Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.jclouds.openstack.swift.v1.functions; import java.util.Map; import java.util.Map.Entry; import com.google.common.base.Function; import com.google.common.collect.ImmutableMap; import com.google.common.collect.Multimap; /** * Extracts entries whose keys start with {@code .*-Meta-}. * * @param from * a {@link Multimap} containing the prefixed headers. * * @return the extracted metadata without the prefixed keys. */ public enum EntriesWithoutMetaPrefix implements Function<Multimap<String, String>, Map<String, String>> { INSTANCE; @Override public Map<String, String> apply(Multimap<String, String> arg0) { ImmutableMap.Builder<String, String> metadata = ImmutableMap.builder(); for (Entry<String, String> header : arg0.entries()) { int index = header.getKey().indexOf("-Meta-"); if (index != -1) { metadata.put(header.getKey().substring(index + 6), header.getValue()); } } return metadata.build(); } }