| /* |
| * 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.apache.commons.text.lookup; |
| |
| import java.util.Collections; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| import java.util.stream.Collectors; |
| |
| /** |
| * Proxies other {@link StringLookup}s using a keys within ${} markers using the format "${StringLookup:Key}". |
| * <p> |
| * Uses the {@link StringLookupFactory default lookups}. |
| * </p> |
| */ |
| final class InterpolatorStringLookup extends AbstractStringLookup { |
| |
| /** |
| * Defines the singleton for this class. |
| * |
| * @since 1.6 |
| */ |
| static final AbstractStringLookup INSTANCE = new InterpolatorStringLookup(); |
| |
| /** Constant for the prefix separator. */ |
| private static final char PREFIX_SEPARATOR = ':'; |
| |
| /** The default string lookup. */ |
| private final StringLookup defaultStringLookup; |
| |
| /** The map of String lookups keyed by prefix. */ |
| private final Map<String, StringLookup> stringLookupMap; |
| |
| /** |
| * Constructs an instance using only lookups that work without initial properties and are stateless. |
| * <p> |
| * Uses the {@link StringLookupFactory default lookups}. |
| * </p> |
| */ |
| InterpolatorStringLookup() { |
| this((Map<String, String>) null); |
| } |
| |
| /** |
| * Constructs a fully customized instance. |
| * |
| * @param stringLookupMap the map of string lookups. |
| * @param defaultStringLookup the default string lookup. |
| * @param addDefaultLookups whether the default lookups should be used. |
| */ |
| InterpolatorStringLookup(final Map<String, StringLookup> stringLookupMap, final StringLookup defaultStringLookup, |
| final boolean addDefaultLookups) { |
| this.defaultStringLookup = defaultStringLookup; |
| this.stringLookupMap = stringLookupMap.entrySet().stream().collect(Collectors.toMap(e -> StringLookupFactory.toKey(e.getKey()), Entry::getValue)); |
| if (addDefaultLookups) { |
| StringLookupFactory.INSTANCE.addDefaultStringLookups(this.stringLookupMap); |
| } |
| } |
| |
| /** |
| * Constructs an instance using only lookups that work without initial properties and are stateless. |
| * <p> |
| * Uses the {@link StringLookupFactory default lookups}. |
| * </p> |
| * |
| * @param <V> the map's value type. |
| * @param defaultMap the default map for string lookups. |
| */ |
| <V> InterpolatorStringLookup(final Map<String, V> defaultMap) { |
| this(StringLookupFactory.INSTANCE.mapStringLookup(defaultMap)); |
| } |
| |
| /** |
| * Constructs an instance with the given lookup. |
| * |
| * @param defaultStringLookup the default lookup. |
| */ |
| InterpolatorStringLookup(final StringLookup defaultStringLookup) { |
| this(Collections.emptyMap(), defaultStringLookup, true); |
| } |
| |
| /** |
| * Gets the lookup map. |
| * |
| * @return The lookup map. |
| */ |
| public Map<String, StringLookup> getStringLookupMap() { |
| return stringLookupMap; |
| } |
| |
| /** |
| * Resolves the specified variable. This implementation will try to extract a variable prefix from the given |
| * variable name (the first colon (':') is used as prefix separator). It then passes the name of the variable with |
| * the prefix stripped to the lookup object registered for this prefix. If no prefix can be found or if the |
| * associated lookup object cannot resolve this variable, the default lookup object will be used. |
| * |
| * @param key the name of the variable whose value is to be looked up |
| * @return The value of this variable or <b>null</b> if it cannot be resolved |
| */ |
| @Override |
| public String lookup(String key) { |
| if (key == null) { |
| return null; |
| } |
| |
| final int prefixPos = key.indexOf(PREFIX_SEPARATOR); |
| if (prefixPos >= 0) { |
| final String prefix = StringLookupFactory.toKey(key.substring(0, prefixPos)); |
| final String name = key.substring(prefixPos + 1); |
| final StringLookup lookup = stringLookupMap.get(prefix); |
| String value = null; |
| if (lookup != null) { |
| value = lookup.lookup(name); |
| } |
| |
| if (value != null) { |
| return value; |
| } |
| key = key.substring(prefixPos + 1); |
| } |
| if (defaultStringLookup != null) { |
| return defaultStringLookup.lookup(key); |
| } |
| return null; |
| } |
| |
| @Override |
| public String toString() { |
| return super.toString() + " [stringLookupMap=" + stringLookupMap + ", defaultStringLookup=" |
| + defaultStringLookup + "]"; |
| } |
| } |