    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 *     https://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 */
    017package org.apache.commons.configuration2.interpol;
    018
    019import org.apache.commons.text.lookup.StringLookupFactory;
    020
    021/**
    022 * Enumerates built-in {@code Lookup} objects available for
    023 * {@code Configuration} instances.
    024 * <p>
    025 * When a new configuration object derived from {@code AbstractConfiguration} is created, it installs a
    026 * {@link ConfigurationInterpolator} containing a default set of {@link Lookup} objects. These lookups are
    027 * defined by this enumeration class, however not all lookups may be included in the defaults. See
    028 * {@link ConfigurationInterpolator#getDefaultPrefixLookups()} for details.
    029 * </p>
    030 * <p>
    031 * All the {@code Lookup}s defined here are state-less, thus their instances can be shared between multiple
    032 * configuration objects. Therefore, it makes sense to keep shared instances in this enumeration class.
    033 * </p>
    034 *
    035 * Provides access to lookups defined in Apache Commons Text:
    036 * <ul>
    037 * <li>"base64Decoder" for the {@code Base64DecoderStringLookup} since Apache Commons Text 1.6.</li>
    038 * <li>"base64Encoder" for the {@code Base64EncoderStringLookup} since Apache Commons Text 1.6.</li>
    039 * <li>"const" for the {@code ConstantStringLookup} since Apache Commons Text 1.5.</li>
    040 * <li>"date" for the {@code DateStringLookup}.</li>
    041 * <li>"env" for the {@code EnvironmentVariableStringLookup}.</li>
    042 * <li>"file" for the {@code FileStringLookup} since Apache Commons Text 1.5.</li>
    043 * <li>"java" for the {@code JavaPlatformStringLookup}.</li>
    044 * <li>"localhost" for the {@code LocalHostStringLookup}, see {@code #localHostStringLookup()} for key names; since
    045 * Apache Commons Text 1.3.</li>
    046 * <li>"properties" for the {@code PropertiesStringLookup} since Apache Commons Text 1.5.</li>
    047 * <li>"resourceBundle" for the {@code ResourceBundleStringLookup} since Apache Commons Text 1.5.</li>
    048 * <li>"script" for the {@code ScriptStringLookup} since Apache Commons Text 1.5.</li>
    049 * <li>"sys" for the {@code SystemPropertyStringLookup}.</li>
    050 * <li>"url" for the {@code UrlStringLookup} since Apache Commons Text 1.5.</li>
    051 * <li>"urlDecoder" for the {@code UrlDecoderStringLookup} since Apache Commons Text 1.6.</li>
    052 * <li>"urlEncoder" for the {@code UrlEncoderStringLookup} since Apache Commons Text 1.6.</li>
    053 * <li>"xml" for the {@code XmlStringLookup} since Apache Commons Text 1.5.</li>
    054 * </ul>
    055 *
    056 * @since 2.0
    057 */
    058public enum DefaultLookups {
    059
    060    /**
    061     * The lookup for Base64 decoding, accessed using the prefix {@code "base64Decoder"}.
    062     *
    063     * @see StringLookupFactory#base64DecoderStringLookup()
    064     * @since 2.4
    065     */
    066    BASE64_DECODER(StringLookupFactory.KEY_BASE64_DECODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.base64DecoderStringLookup())),
    067
    068    /**
    069     * The lookup for Base64 encoding, accessed using the prefix {@code "base64Encoder"}.
    070     *
    071     * @see StringLookupFactory#base64EncoderStringLookup()
    072     * @since 2.4
    073     */
    074    BASE64_ENCODER(StringLookupFactory.KEY_BASE64_ENCODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.base64EncoderStringLookup())),
    075
    076    /**
    077     * The lookup for Java constants, accessed using the prefix {@code "const"}.
    078     *
    079     * @see StringLookupFactory#constantStringLookup()
    080     * @since 2.4
    081     */
    082    CONST(StringLookupFactory.KEY_CONST, new StringLookupAdapter(StringLookupFactory.INSTANCE.constantStringLookup())),
    083
    084    /**
    085     * The lookup for the current date in a specified format, accessed using the prefix {@code "date"}.
    086     *
    087     * @see StringLookupFactory#dateStringLookup()
    088     * @since 2.4
    089     */
    090    DATE(StringLookupFactory.KEY_DATE, new StringLookupAdapter(StringLookupFactory.INSTANCE.dateStringLookup())),
    091
    092    /**
    093     * The lookup for DNS, accessed using the prefix {@code "dns"}.
    094     *
    095     * @see StringLookupFactory#dnsStringLookup()
    096     * @since 2.6
    097     */
    098    DNS(StringLookupFactory.KEY_DNS, new StringLookupAdapter(StringLookupFactory.INSTANCE.dnsStringLookup())),
    099
    100    /**
    101     * The lookup for environment properties, accessed using the prefix {@code "env"}.
    102     *
    103     * @see StringLookupFactory#environmentVariableStringLookup()
    104     */
    105    ENVIRONMENT(StringLookupFactory.KEY_ENV, new StringLookupAdapter(StringLookupFactory.INSTANCE.environmentVariableStringLookup())),
    106
    107    /**
    108     * The lookup for file content, accessed using the prefix {@code "file"}.
    109     *
    110     * @see StringLookupFactory#fileStringLookup()
    111     * @since 2.4
    112     */
    113    FILE(StringLookupFactory.KEY_FILE, new StringLookupAdapter(StringLookupFactory.INSTANCE.fileStringLookup())),
    114
    115    /**
    116     * The lookup for Java platform information, accessed using the prefix {@code "java"}.
    117     *
    118     * @see StringLookupFactory#javaPlatformStringLookup()
    119     * @since 2.4
    120     */
    121    JAVA(StringLookupFactory.KEY_JAVA, new StringLookupAdapter(StringLookupFactory.INSTANCE.javaPlatformStringLookup())),
    122
    123    /**
    124     * The lookup for localhost information, accessed using the prefix {@code "localhost"}.
    125     *
    126     * @see StringLookupFactory#localHostStringLookup()
    127     * @since 2.4
    128     */
    129    LOCAL_HOST(StringLookupFactory.KEY_LOCALHOST, new StringLookupAdapter(StringLookupFactory.INSTANCE.localHostStringLookup())),
    130
    131    /**
    132     * The lookup for properties, accessed using the prefix {@code "properties"}.
    133     *
    134     * @see StringLookupFactory#propertiesStringLookup()
    135     * @since 2.4
    136     */
    137    PROPERTIES(StringLookupFactory.KEY_PROPERTIES, new StringLookupAdapter(StringLookupFactory.INSTANCE.propertiesStringLookup())),
    138
    139    /**
    140     * The lookup for resource bundles, accessed using the prefix {@code "resourceBundle"}.
    141     *
    142     * @see StringLookupFactory#resourceBundleStringLookup()
    143     * @since 2.4
    144     */
    145    RESOURCE_BUNDLE(StringLookupFactory.KEY_RESOURCE_BUNDLE, new StringLookupAdapter(StringLookupFactory.INSTANCE.resourceBundleStringLookup())),
    146
    147    /**
    148     * The lookup for scripts, accessed using the prefix {@code "script"}.
    149     *
    150     * @see StringLookupFactory#scriptStringLookup()
    151     * @since 2.4
    152     */
    153    SCRIPT(StringLookupFactory.KEY_SCRIPT, new StringLookupAdapter(StringLookupFactory.INSTANCE.scriptStringLookup())),
    154
    155    /**
    156     * The lookup for system properties, accessed using the prefix {@code "sys"}.
    157     *
    158     * @see StringLookupFactory#systemPropertyStringLookup()
    159     */
    160    SYSTEM_PROPERTIES(StringLookupFactory.KEY_SYS, new StringLookupAdapter(StringLookupFactory.INSTANCE.systemPropertyStringLookup())),
    161
    162    /**
    163     * The lookup for URLs, accessed using the prefix {@code "url"}.
    164     *
    165     * @see StringLookupFactory#urlStringLookup()
    166     * @since 2.4
    167     */
    168    URL(StringLookupFactory.KEY_URL, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlStringLookup())),
    169
    170    /**
    171     * The lookup for URL decoding, accessed using the prefix {@code "urlDecoder"}.
    172     *
    173     * @see StringLookupFactory#urlDecoderStringLookup()
    174     * @since 2.4
    175     */
    176    URL_DECODER(StringLookupFactory.KEY_URL_DECODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlDecoderStringLookup())),
    177
    178    /**
    179     * The lookup for URL encoding, accessed using the prefix {@code "urlEncoder"}.
    180     *
    181     * @see StringLookupFactory#urlEncoderStringLookup()
    182     * @since 2.4
    183     */
    184    URL_ENCODER(StringLookupFactory.KEY_URL_ENCODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlEncoderStringLookup())),
    185
    186    /**
    187     * The lookup for XML content, accessed using the prefix {@code "xml"}.
    188     *
    189     * @see StringLookupFactory#xmlStringLookup()
    190     * @since 2.4
    191     */
    192    XML(StringLookupFactory.KEY_XML, new StringLookupAdapter(StringLookupFactory.INSTANCE.xmlStringLookup()));
    193
    194    /** The associated lookup instance. */
    195    private final Lookup lookup;
    196
    197    /** The prefix under which the associated lookup object is registered. */
    198    private final String prefix;
    199
    200    /**
    201     * Creates a new instance of {@code DefaultLookups} and sets the prefix and the associated lookup instance.
    202     *
    203     * @param prefix the prefix
    204     * @param lookup the {@code Lookup} instance
    205     */
    206    DefaultLookups(final String prefix, final Lookup lookup) {
    207        this.prefix = prefix;
    208        this.lookup = lookup;
    209    }
    210
    211    /**
    212     * Gets the standard {@code Lookup} instance of this kind.
    213     *
    214     * @return the associated {@code Lookup} object
    215     */
    216    public Lookup getLookup() {
    217        return lookup;
    218    }
    219
    220    /**
    221     * Gets the standard prefix for the lookup object of this kind.
    222     *
    223     * @return the prefix
    224     */
    225    public String getPrefix() {
    226        return prefix;
    227    }
    228}