.1</version></dependency><!-- 支持表单格式，文件上传格式 --><dependency> <groupId>io.github.openfeign.form</groupId> <artifactId>feign-form</artifactId> <version>3.8.0</version></dependency><!-- 文件操作工具类 --><dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.11.0</version></dependency>上传文件
定义接口：
public interface FileUploadAPI { // 上传文件：参数为单个文件对象 @RequestLine("POST /test/upload/single") @Headers("Content-Type: multipart/form-data") String upload(@Param("file") File file); // 上传文件：参数文多个文件对象 @RequestLine("POST /test/upload/batch") @Headers("Content-Type: multipart/form-data") String upload(@Param("files") File[] files); // 上传文件：参数文多个文件对象 @RequestLine("POST /test/upload/batch") @Headers("Content-Type: multipart/form-data") String upload(@Param("files") List<File> files); // 上传文件：参数为文件字节数组（这种方式在服务端无法获取文件名，不要使用） @RequestLine("POST /test/upload/single") @Headers("Content-Type: multipart/form-data") String upload(@Param("file") byte[] bytes); // 上传文件：参数为FormData对象 @RequestLine("POST /test/upload/single") @Headers("Content-Type: multipart/form-data") String upload(@Param("file") FormData photo); // 上传文件：参数为POJO对象 @RequestLine("POST /test/upload/single") @Headers("Content-Type: multipart/form-data") String upload(@Param("file") MyFile myFile); class MyFile { @FormProperty("is_public") Boolean isPublic; File file; public Boolean getPublic() { return isPublic; } public void setPublic(Boolean aPublic) { isPublic = aPublic; } public File getFile() { return file; } public void setFile(File file) { this.file = file; } }}调用接口：
FileAPI fileAPI = Feign.builder() .encoder(new FormEncoder()) // 必须明确设置请求参数编码器 .logger(new Slf4jLogger()) .logLevel(Logger.Level.FULL) .target(FileAPI.class, "http://localhost:8080");File file1 = new File("C:\\Users\\xxx\\Downloads\\test1.jpg");File file2 = new File("C:\\Users\\xxx\\Downloads\\test2.jpg");// 上传文件1：参数为文件对象fileAPI.upload(file1);// 上传文件2：参数为字节数组（注意：在服务端无法获取到文件名）byte[] bytes = FileUtils.readFileToByteArray(file1);fileAPI.upload(bytes);// 上传文件3：参数为FormData对象byte[] bytes = FileUtils.readFileToByteArray(file1);FormData formData = new FormData("image/jpg", "test1.jpg", bytes);String result = fileAPI.upload(formData);// 上传文件4：参数为POJO对象FileAPI.MyFile myFile = new FileAPI.MyFile();myFile.setPublic(true);myFile.setFile(file1);fileAPI.upload(myFile);// 上传文件：参数为多个文件fileAPI.upload(new File[]{file1, file2});fileAPI.upload(Arrays.asList(new File[]{file1, file2}));下载文件
定义接口：
public interface FileDownloadAPI { // 下载文件 @RequestLine("GET /test/download/file") Response download(@QueryMap Map<String, Object> queryMap);}调用接口：
// 下载文件时返回值为Response对象，不需要设置解码器FileAPI fileAPI = Feign.builder() .logger(new Slf4jLogger()) .logLevel(Logger.Level.FULL) .target(FileAPI.class, "http://localhost:8080");String fileName = "test.jpg";Map<String, Object> queryMap = new HashMap<>();queryMap.put("fileName", fileName);Response response = fileAPI.download(queryMap);if (response.status() == 200) { File downloadFile = new File("D:\\Downloads\\", fileName); FileUtils.copyInputStreamToFile(response.body().asInputStream(), downloadFile);}使用Spring Cloud Feign
在Spring框架中使用Feign实现文件上传时需要依赖feign-form和feign-form-spring，这2个模块已经在“Spring Cloud Feign”中自带了，只需要添加spring-cloud-starter-openfeign依赖即可。
<!-- 集成Spring和Feign，包含了模块feign-form和feign-form-spring --><dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> <version>3.0.2</version></dependency><!-- 文件操作工具类 --><dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.11.0</version></dependency>上传文件
定义接口及配置：
@FeignClient(value = "FileAPI", url = "http://localhost:8080", configuration = FileUploadAPI.FileUploadAPIConfiguration.class)public interface FileUploadAPI { @RequestMapping(value = "/test/upload/single", method = RequestMethod.POST, headers = "Content-Type=multipart/form-data") String upload(@RequestPart("file") MultipartFile file); @RequestMapping(value = "/test/upload/batch", method = RequestMethod.POST, headers = "Content-Type=multipart/form-data") String upload(@RequestPart("files") List<MultipartFile> files); class FileUploadAPIConfiguration { @Autowired private ObjectFactory<HttpMessageConverters> messageConverters; @Bean public Encoder feignEncoder () { return new SpringFormEncoder(new SpringEncoder(messageConverters)); } @Bean public Logger feignLogger() { return new Slf4jLogger(); } @Bean public Logger.Level feignLoggerLevel() { return Logger.Level.FULL; } }}调用接口：
// 上传单个文件File file = new File("C:\\Users\\xxx\\Downloads\\test1.jpg");FileInputStream fis = new FileInputStream(file);MockMultipartFile mockMultipartFile = new MockMultipartFile("file", file.getName(), "image/jpg", fis);this.fileUploadAPI.upload(mockMultipartFile);fis.close();// 上传多个文件File file1 = new File("C:\\Users\\xxx\\Downloads\\test1.jpg");File file2 = new File("C:\\Users\\xxx\\Downloads\\test2.jpg");FileInputStream fis1 = new FileInputStream(file1);FileInputStream fis2 = new FileInputStream(file2);MockMultipartFile f1 = new MockMultipartFile("files", file1.getName(), "image/jpg", fis1);MockMultipartFile f2 = new MockMultipartFile("files", file2.getName(), "image/jpg", fis2);this.fileUploadAPI.upload(Arrays.asList(new MockMultipartFile[]{f1, f2}));fis1.close();fis2.close();下载文件
定义接口：
@FeignClient(value = "FileDownloadAPI", url = "http://localhost:8080", configuration = FileDownloadAPI.FileDownloadAPIConfiguration.class)public interface FileDownloadAPI { @RequestMapping(value = "/test/download/file", method = RequestMethod.GET) Response download(@RequestParam("fileName") String fileName); // 下载文件时返回值为Response对象，不需要设置解码器 class FileDownloadAPIConfiguration { @Bean public Logger feignLogger() { return new Slf4jLogger(); } @Bean public Logger.Level feignLoggerLevel() { return Logger.Level.FULL; } }}调用接口：
String fileName = "test.jpg";Response response = this.fileDownloadAPI.download(fileName);File destFile = new File("D:\\Downloads\\", fileName);// 使用org.apache.commons.io.FileUtils工具类将输入流中的内容转存到文件FileUtils.copyInputStreamToFile(response.body().asInputStream(), destFile);以上就是关于“怎么用Spring Cloud Feign实现文件上传下载”这篇文章的内容，相信大家都有了一定的了解，希望小编分享的内容对大家有帮助，若想了解更多相关的知识内容，请关注编程网行业资讯频道。
