Java tutorial
/* * 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 {@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 {@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; }