    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 */
    017package org.apache.commons.configuration2.interpol;
    018
    019import org.apache.commons.text.lookup.StringLookupFactory;
    020
    021/**
    022 * <p>
    023 * An enumeration class defining constants for built-in {@code Lookup} objects available for
    024 * {@code Configuration} instances.
    025 * </p>
    026 * <p>
    027 * When a new configuration object derived from {@code AbstractConfiguration} is created, it installs a
    028 * {@link ConfigurationInterpolator} containing a default set of {@link Lookup} objects. These lookups are
    029 * defined by this enumeration class, however not all lookups may be included in the defaults. See
    030 * {@link ConfigurationInterpolator#getDefaultPrefixLookups()} for details.
    031 * </p>
    032 * <p>
    033 * All the {@code Lookup}s defined here are state-less, thus their instances can be shared between multiple
    034 * configuration objects. Therefore, it makes sense to keep shared instances in this enumeration class.
    035 * </p>
    036 *
    037 * Provides access to lookups defined in Apache Commons Text:
    038 * <ul>
    039 * <li>"base64Decoder" for the {@code Base64DecoderStringLookup} since Apache Commons Text 1.6.</li>
    040 * <li>"base64Encoder" for the {@code Base64EncoderStringLookup} since Apache Commons Text 1.6.</li>
    041 * <li>"const" for the {@code ConstantStringLookup} since Apache Commons Text 1.5.</li>
    042 * <li>"date" for the {@code DateStringLookup}.</li>
    043 * <li>"env" for the {@code EnvironmentVariableStringLookup}.</li>
    044 * <li>"file" for the {@code FileStringLookup} since Apache Commons Text 1.5.</li>
    045 * <li>"java" for the {@code JavaPlatformStringLookup}.</li>
    046 * <li>"localhost" for the {@code LocalHostStringLookup}, see {@code #localHostStringLookup()} for key names; since
    047 * Apache Commons Text 1.3.</li>
    048 * <li>"properties" for the {@code PropertiesStringLookup} since Apache Commons Text 1.5.</li>
    049 * <li>"resourceBundle" for the {@code ResourceBundleStringLookup} since Apache Commons Text 1.5.</li>
    050 * <li>"script" for the {@code ScriptStringLookup} since Apache Commons Text 1.5.</li>
    051 * <li>"sys" for the {@code SystemPropertyStringLookup}.</li>
    052 * <li>"url" for the {@code UrlStringLookup} since Apache Commons Text 1.5.</li>
    053 * <li>"urlDecoder" for the {@code UrlDecoderStringLookup} since Apache Commons Text 1.6.</li>
    054 * <li>"urlEncoder" for the {@code UrlEncoderStringLookup} since Apache Commons Text 1.6.</li>
    055 * <li>"xml" for the {@code XmlStringLookup} since Apache Commons Text 1.5.</li>
    056 * </ul>
    057 *
    058 * @since 2.0
    059 */
    060public enum DefaultLookups {
    061
    062    /**
    063     * The lookup for Base64 decoding, accessed using the prefix {@code "base64Decoder"}.
    064     *
    065     * @see StringLookupFactory#base64DecoderStringLookup()
    066     * @since 2.4
    067     */
    068    BASE64_DECODER(StringLookupFactory.KEY_BASE64_DECODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.base64DecoderStringLookup())),
    069
    070    /**
    071     * The lookup for Base64 encoding, accessed using the prefix {@code "base64Encoder"}.
    072     *
    073     * @see StringLookupFactory#base64EncoderStringLookup()
    074     * @since 2.4
    075     */
    076    BASE64_ENCODER(StringLookupFactory.KEY_BASE64_ENCODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.base64EncoderStringLookup())),
    077
    078    /**
    079     * The lookup for Java constants, accessed using the prefix {@code "const"}.
    080     *
    081     * @see StringLookupFactory#constantStringLookup()
    082     * @since 2.4
    083     */
    084    CONST(StringLookupFactory.KEY_CONST, new StringLookupAdapter(StringLookupFactory.INSTANCE.constantStringLookup())),
    085
    086    /**
    087     * The lookup for the current date in a specified format, accessed using the prefix {@code "date"}.
    088     *
    089     * @see StringLookupFactory#dateStringLookup()
    090     * @since 2.4
    091     */
    092    DATE(StringLookupFactory.KEY_DATE, new StringLookupAdapter(StringLookupFactory.INSTANCE.dateStringLookup())),
    093
    094    /**
    095     * The lookup for DNS, accessed using the prefix {@code "dns"}.
    096     *
    097     * @see StringLookupFactory#dnsStringLookup()
    098     * @since 2.6
    099     */
    100    DNS(StringLookupFactory.KEY_DNS, new StringLookupAdapter(StringLookupFactory.INSTANCE.dnsStringLookup())),
    101
    102    /**
    103     * The lookup for environment properties, accessed using the prefix {@code "env"}.
    104     *
    105     * @see StringLookupFactory#environmentVariableStringLookup()
    106     */
    107    ENVIRONMENT(StringLookupFactory.KEY_ENV, new StringLookupAdapter(StringLookupFactory.INSTANCE.environmentVariableStringLookup())),
    108
    109    /**
    110     * The lookup for file content, accessed using the prefix {@code "file"}.
    111     *
    112     * @see StringLookupFactory#fileStringLookup()
    113     * @since 2.4
    114     */
    115    FILE(StringLookupFactory.KEY_FILE, new StringLookupAdapter(StringLookupFactory.INSTANCE.fileStringLookup())),
    116
    117    /**
    118     * The lookup for Java platform information, accessed using the prefix {@code "java"}.
    119     *
    120     * @see StringLookupFactory#javaPlatformStringLookup()
    121     * @since 2.4
    122     */
    123    JAVA(StringLookupFactory.KEY_JAVA, new StringLookupAdapter(StringLookupFactory.INSTANCE.javaPlatformStringLookup())),
    124
    125    /**
    126     * The lookup for localhost information, accessed using the prefix {@code "localhost"}.
    127     *
    128     * @see StringLookupFactory#localHostStringLookup()
    129     * @since 2.4
    130     */
    131    LOCAL_HOST(StringLookupFactory.KEY_LOCALHOST, new StringLookupAdapter(StringLookupFactory.INSTANCE.localHostStringLookup())),
    132
    133    /**
    134     * The lookup for properties, accessed using the prefix {@code "properties"}.
    135     *
    136     * @see StringLookupFactory#propertiesStringLookup()
    137     * @since 2.4
    138     */
    139    PROPERTIES(StringLookupFactory.KEY_PROPERTIES, new StringLookupAdapter(StringLookupFactory.INSTANCE.propertiesStringLookup())),
    140
    141    /**
    142     * The lookup for resource bundles, accessed using the prefix {@code "resourceBundle"}.
    143     *
    144     * @see StringLookupFactory#resourceBundleStringLookup()
    145     * @since 2.4
    146     */
    147    RESOURCE_BUNDLE(StringLookupFactory.KEY_RESOURCE_BUNDLE, new StringLookupAdapter(StringLookupFactory.INSTANCE.resourceBundleStringLookup())),
    148
    149    /**
    150     * The lookup for scripts, accessed using the prefix {@code "script"}.
    151     *
    152     * @see StringLookupFactory#scriptStringLookup()
    153     * @since 2.4
    154     */
    155    SCRIPT(StringLookupFactory.KEY_SCRIPT, new StringLookupAdapter(StringLookupFactory.INSTANCE.scriptStringLookup())),
    156
    157    /**
    158     * The lookup for system properties, accessed using the prefix {@code "sys"}.
    159     *
    160     * @see StringLookupFactory#systemPropertyStringLookup()
    161     */
    162    SYSTEM_PROPERTIES(StringLookupFactory.KEY_SYS, new StringLookupAdapter(StringLookupFactory.INSTANCE.systemPropertyStringLookup())),
    163
    164    /**
    165     * The lookup for URLs, accessed using the prefix {@code "url"}.
    166     *
    167     * @see StringLookupFactory#urlStringLookup()
    168     * @since 2.4
    169     */
    170    URL(StringLookupFactory.KEY_URL, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlStringLookup())),
    171
    172    /**
    173     * The lookup for URL decoding, accessed using the prefix {@code "urlDecoder"}.
    174     *
    175     * @see StringLookupFactory#urlDecoderStringLookup()
    176     * @since 2.4
    177     */
    178    URL_DECODER(StringLookupFactory.KEY_URL_DECODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlDecoderStringLookup())),
    179
    180    /**
    181     * The lookup for URL encoding, accessed using the prefix {@code "urlEncoder"}.
    182     *
    183     * @see StringLookupFactory#urlEncoderStringLookup()
    184     * @since 2.4
    185     */
    186    URL_ENCODER(StringLookupFactory.KEY_URL_ENCODER, new StringLookupAdapter(StringLookupFactory.INSTANCE.urlEncoderStringLookup())),
    187
    188    /**
    189     * The lookup for XML content, accessed using the prefix {@code "xml"}.
    190     *
    191     * @see StringLookupFactory#xmlStringLookup()
    192     * @since 2.4
    193     */
    194    XML(StringLookupFactory.KEY_XML, new StringLookupAdapter(StringLookupFactory.INSTANCE.xmlStringLookup()));
    195
    196    /** The associated lookup instance. */
    197    private final Lookup lookup;
    198
    199    /** The prefix under which the associated lookup object is registered. */
    200    private final String prefix;
    201
    202    /**
    203     * Creates a new instance of {@code DefaultLookups} and sets the prefix and the associated lookup instance.
    204     *
    205     * @param prefix the prefix
    206     * @param lookup the {@code Lookup} instance
    207     */
    208    DefaultLookups(final String prefix, final Lookup lookup) {
    209        this.prefix = prefix;
    210        this.lookup = lookup;
    211    }
    212
    213    /**
    214     * Returns the standard {@code Lookup} instance of this kind.
    215     *
    216     * @return the associated {@code Lookup} object
    217     */
    218    public Lookup getLookup() {
    219        return lookup;
    220    }
    221
    222    /**
    223     * Returns the standard prefix for the lookup object of this kind.
    224     *
    225     * @return the prefix
    226     */
    227    public String getPrefix() {
    228        return prefix;
    229    }
    230}