Remember that resttemplate.getforentity failed to carry headers once, resttemplate exchange

Remember to use it once restTemplate.getForEntity carry header Solutions to failed requests . Because one day I suddenly received a demand , You need to access an interface , And change the interface , You must carry the current user's cookie. Because the system basically uses restTemplate.postForEntity, carry header No problem , So I changed it directly get, So it was a tragedy .

restTemplate.postForEntity The code is as follows

//  obtain headerHttpHeaders headers = new HttpHeaders();HttpServletRequest request = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getRequest();headers.add("Cookie", request.getHeader("Cookie"));//  send out Map<String, Object> param = new HashMap<>();param.put("param", "param");HttpEntity<String> entity = new HttpEntity<>(JSON.toJSONString(param), headers);ResponseEntity<String> responseEntity = restTemplate.postForEntity(url, entity, String.class);String body = responseEntity.getBody();

None of this is a problem , Requests are normal

So I put restTemplate.postForEntity Change it to restTemplate.getForEntity. An error message appears

After careful comparison and postForEntity The difference between .

I changed it to . Confident enough , Then it's a long way to find out why .

ResponseEntity<String> responseEntity = restTemplate.getForEntity("", String.class, entity);

The final conclusion ,getforEntity No settings header Methods , Although I changed the order, I didn't report the wrong , But after the exchange , It's not setting at all header Value . There is no such thing as setHeader

restTemplate.exchage

Belongs to template method , Can directly set the request mode , Set request header . The key codes are as follows ：

ResponseEntity<String> exchange = restTemplate.exchange(url,        HttpMethod.GET, entity, String.class, new Object[0]);

Using this method, you can get The request carries the request header .

other ： I also found some usage on the Internet getForEntity, send out header The way to , Similar use filter, More trouble , I'm not going to expand it . Interested in their own Baidu .