/*
 * Copyright 2002-2018 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
 *
 *      https://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 org.springframework.http.client.ClientHttpResponse;
import org.springframework.lang.Nullable;

Generic callback interface used by RestTemplate's retrieval methods. Implementations of this interface perform the actual work of extracting data from a ClientHttpResponse, but don't need to worry about exception handling or closing resources. 
Used internally by the RestTemplate, but also useful for application code. There is one available factory method, see RestTemplate.responseEntityExtractor(Type). 
Author:
Arjen Poutsma
Type parameters:
<T> – the data type
See Also:
RestTemplate.execute
Since:
3.0/**
 * Generic callback interface used by {@link RestTemplate}'s retrieval methods.
 * Implementations of this interface perform the actual work of extracting data
 * from a {@link ClientHttpResponse}, but don't need to worry about exception
 * handling or closing resources.
 *
 * <p>Used internally by the {@link RestTemplate}, but also useful for
 * application code. There is one available factory method, see
 * {@link RestTemplate#responseEntityExtractor(Type)}.
 *
 * @author Arjen Poutsma
 * @since 3.0
 * @param <T> the data type
 * @see RestTemplate#execute
 */
@FunctionalInterface
public interface ResponseExtractor<T> {

	
Extract data from the given ClientHttpResponse and return it. 
Params:
response – the HTTP response
Throws:
IOException – in case of I/O errors
Returns:
the extracted data/**
	 * Extract data from the given {@code ClientHttpResponse} and return it.
	 * @param response the HTTP response
	 * @return the extracted data
	 * @throws IOException in case of I/O errors
	 */
	@Nullable
	T extractData(ClientHttpResponse response) throws IOException;

}