org.springframework.cloud.zookeeper.discovery.dependency.DependencyRestTemplateAutoConfiguration.java Source code

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Here is the source code for org.springframework.cloud.zookeeper.discovery.dependency.DependencyRestTemplateAutoConfiguration.java

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/*
 * Copyright 2013-2015 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.cloud.zookeeper.discovery.dependency;

import java.io.IOException;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import javax.annotation.PostConstruct;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.zookeeper.discovery.ConditionalOnRibbonZookeeper;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.web.client.RestTemplate;

import com.google.common.base.Function;
import com.google.common.collect.Maps;

/**
 *
 * Customizes RestTemplate to support passing of params from dependency
 *
 * @author Marcin Grzejszczak, 4financeIT
 */
@AutoConfigureAfter(DependencyRibbonAutoConfiguration.class)
@ConditionalOnRibbonZookeeper
@Configuration
@ConditionalOnDependenciesPassed
@ConditionalOnProperty(value = "spring.cloud.zookeeper.dependencies.resttemplate.enabled", matchIfMissing = true)
public class DependencyRestTemplateAutoConfiguration {

    @Autowired
    @LoadBalanced
    RestTemplate restTemplate;
    @Autowired
    ZookeeperDependencies zookeeperDependencies;

    @PostConstruct
    void customizeRestTemplate() {
        this.restTemplate.getInterceptors().add(new ClientHttpRequestInterceptor() {
            @Override
            public ClientHttpResponse intercept(HttpRequest request, byte[] body,
                    ClientHttpRequestExecution execution) throws IOException {
                String clientName = request.getURI().getHost();
                ZookeeperDependency dependencyForAlias = DependencyRestTemplateAutoConfiguration.this.zookeeperDependencies
                        .getDependencyForAlias(clientName);
                HttpHeaders headers = getUpdatedHeadersIfPossible(request, dependencyForAlias);
                request.getHeaders().putAll(headers);
                return execution.execute(request, body);
            }

            private HttpHeaders getUpdatedHeadersIfPossible(HttpRequest request,
                    ZookeeperDependency dependencyForAlias) {
                HttpHeaders httpHeaders = new HttpHeaders();
                if (dependencyForAlias != null) {
                    Map<String, Collection<String>> updatedHeaders = dependencyForAlias
                            .getUpdatedHeaders(convertHeadersFromListToCollection(request.getHeaders()));
                    httpHeaders.putAll(convertHeadersFromCollectionToList(updatedHeaders));
                    return httpHeaders;
                }
                httpHeaders.putAll(request.getHeaders());
                return httpHeaders;
            }

            private Map<String, Collection<String>> convertHeadersFromListToCollection(HttpHeaders headers) {
                return Maps.transformValues(headers, new Function<List<String>, Collection<String>>() {
                    @Override
                    public Collection<String> apply(List<String> input) {
                        return input;
                    }
                });
            }

            private Map<String, List<String>> convertHeadersFromCollectionToList(
                    Map<String, Collection<String>> headers) {
                return Maps.transformValues(headers, new Function<Collection<String>, List<String>>() {
                    @Override
                    public List<String> apply(Collection<String> input) {
                        return (List<String>) input;
                    }
                });
            }
        });
    }

}