背景：服务端提供了一个下载服务，用FeignClient调用该服务时发生错误。
错误信息为：getOutputStream() has already been called for this response
此错误原因是response已经被调用
解决方法：需要用到Feign提供的Request来做一次中继操作
代码：
服务端：
/**
* 下载文件
* @param filePath 文件路径
* @param downloadName 下载后的文件名(1.txt)
* @param response
*/
public static void downloadFile(String filePath, String downloadName, HttpServletResponse response) throws UnsupportedEncodingException {
response.reset();
response.setHeader("Content-Disposition", "attachment;filename="+ new String((downloadName).getBytes(), "iso-8859-1"));
response.setContentType("text/plain;charset=utf-8");
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();
}
}
}
}
}
@GetMapping("download")
public void downloadYjya(HttpServletResponse response) throws IOException {
downloadFile(?, ?, response);
}客户端：
public interface RtYjClient {
@GetMapping("download")
Response downloadYjya();
} @GetMapping("download")
public void downloadYjya(HttpServletResponse servletResponse) throws IOException {
Response response = rtYjClient.downloadYjya();
Response.Body body = response.body();
for (Object key : response.headers().keySet()) {
List<String> kList = (List<String>) response.headers().get(key);
for (String val : kList) {
servletResponse.setHeader(key.toString(), val);
}
}
InputStream inputStream = null;
OutputStream outputStream = null;
try {
inputStream = body.asInputStream();
outputStream = servletResponse.getOutputStream();
byte[] b = new byte[inputStream.available()];
inputStream.read(b);
outputStream.write(b);
outputStream.flush();
} catch (IOException e) {
System.out.println("失败了");
}finally {
inputStream.close();
outputStream.close();
}
}参考文章：
1，https://www.jb51.net/article/160275.htm
2，FeignClient 跨服务上传文件、导出Excel_赵丙双的博客-CSDN博客_feign 导出excel
3，Feign跨服务下载文件； getOutputStream() has already been called for this response_在你之后的博客-CSDN博客
