001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.configuration2.web;
019
020import java.util.Collections;
021import java.util.Enumeration;
022import java.util.Iterator;
023import java.util.Objects;
024
025import javax.servlet.FilterConfig;
026
027/**
028 * A configuration wrapper around a {@link FilterConfig}. This configuration is read only, adding or removing a property
029 * will throw an UnsupportedOperationException.
030 *
031 * @since 1.1
032 */
033public class ServletFilterConfiguration extends BaseWebConfiguration {
034
035    /** Stores the wrapped filter config. */
036    protected FilterConfig config;
037
038    /**
039     * Create a ServletFilterConfiguration using the filter initialization parameters.
040     *
041     * @param config the filter configuration
042     */
043    public ServletFilterConfiguration(final FilterConfig config) {
044        this.config = Objects.requireNonNull(config, "config");
045    }
046
047    @Override
048    protected Iterator<String> getKeysInternal() {
049        // According to the documentation of getInitParameterNames() the
050        // enumeration is of type String.
051        final Enumeration<String> en = config.getInitParameterNames();
052        return Collections.list(en).iterator();
053    }
054
055    @Override
056    protected Object getPropertyInternal(final String key) {
057        return handleDelimiters(config.getInitParameter(key));
058    }
059}