RestTemplate Post请求

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RestTemplate Post请求

对Post请求可以通过如下三个方法进行调用

第一种：postForEntity方法

与GET请求的getForEntity类似，

user = new User("didi", 30);
ResponseEntity<String> responseEntity = restTemplate.postForEntity("http://HELLO-SERVICE/hello3", user, String.class);

postForEntity也有三个不同的重载方法

@Override
public <T> ResponseEntity<T> postForEntity(String url, Object request, Class<T> responseType, Object... uriVariables)
      throws RestClientException {

   RequestCallback requestCallback = httpEntityCallback(request, responseType);
   ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
   return execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables);
}

@Override
public <T> ResponseEntity<T> postForEntity(String url, Object request, Class<T> responseType, Map<String, ?> uriVariables)
      throws RestClientException {

   RequestCallback requestCallback = httpEntityCallback(request, responseType);
   ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
   return execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables);
}

@Override
public <T> ResponseEntity<T> postForEntity(URI url, Object request, Class<T> responseType) throws RestClientException {
   RequestCallback requestCallback = httpEntityCallback(request, responseType);
   ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
   return execute(url, HttpMethod.POST, requestCallback, responseExtractor);
}

这些方法中的参数用法和getForEntity一致，其中request参数可以是一个普通对象，也可以是HttpEntity对象。如果是普通对象，RestTemplate会将请求对象转换成HttpEntity对象来处理，request内容视为body；如果是HttpEntity对象，当作完整的HTTP请求对象处理，不仅包含body内容，也包含header内容。

第二种：postForObject方法

跟getForObject方法类似，作用是简化postForEntity后续处理，直接将请求响应的body内容包装成对象返回使用。

@Override
public <T> T postForObject(String url, Object request, Class<T> responseType, Object... uriVariables)
      throws RestClientException {

   RequestCallback requestCallback = httpEntityCallback(request, responseType);
   HttpMessageConverterExtractor<T> responseExtractor =
         new HttpMessageConverterExtractor<T>(responseType, getMessageConverters(), logger);
   return execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables);
}

@Override
public <T> T postForObject(String url, Object request, Class<T> responseType, Map<String, ?> uriVariables)
      throws RestClientException {

   RequestCallback requestCallback = httpEntityCallback(request, responseType);
   HttpMessageConverterExtractor<T> responseExtractor =
         new HttpMessageConverterExtractor<T>(responseType, getMessageConverters(), logger);
   return execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables);
}

@Override
public <T> T postForObject(URI url, Object request, Class<T> responseType) throws RestClientException {
   RequestCallback requestCallback = httpEntityCallback(request, responseType);
   HttpMessageConverterExtractor<T> responseExtractor =
         new HttpMessageConverterExtractor<T>(responseType, getMessageConverters());
   return execute(url, HttpMethod.POST, requestCallback, responseExtractor);
}

第三种：postForLocation方法

返回新的资源URI

@Override
public URI postForLocation(String url, Object request, Object... urlVariables) throws RestClientException {
   RequestCallback requestCallback = httpEntityCallback(request);
   HttpHeaders headers = execute(url, HttpMethod.POST, requestCallback, headersExtractor(), urlVariables);
   return headers.getLocation();
}

@Override
public URI postForLocation(String url, Object request, Map<String, ?> urlVariables) throws RestClientException {
   RequestCallback requestCallback = httpEntityCallback(request);
   HttpHeaders headers = execute(url, HttpMethod.POST, requestCallback, headersExtractor(), urlVariables);
   return headers.getLocation();
}

@Override
public URI postForLocation(URI url, Object request) throws RestClientException {
   RequestCallback requestCallback = httpEntityCallback(request);
   HttpHeaders headers = execute(url, HttpMethod.POST, requestCallback, headersExtractor());
   return headers.getLocation();
}