Spring Cloud Feign文件传输的示例代码

2021-05-07 11:07cipher Java教程

微服务中通常使用 Feign 作为服务消费者，那么如何使用 Feign 接口传输文件呢？这篇文章主要介绍了Spring Cloud Feign文件传输的示例代码，感兴趣的小伙伴们可以参考一下

一、配置文件解析器

服务提供者和消费者都需要配置文件解析器，这里使用 commons-fileupload 替换原有的解析器：

依赖：

									<dependency>

									  <groupid>commons-fileupload</groupid>

									  <artifactid>commons-fileupload</artifactid>

									  <version>1.3.1</version>

									</dependency>

注入 bean ：

									@bean(name = "multipartresolver")

									public multipartresolver mutipartresolver(){

									  commonsmultipartresolver com = new commonsmultipartresolver();

									  com.setdefaultencoding("utf-8");

									  return com;

									}

程序入口中剔除原有的解析器：

1	`@springbootapplication(exclude = {multipartautoconfiguration.class})`

二、服务提供者，即接收文件一方的配置

controller 的写法：

									@responsebody

									@requestmapping(value = "/upload", method = {requestmethod.post},

									        produces = {mediatype.application_json_utf8_value},

									        consumes = mediatype.multipart_form_data_value)

									public result<string> uploadfile(@requestpart("file")multipartfile file,

									@requestparam("id")long id){

									  string filename = file.getoriginalfilename();

									  string extend = fileoperateutil.suffix(filename);

									  fileoperateutil.copy("e:\\" + filename, file);

									  return resultbuilder.success("ok");

									}

@requestpart 指定文件，后面的 @requestparam 是额外参数，注意额外参数不能超过url长度限制。

三、服务消费者配置

依赖：

									<dependency>

									  <groupid>io.github.openfeign.form</groupid>

									  <artifactid>feign-form-spring</artifactid>

									  <version>3.2.2</version>

									</dependency>

									<dependency>

									  <groupid>io.github.openfeign.form</groupid>

									  <artifactid>feign-form</artifactid>

									  <version>3.2.2</version>

									</dependency>

文件编码配置：

									import feign.codec.encoder;

									import feign.form.spring.springformencoder;

									import org.springframework.beans.factory.objectfactory;

									import org.springframework.beans.factory.annotation.autowired;

									import org.springframework.boot.autoconfigure.web.httpmessageconverters;

									import org.springframework.cloud.netflix.feign.support.springencoder;

									import org.springframework.context.annotation.bean;

									import org.springframework.context.annotation.configuration;

									@configuration

									public class multipartsupportconfig{

									  @autowired

									  private objectfactory<httpmessageconverters> messageconverters;

									  @bean

									  public encoder feignformencoder(){

									    return new springformencoder(new springencoder(messageconverters));

									  }

									}

feign 接口定义：

									@feignclient(name = "test-upload")

									public interface uploadservice{

									  @responsebody

									  @requestmapping(value = "/upload", method = {requestmethod.post},

									      produces = {mediatype.application_json_utf8_value},

									      consumes = mediatype.multipart_form_data_value)

									  result<string>uploadfile(@requestpart("file")multipartfile file,

									@requestparam("id")long id);

									}

与普通 feign 接口写法差不多，注意方法注解和参数与服务提供者的 controller 一样。

controller 的写法， controller 中接收前端传过来的文件信息和额外参数，然后通过 feign 接口传输到远端：

									// 注入 feign 接口

									@autowired

									private uploadservice uploadservice;

									@requestmapping(value = "/upload", method = requestmethod.post, produces = "application/json; charset=utf-8")

									@responsebody

									public result<string> testupload(httpservletrequest request, long id){

									  result<string> result = null;

									  multiparthttpservletrequest mrequest = (multiparthttpservletrequest) request;

									  map<string, multipartfile> filemap = mrequest.getfilemap();

									  for (multipartfile mfile : filemap.values()) {

									    string filename = mfile.getoriginalfilename();

									    result = uploadservice.uploadfile(mfile, id);

									  }

									  return result;

									}