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. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.http.entity.mime; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Locale; import java.util.Map; /** * The header of an entity (see RFC 2045). */ public class Header implements Iterable<MinimalField> { private final List<MinimalField> fields; private final Map<String, List<MinimalField>> fieldMap; public Header() { super(); this.fields = new LinkedList<MinimalField>(); this.fieldMap = new HashMap<String, List<MinimalField>>(); } public void addField(final MinimalField field) { if (field == null) { return; } String key = field.getName().toLowerCase(Locale.US); List<MinimalField> values = this.fieldMap.get(key); if (values == null) { values = new LinkedList<MinimalField>(); this.fieldMap.put(key, values); } values.add(field); this.fields.add(field); } public List<MinimalField> getFields() { return new ArrayList<MinimalField>(this.fields); } public MinimalField getField(final String name) { if (name == null) { return null; } String key = name.toLowerCase(Locale.US); List<MinimalField> list = this.fieldMap.get(key); if (list != null && !list.isEmpty()) { return list.get(0); } return null; } public List<MinimalField> getFields(final String name) { if (name == null) { return null; } String key = name.toLowerCase(Locale.US); List<MinimalField> list = this.fieldMap.get(key); if (list == null || list.isEmpty()) { return Collections.emptyList(); } else { return new ArrayList<MinimalField>(list); } } public int removeFields(final String name) { if (name == null) { return 0; } String key = name.toLowerCase(Locale.US); List<MinimalField> removed = fieldMap.remove(key); if (removed == null || removed.isEmpty()) { return 0; } this.fields.removeAll(removed); return removed.size(); } public void setField(final MinimalField field) { if (field == null) { return; } String key = field.getName().toLowerCase(Locale.US); List<MinimalField> list = fieldMap.get(key); if (list == null || list.isEmpty()) { addField(field); return; } list.clear(); list.add(field); int firstOccurrence = -1; int index = 0; for (Iterator<MinimalField> it = this.fields.iterator(); it.hasNext(); index++) { MinimalField f = it.next(); if (f.getName().equalsIgnoreCase(field.getName())) { it.remove(); if (firstOccurrence == -1) { firstOccurrence = index; } } } this.fields.add(firstOccurrence, field); } public Iterator<MinimalField> iterator() { return Collections.unmodifiableList(fields).iterator(); } @Override public String toString() { return this.fields.toString(); } }