/*
* Copyright 2002-2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.client;
import java.io.IOException;
import java.lang.reflect.Type;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.xml.transform.Source;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.http.client.ClientHttpRequest;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.http.client.support.InterceptingHttpAccessor;
import org.springframework.http.converter.ByteArrayHttpMessageConverter;
import org.springframework.http.converter.GenericHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.ResourceHttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.feed.AtomFeedHttpMessageConverter;
import org.springframework.http.converter.feed.RssChannelHttpMessageConverter;
import org.springframework.http.converter.json.GsonHttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
import org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter;
import org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter;
import org.springframework.http.converter.xml.SourceHttpMessageConverter;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.web.util.UriTemplate;
/**
* <strong>Spring's central class for synchronous client-side HTTP access.</strong>
* It simplifies communication with HTTP servers, and enforces RESTful principles.
* It handles HTTP connections, leaving application code to provide URLs
* (with possible template variables) and extract results.
*
* <p>The main entry points of this template are the methods named after the six main HTTP methods:
* <table>
* <tr><th>HTTP method</th><th>RestTemplate methods</th></tr>
* <tr><td>DELETE</td><td>{@link #delete}</td></tr>
* <tr><td>GET</td><td>{@link #getForObject}</td></tr>
* <tr><td></td><td>{@link #getForEntity}</td></tr>
* <tr><td>HEAD</td><td>{@link #headForHeaders}</td></tr>
* <tr><td>OPTIONS</td><td>{@link #optionsForAllow}</td></tr>
* <tr><td>POST</td><td>{@link #postForLocation}</td></tr>
* <tr><td></td><td>{@link #postForObject}</td></tr>
* <tr><td>PUT</td><td>{@link #put}</td></tr>
* <tr><td>any</td><td>{@link #exchange}</td></tr>
* <tr><td></td><td>{@link #execute}</td></tr> </table>
*
* <p>In addition the {@code exchange} and {@code execute} methods are generalized versions of
* the above methods and can be used to support additional, less frequent combinations (e.g.
* HTTP PATCH, HTTP PUT with response body, etc.). Note however that the underlying HTTP
* library used must also support the desired combination.
*
* <p>For each HTTP method there are 3 variants -- two accept a URI template string
* and URI variables (array or map) while a third accepts a {@link URI}.
* Note that for URI templates it is assumed encoding is necessary, e.g.
* {@code restTemplate.getForObject("http://example.com/hotel list")} becomes
* {@code "http://example.com/hotel%20list"}. This also means if the URI template
* or URI variables are already encoded, double encoding will occur, e.g.
* {@code http://example.com/hotel%20list} becomes
* {@code http://example.com/hotel%2520list}). To avoid that use a {@code URI} method
* variant to provide (or re-use) a previously encoded URI. To prepare such an URI
* with full control over encoding, consider using
* {@link org.springframework.web.util.UriComponentsBuilder}.
*
* <p>Internally the template uses {@link HttpMessageConverter} instances to
* convert HTTP messages to and from POJOs. Converters for the main mime types
* are registered by default but you can also register additional converters
* via {@link #setMessageConverters}.
*
* <p>This template uses a
* {@link org.springframework.http.client.SimpleClientHttpRequestFactory} and a
* {@link DefaultResponseErrorHandler} as default strategies for creating HTTP
* connections or handling HTTP errors, respectively. These defaults can be overridden
* through {@link #setRequestFactory} and {@link #setErrorHandler} respectively.
*
* @author Arjen Poutsma
* @author Brian Clozel
* @author Roy Clarkson
* @since 3.0
* @see HttpMessageConverter
* @see RequestCallback
* @see ResponseExtractor
* @see ResponseErrorHandler
* @see AsyncRestTemplate
*/
public class RestTemplate extends InterceptingHttpAccessor implements RestOperations {
private static boolean romePresent =
ClassUtils.isPresent("com.rometools.rome.feed.WireFeed", RestTemplate.class.getClassLoader());
private static final boolean jaxb2Present =
ClassUtils.isPresent("javax.xml.bind.Binder", RestTemplate.class.getClassLoader());
private static final boolean jackson2Present =
ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", RestTemplate.class.getClassLoader()) &&
ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", RestTemplate.class.getClassLoader());
private static final boolean jackson2XmlPresent =
ClassUtils.isPresent("com.fasterxml.jackson.dataformat.xml.XmlMapper", RestTemplate.class.getClassLoader());
private static final boolean gsonPresent =
ClassUtils.isPresent("com.google.gson.Gson", RestTemplate.class.getClassLoader());
private final List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
private ResponseErrorHandler errorHandler = new DefaultResponseErrorHandler();
private final ResponseExtractor<HttpHeaders> headersExtractor = new HeadersExtractor();
/**
* Create a new instance of the {@link RestTemplate} using default settings.
* Default {@link HttpMessageConverter}s are initialized.
*/
public RestTemplate() {
this.messageConverters.add(new ByteArrayHttpMessageConverter());
this.messageConverters.add(new StringHttpMessageConverter());
this.messageConverters.add(new ResourceHttpMessageConverter());
this.messageConverters.add(new SourceHttpMessageConverter<Source>());
this.messageConverters.add(new AllEncompassingFormHttpMessageConverter());
if (romePresent) {
this.messageConverters.add(new AtomFeedHttpMessageConverter());
this.messageConverters.add(new RssChannelHttpMessageConverter());
}
if (jackson2XmlPresent) {
messageConverters.add(new MappingJackson2XmlHttpMessageConverter());
}
else if (jaxb2Present) {
this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
}
if (jackson2Present) {
this.messageConverters.add(new MappingJackson2HttpMessageConverter());
}
else if (gsonPresent) {
this.messageConverters.add(new GsonHttpMessageConverter());
}
}
/**
* Create a new instance of the {@link RestTemplate} based on the given {@link ClientHttpRequestFactory}.
* @param requestFactory HTTP request factory to use
* @see org.springframework.http.client.SimpleClientHttpRequestFactory
* @see org.springframework.http.client.HttpComponentsClientHttpRequestFactory
*/
public RestTemplate(ClientHttpRequestFactory requestFactory) {
this();
setRequestFactory(requestFactory);
}
/**
* Create a new instance of the {@link RestTemplate} using the given list of
* {@link HttpMessageConverter} to use
* @param messageConverters the list of {@link HttpMessageConverter} to use
* @since 3.2.7
*/
public RestTemplate(List<HttpMessageConverter<?>> messageConverters) {
Assert.notEmpty(messageConverters, "'messageConverters' must not be empty");
this.messageConverters.addAll(messageConverters);
}
/**
* Set the message body converters to use.
* <p>These converters are used to convert from and to HTTP requests and responses.
*/
public void setMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
Assert.notEmpty(messageConverters, "'messageConverters' must not be empty");
// Take getMessageConverters() List as-is when passed in here
if (this.messageConverters != messageConverters) {
this.messageConverters.clear();
this.messageConverters.addAll(messageConverters);
}
}
/**
* Return the message body converters.
*/
public List<HttpMessageConverter<?>> getMessageConverters() {
return this.messageConverters;
}
/**
* Set the error handler.
* <p>By default, RestTemplate uses a {@link DefaultResponseErrorHandler}.
*/
public void setErrorHandler(ResponseErrorHandler errorHandler) {
Assert.notNull(errorHandler, "'errorHandler' must not be null");
this.errorHandler = errorHandler;
}
/**
* Return the error handler.
*/
public ResponseErrorHandler getErrorHandler() {
return this.errorHandler;
}
// GET
@Override
public <T> T getForObject(String url, Class<T> responseType, Object... urlVariables) throws RestClientException {
RequestCallback requestCallback = acceptHeaderRequestCallback(responseType);
HttpMessageConverterExtractor<T> responseExtractor =
new HttpMessageConverterExtractor<T>(responseType, getMessageConverters(), logger);
return execute(url, HttpMethod.GET, requestCallback, responseExtractor, urlVariables);
}
@Override
public <T> T getForObject(String url, Class<T> responseType, Map<String, ?> urlVariables) throws RestClientException {
RequestCallback requestCallback = acceptHeaderRequestCallback(responseType);
HttpMessageConverterExtractor<T> responseExtractor =
new HttpMessageConverterExtractor<T>(responseType, getMessageConverters(), logger);
return execute(url, HttpMethod.GET, requestCallback, responseExtractor, urlVariables);
}
@Override
public <T> T getForObject(URI url, Class<T> responseType) throws RestClientException {
RequestCallback requestCallback = acceptHeaderRequestCallback(responseType);
HttpMessageConverterExtractor<T> responseExtractor =
new HttpMessageConverterExtractor<T>(responseType, getMessageConverters(), logger);
return execute(url, HttpMethod.GET, requestCallback, responseExtractor);
}
@Override
public <T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Object... urlVariables)
throws RestClientException {
RequestCallback requestCallback = acceptHeaderRequestCallback(responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(url, HttpMethod.GET, requestCallback, responseExtractor, urlVariables);
}
@Override
public <T> ResponseEntity<T> getForEntity(String url, Class<T> responseType, Map<String, ?> urlVariables)
throws RestClientException {
RequestCallback requestCallback = acceptHeaderRequestCallback(responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(url, HttpMethod.GET, requestCallback, responseExtractor, urlVariables);
}
@Override
public <T> ResponseEntity<T> getForEntity(URI url, Class<T> responseType) throws RestClientException {
RequestCallback requestCallback = acceptHeaderRequestCallback(responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(url, HttpMethod.GET, requestCallback, responseExtractor);
}
// HEAD
@Override
public HttpHeaders headForHeaders(String url, Object... urlVariables) throws RestClientException {
return execute(url, HttpMethod.HEAD, null, headersExtractor(), urlVariables);
}
@Override
public HttpHeaders headForHeaders(String url, Map<String, ?> urlVariables) throws RestClientException {
return execute(url, HttpMethod.HEAD, null, headersExtractor(), urlVariables);
}
@Override
public HttpHeaders headForHeaders(URI url) throws RestClientException {
return execute(url, HttpMethod.HEAD, null, headersExtractor());
}
// POST
@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();
}
@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);
}
@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);
}
// PUT
@Override
public void put(String url, Object request, Object... urlVariables) throws RestClientException {
RequestCallback requestCallback = httpEntityCallback(request);
execute(url, HttpMethod.PUT, requestCallback, null, urlVariables);
}
@Override
public void put(String url, Object request, Map<String, ?> urlVariables) throws RestClientException {
RequestCallback requestCallback = httpEntityCallback(request);
execute(url, HttpMethod.PUT, requestCallback, null, urlVariables);
}
@Override
public void put(URI url, Object request) throws RestClientException {
RequestCallback requestCallback = httpEntityCallback(request);
execute(url, HttpMethod.PUT, requestCallback, null);
}
// DELETE
@Override
public void delete(String url, Object... urlVariables) throws RestClientException {
execute(url, HttpMethod.DELETE, null, null, urlVariables);
}
@Override
public void delete(String url, Map<String, ?> urlVariables) throws RestClientException {
execute(url, HttpMethod.DELETE, null, null, urlVariables);
}
@Override
public void delete(URI url) throws RestClientException {
execute(url, HttpMethod.DELETE, null, null);
}
// OPTIONS
@Override
public Set<HttpMethod> optionsForAllow(String url, Object... urlVariables) throws RestClientException {
ResponseExtractor<HttpHeaders> headersExtractor = headersExtractor();
HttpHeaders headers = execute(url, HttpMethod.OPTIONS, null, headersExtractor, urlVariables);
return headers.getAllow();
}
@Override
public Set<HttpMethod> optionsForAllow(String url, Map<String, ?> urlVariables) throws RestClientException {
ResponseExtractor<HttpHeaders> headersExtractor = headersExtractor();
HttpHeaders headers = execute(url, HttpMethod.OPTIONS, null, headersExtractor, urlVariables);
return headers.getAllow();
}
@Override
public Set<HttpMethod> optionsForAllow(URI url) throws RestClientException {
ResponseExtractor<HttpHeaders> headersExtractor = headersExtractor();
HttpHeaders headers = execute(url, HttpMethod.OPTIONS, null, headersExtractor);
return headers.getAllow();
}
// exchange
@Override
public <T> ResponseEntity<T> exchange(String url, HttpMethod method,
HttpEntity<?> requestEntity, Class<T> responseType, Object... uriVariables) throws RestClientException {
RequestCallback requestCallback = httpEntityCallback(requestEntity, responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(url, method, requestCallback, responseExtractor, uriVariables);
}
@Override
public <T> ResponseEntity<T> exchange(String url, HttpMethod method,
HttpEntity<?> requestEntity, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
RequestCallback requestCallback = httpEntityCallback(requestEntity, responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(url, method, requestCallback, responseExtractor, uriVariables);
}
@Override
public <T> ResponseEntity<T> exchange(URI url, HttpMethod method, HttpEntity<?> requestEntity,
Class<T> responseType) throws RestClientException {
RequestCallback requestCallback = httpEntityCallback(requestEntity, responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(url, method, requestCallback, responseExtractor);
}
@Override
public <T> ResponseEntity<T> exchange(String url, HttpMethod method, HttpEntity<?> requestEntity,
ParameterizedTypeReference<T> responseType, Object... uriVariables) throws RestClientException {
Type type = responseType.getType();
RequestCallback requestCallback = httpEntityCallback(requestEntity, type);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(type);
return execute(url, method, requestCallback, responseExtractor, uriVariables);
}
@Override
public <T> ResponseEntity<T> exchange(String url, HttpMethod method, HttpEntity<?> requestEntity,
ParameterizedTypeReference<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
Type type = responseType.getType();
RequestCallback requestCallback = httpEntityCallback(requestEntity, type);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(type);
return execute(url, method, requestCallback, responseExtractor, uriVariables);
}
@Override
public <T> ResponseEntity<T> exchange(URI url, HttpMethod method, HttpEntity<?> requestEntity,
ParameterizedTypeReference<T> responseType) throws RestClientException {
Type type = responseType.getType();
RequestCallback requestCallback = httpEntityCallback(requestEntity, type);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(type);
return execute(url, method, requestCallback, responseExtractor);
}
@Override
public <T> ResponseEntity<T> exchange(RequestEntity<?> requestEntity, Class<T> responseType)
throws RestClientException {
Assert.notNull(requestEntity, "'requestEntity' must not be null");
RequestCallback requestCallback = httpEntityCallback(requestEntity, responseType);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType);
return execute(requestEntity.getUrl(), requestEntity.getMethod(), requestCallback, responseExtractor);
}
@Override
public <T> ResponseEntity<T> exchange(RequestEntity<?> requestEntity, ParameterizedTypeReference<T> responseType)
throws RestClientException {
Assert.notNull(requestEntity, "'requestEntity' must not be null");
Type type = responseType.getType();
RequestCallback requestCallback = httpEntityCallback(requestEntity, type);
ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(type);
return execute(requestEntity.getUrl(), requestEntity.getMethod(), requestCallback, responseExtractor);
}
// general execution
@Override
public <T> T execute(String url, HttpMethod method, RequestCallback requestCallback,
ResponseExtractor<T> responseExtractor, Object... urlVariables) throws RestClientException {
URI expanded = new UriTemplate(url).expand(urlVariables);
return doExecute(expanded, method, requestCallback, responseExtractor);
}
@Override
public <T> T execute(String url, HttpMethod method, RequestCallback requestCallback,
ResponseExtractor<T> responseExtractor, Map<String, ?> urlVariables) throws RestClientException {
URI expanded = new UriTemplate(url).expand(urlVariables);
return doExecute(expanded, method, requestCallback, responseExtractor);
}
@Override
public <T> T execute(URI url, HttpMethod method, RequestCallback requestCallback,
ResponseExtractor<T> responseExtractor) throws RestClientException {
return doExecute(url, method, requestCallback, responseExtractor);
}
/**
* Execute the given method on the provided URI.
* <p>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}
*/
protected <T> T doExecute(URI url, HttpMethod method, RequestCallback requestCallback,
ResponseExtractor<T> 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();
if (!getErrorHandler().hasError(response)) {
logResponseStatus(method, url, response);
}
else {
handleResponseError(method, url, response);
}
if (responseExtractor != null) {
return responseExtractor.extractData(response);
}
else {
return null;
}
}
catch (IOException ex) {
throw new ResourceAccessException("I/O error on " + method.name() +
" request for \"" + url + "\":" + ex.getMessage(), ex);
}
finally {
if (response != null) {
response.close();
}
}
}
private void logResponseStatus(HttpMethod method, URI url, ClientHttpResponse response) {
if (logger.isDebugEnabled()) {
try {
logger.debug(method.name() + " request for \"" + url + "\" resulted in " +
response.getRawStatusCode() + " (" + response.getStatusText() + ")");
}
catch (IOException e) {
// ignore
}
}
}
private void handleResponseError(HttpMethod method, URI url, ClientHttpResponse response) throws IOException {
if (logger.isWarnEnabled()) {
try {
logger.warn(method.name() + " request for \"" + url + "\" resulted in " +
response.getRawStatusCode() + " (" + response.getStatusText() + "); invoking error handler");
}
catch (IOException e) {
// ignore
}
}
getErrorHandler().handleError(response);
}
/**
* Returns a request callback implementation that prepares the request {@code Accept}
* headers based on the given response type and configured
* {@linkplain #getMessageConverters() message converters}.
*/
protected <T> RequestCallback acceptHeaderRequestCallback(Class<T> responseType) {
return new AcceptHeaderRequestCallback(responseType);
}
/**
* Returns a request callback implementation that writes the given object to the
* request stream.
*/
protected <T> RequestCallback httpEntityCallback(Object requestBody) {
return new HttpEntityRequestCallback(requestBody);
}
/**
* Returns a request callback implementation that writes the given object to the
* request stream.
*/
protected <T> RequestCallback httpEntityCallback(Object requestBody, Type responseType) {
return new HttpEntityRequestCallback(requestBody, responseType);
}
/**
* Returns a response extractor for {@link ResponseEntity}.
*/
protected <T> ResponseExtractor<ResponseEntity<T>> responseEntityExtractor(Type responseType) {
return new ResponseEntityResponseExtractor<T>(responseType);
}
/**
* Returns a response extractor for {@link HttpHeaders}.
*/
protected ResponseExtractor<HttpHeaders> headersExtractor() {
return this.headersExtractor;
}
/**
* Request callback implementation that prepares the request's accept headers.
*/
private class AcceptHeaderRequestCallback implements RequestCallback {
private final Type responseType;
private AcceptHeaderRequestCallback(Type responseType) {
this.responseType = responseType;
}
@Override
public void doWithRequest(ClientHttpRequest request) throws IOException {
if (responseType != null) {
Class<?> responseClass = null;
if (responseType instanceof Class) {
responseClass = (Class<?>) responseType;
}
List<MediaType> allSupportedMediaTypes = new ArrayList<MediaType>();
for (HttpMessageConverter<?> converter : getMessageConverters()) {
if (responseClass != null) {
if (converter.canRead(responseClass, null)) {
allSupportedMediaTypes.addAll(getSupportedMediaTypes(converter));
}
}
else if (converter instanceof GenericHttpMessageConverter) {
GenericHttpMessageConverter<?> genericConverter = (GenericHttpMessageConverter<?>) converter;
if (genericConverter.canRead(responseType, null, null)) {
allSupportedMediaTypes.addAll(getSupportedMediaTypes(converter));
}
}
}
if (!allSupportedMediaTypes.isEmpty()) {
MediaType.sortBySpecificity(allSupportedMediaTypes);
if (logger.isDebugEnabled()) {
logger.debug("Setting request Accept header to " +
allSupportedMediaTypes);
}
request.getHeaders().setAccept(allSupportedMediaTypes);
}
}
}
private List<MediaType> getSupportedMediaTypes(HttpMessageConverter<?> messageConverter) {
List<MediaType> supportedMediaTypes = messageConverter.getSupportedMediaTypes();
List<MediaType> result = new ArrayList<MediaType>(supportedMediaTypes.size());
for (MediaType supportedMediaType : supportedMediaTypes) {
if (supportedMediaType.getCharSet() != null) {
supportedMediaType =
new MediaType(supportedMediaType.getType(), supportedMediaType.getSubtype());
}
result.add(supportedMediaType);
}
return result;
}
}
/**
* Request callback implementation that writes the given object to the request stream.
*/
private class HttpEntityRequestCallback extends AcceptHeaderRequestCallback {
private final HttpEntity<?> requestEntity;
private HttpEntityRequestCallback(Object requestBody) {
this(requestBody, null);
}
private HttpEntityRequestCallback(Object requestBody, Type responseType) {
super(responseType);
if (requestBody instanceof HttpEntity) {
this.requestEntity = (HttpEntity<?>) requestBody;
}
else if (requestBody != null) {
this.requestEntity = new HttpEntity<Object>(requestBody);
}
else {
this.requestEntity = HttpEntity.EMPTY;
}
}
@Override
@SuppressWarnings("unchecked")
public void doWithRequest(ClientHttpRequest httpRequest) throws IOException {
super.doWithRequest(httpRequest);
if (!requestEntity.hasBody()) {
HttpHeaders httpHeaders = httpRequest.getHeaders();
HttpHeaders requestHeaders = requestEntity.getHeaders();
if (!requestHeaders.isEmpty()) {
httpHeaders.putAll(requestHeaders);
}
if (httpHeaders.getContentLength() == -1) {
httpHeaders.setContentLength(0L);
}
}
else {
Object requestBody = requestEntity.getBody();
Class<?> requestType = requestBody.getClass();
HttpHeaders requestHeaders = requestEntity.getHeaders();
MediaType requestContentType = requestHeaders.getContentType();
for (HttpMessageConverter<?> messageConverter : getMessageConverters()) {
if (messageConverter.canWrite(requestType, requestContentType)) {
if (!requestHeaders.isEmpty()) {
httpRequest.getHeaders().putAll(requestHeaders);
}
if (logger.isDebugEnabled()) {
if (requestContentType != null) {
logger.debug("Writing [" + requestBody + "] as \"" + requestContentType +
"\" using [" + messageConverter + "]");
}
else {
logger.debug("Writing [" + requestBody + "] using [" + messageConverter + "]");
}
}
((HttpMessageConverter<Object>) messageConverter).write(
requestBody, requestContentType, httpRequest);
return;
}
}
String message = "Could not write request: no suitable HttpMessageConverter found for request type [" +
requestType.getName() + "]";
if (requestContentType != null) {
message += " and content type [" + requestContentType + "]";
}
throw new RestClientException(message);
}
}
}
/**
* Response extractor for {@link HttpEntity}.
*/
private class ResponseEntityResponseExtractor<T> implements ResponseExtractor<ResponseEntity<T>> {
private final HttpMessageConverterExtractor<T> delegate;
public ResponseEntityResponseExtractor(Type responseType) {
if (responseType != null && !Void.class.equals(responseType)) {
this.delegate = new HttpMessageConverterExtractor<T>(responseType, getMessageConverters(), logger);
}
else {
this.delegate = null;
}
}
@Override
public ResponseEntity<T> extractData(ClientHttpResponse response) throws IOException {
if (this.delegate != null) {
T body = this.delegate.extractData(response);
return new ResponseEntity<T>(body, response.getHeaders(), response.getStatusCode());
}
else {
return new ResponseEntity<T>(response.getHeaders(), response.getStatusCode());
}
}
}
/**
* Response extractor that extracts the response {@link HttpHeaders}.
*/
private static class HeadersExtractor implements ResponseExtractor<HttpHeaders> {
@Override
public HttpHeaders extractData(ClientHttpResponse response) throws IOException {
return response.getHeaders();
}
}
}