Java tutorial
/* * Copyright 2010-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. * A copy of the License is located at * * http://aws.amazon.com/apache2.0 * * or in the "license" file accompanying this file. This file 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 com.amazonaws.hal.client; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Map; import java.util.Set; import static com.amazonaws.hal.Link.KeyField; class HalLinkMap<T> implements Map<String, T> { //------------------------------------------------------------- // Variables - Private //------------------------------------------------------------- private Map<String, T> inner; private static Log log = LogFactory.getLog(HalLinkMap.class); //------------------------------------------------------------- // Constructors //------------------------------------------------------------- HalLinkMap(HalResource halResource, String relation, KeyField keyField, Class<T> type, HalClient halClient) { Map<String, T> resources = new HashMap<>(); HalLink halLink; int index = 0; String indexedRelation = indexedRelation(relation, index); while ((halLink = halResource.getLink(indexedRelation)) != null) { String key = keyField == KeyField.Title ? halLink.getTitle() : halLink.getName(); if (key == null) { log.warn("No key value for mapped link. Using '" + indexedRelation + "' instead"); resources.put(indexedRelation, halClient.getResource(halResource, type, halLink.getHref(), true)); } else { resources.put(key, halClient.getResource(halResource, type, halLink.getHref(), true)); } indexedRelation = indexedRelation(relation, index++); } // Handle case when there was a single item and therefore was not mapped to an array if (resources.size() == 0 && (halLink = halResource.getLink(relation)) != null) { String key = keyField == KeyField.Title ? halLink.getTitle() : halLink.getName(); if (key == null) { log.warn("No key value for mapped link. Using '" + relation + "' instead"); resources.put(relation, halClient.getResource(halResource, type, halLink.getHref(), true)); } else { resources.put(key, halClient.getResource(halResource, type, halLink.getHref(), true)); } } inner = Collections.unmodifiableMap(resources); } //------------------------------------------------------------- // Implementation - Map //------------------------------------------------------------- @Override public int size() { return inner.size(); } @Override public boolean isEmpty() { return inner.isEmpty(); } @Override public boolean containsKey(Object key) { return inner.containsKey(key); } @Override public boolean containsValue(Object value) { throw new UnsupportedOperationException(); } @Override public T get(Object key) { return inner.get(key); } @Override public T put(String key, T value) { throw new UnsupportedOperationException(); } @Override public T remove(Object key) { throw new UnsupportedOperationException(); } @Override public void putAll(Map<? extends String, ? extends T> m) { throw new UnsupportedOperationException(); } @Override public void clear() { throw new UnsupportedOperationException(); } @Override public Set<String> keySet() { return inner.keySet(); } @Override public Collection<T> values() { return inner.values(); } @Override public Set<Entry<String, T>> entrySet() { return inner.entrySet(); } //------------------------------------------------------------- // Methods - Private //------------------------------------------------------------- private String indexedRelation(String relation, int index) { return relation + "_" + index; } }