SpringBoot使用RestTemplate消费REST服务的几个问题记录

public  T getForObject(String url, Class responseType, Object... uriVariables) 

public  ResponseEntity getForEntity(String url, Class responseType, Object... uriVariables)

public  T postForObject(String url, @Nullable Object request, Class responseType,Object... uriVariables)

public  ResponseEntity postForEntity(String url, @Nullable Object request,Class responseType, Object... uriVariables)

public void delete(String url, Object... uriVariables)

public void delete(URI url)

 /**
  * Execute the given method on the provided URI.
  * 
The {@link ClientHttpRequest} is processed using the {@link RequestCallback};
  * the response with the {@link ResponseExtractor}.
  * @param url the fully-expanded URL to connect to
  * @param method the HTTP method to execute (GET, POST, etc.)
  * @param requestCallback object that prepares the request (can be {@code null})
  * @param responseExtractor object that extracts the return value from the response (can be {@code null})
  * @return an arbitrary object, as returned by the {@link ResponseExtractor}
  */
 @Nullable
 protected  T doExecute(URI url, @Nullable HttpMethod method, @Nullable RequestCallback requestCallback,
   @Nullable ResponseExtractor responseExtractor) throws RestClientException {

  Assert.notNull(url, "'url' must not be null");
  Assert.notNull(method, "'method' must not be null");
  ClientHttpResponse response = null;
  try {
   ClientHttpRequest request = createRequest(url, method);
   if (requestCallback != null) {
    requestCallback.doWithRequest(request);
   }
   response = request.execute();
   handleResponse(url, method, response);
   if (responseExtractor != null) {
    return responseExtractor.extractData(response);
   }
   else {
    return null;
   }
  }
  catch (IOException ex) {
   String resource = url.toString();
   String query = url.getRawQuery();
   resource = (query != null ? resource.substring(0, resource.indexOf('?')) : resource);
   throw new ResourceAccessException("I/O error on " + method.name() +
     " request for \"" + resource + "\": " + ex.getMessage(), ex);
  }
  finally {
   if (response != null) {
    response.close();
   }
  }
 }

package com.power.demo.restclient;

import com.power.demo.common.AppConst;
import com.power.demo.restclient.clientrequest.ClientGetGoodsByGoodsIdRequest;
import com.power.demo.restclient.clientresponse.ClientGetGoodsByGoodsIdResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;

/**
 * 商品REST接口客户端 （demo测试用）
 **/
@Component
public class GoodsServiceClient {

 //服务消费者调用的接口URL 形如：http://localhost:9090
 @Value("${spring.power.serviceurl}")
 private String _serviceUrl;

 @Autowired
 private RestTemplate restTemplate;

 public ClientGetGoodsByGoodsIdResponse getGoodsByGoodsId(ClientGetGoodsByGoodsIdRequest request) {
  String svcUrl = getGoodsSvcUrl() + "/getinfobyid";

  ClientGetGoodsByGoodsIdResponse response = null;

  try {
   response = restTemplate.postForObject(svcUrl, request, ClientGetGoodsByGoodsIdResponse.class);
  } catch (Exception e) {
   e.printStackTrace();
   response = new ClientGetGoodsByGoodsIdResponse();
   response.setCode(AppConst.FAIL);
   response.setMessage(e.toString());
  }

  return response;
 }

 private String getGoodsSvcUrl() {

  String url = "";

  if (_serviceUrl == null) {
   _serviceUrl = "";
  }
  if (_serviceUrl.length() == 0) {
   return url;
  }

  if (_serviceUrl.substring(_serviceUrl.length() - 1, _serviceUrl.length()) == "/") {
   url = String.format("%sapi/v1/goods", _serviceUrl);
  } else {
   url = String.format("%s/api/v1/goods", _serviceUrl);
  }

  return url;
 }
}

  @Override
  @SuppressWarnings("unchecked")
  public void doWithRequest(ClientHttpRequest httpRequest) throws IOException {
   super.doWithRequest(httpRequest);
   Object requestBody = this.requestEntity.getBody();
   if (requestBody == null) {
    HttpHeaders httpHeaders = httpRequest.getHeaders();
    HttpHeaders requestHeaders = this.requestEntity.getHeaders();
    if (!requestHeaders.isEmpty()) {
     for (Map.Entry> entry : requestHeaders.entrySet()) {
      httpHeaders.put(entry.getKey(), new LinkedList<>(entry.getValue()));
     }
    }
    if (httpHeaders.getContentLength() < 0) {
     httpHeaders.setContentLength(0L);
    }
   }
   else {
    Class<?> requestBodyClass = requestBody.getClass();
    Type requestBodyType = (this.requestEntity instanceof RequestEntity ?
      ((RequestEntity<?>)this.requestEntity).getType() : requestBodyClass);
    HttpHeaders httpHeaders = httpRequest.getHeaders();
    HttpHeaders requestHeaders = this.requestEntity.getHeaders();
    MediaType requestContentType = requestHeaders.getContentType();
    for (HttpMessageConverter<?> messageConverter : getMessageConverters()) {
     if (messageConverter instanceof GenericHttpMessageConverter) {
      GenericHttpMessageConverter