使用Feign实现微服务间文件下载

在使用feign做服务间调用的时候,当下载大的文件会出现堆栈溢出的情况。另外，文件管理服务（服务提供者）文件下载接口无返回值，是通过httpservletrespoonse传输的流数据来响应，那么服务消费者该如何接受下载的数据呢？

一. 示例介绍

我们调用feign_upload_second的下载文件接口下载文件，feign_upload_second内部使用feign调用feign_upload_first实现文件下载。

二、feign_upload_first服务提供者

服务提供者下载文件接口

@requestmapping(value = "/downloadfile",method = requestmethod.get,consumes = mediatype.application_json_utf8_value)
 public void downloadfile(httpservletresponse response){
  string filepath = "d://1.txt";
  file file = new file(filepath);
  inputstream in = null;
  if(file.exists()){
  try {
   outputstream out = response.getoutputstream();
   in = new fileinputstream(file);
   byte buffer[] = new byte[1024];
   int length = 0;
   while ((length = in.read(buffer)) >= 0){
   out.write(buffer,0,length);
   }
  } catch (ioexception e) {
   e.printstacktrace();
  } finally {
   if(in != null){
   try {
    in.close();
   } catch (ioexception e) {
    e.printstacktrace();
   }
   }
  }
  }
 }

三、feign_upload_second服务消费者

服务提供者远程调用接口

@requestmapping(value = "/downloadfile",method = requestmethod.get,consumes = mediatype.application_json_utf8_value)
 response downloadfile();

用feign.response来接收

服务提供者下载文件接口

@requestmapping(value = "/download",method = requestmethod.get)
 public responseentity<byte[]> downfile(){
 responseentity<byte[]> result=null ;
 inputstream inputstream = null;
 try {
  // feign文件下载
  response response = uploadservice.downloadfile();
  response.body body = response.body();
  inputstream = body.asinputstream();
  byte[] b = new byte[inputstream.available()];
  inputstream.read(b);
  httpheaders heads = new httpheaders();
  heads.add(httpheaders.content_disposition, "attachment;filename=123.txt");
  heads.add(httpheaders.content_type,mediatype.application_json_value);

  result = new responseentity <byte[]>(b,heads, httpstatus.ok);
 } catch (ioexception e) {
  e.printstacktrace();
 } finally {
  if(inputstream != null){
  try {
   inputstream.close();
  } catch (ioexception e) {
   e.printstacktrace();
  }
  }
 }
 return result;
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。