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脚本之家。
