| /* |
| * 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; |
| |
| import java.util.Map; |
| import java.util.ResourceBundle; |
| |
| import org.apache.commons.text.lookup.StringLookup; |
| import org.apache.commons.text.lookup.StringLookupFactory; |
| |
| /** |
| * Lookup a String key to a String value. |
| * <p> |
| * This class represents the simplest form of a string to string map. It has a benefit over a map in that it can create |
| * the result on demand based on the key. |
| * <p> |
| * This class comes complete with various factory methods. If these do not suffice, you can subclass and implement your |
| * own matcher. |
| * <p> |
| * For example, it would be possible to implement a lookup that used the key as a primary key, and looked up the value |
| * on demand from the database |
| * |
| * @param <V> the type of the values supported by the lookup |
| * @since 1.0 |
| * @deprecated Deprecated as of 1.3, use {@link StringLookupFactory} instead. This class will be removed in 2.0. |
| */ |
| @Deprecated |
| public abstract class StrLookup<V> implements StringLookup { |
| |
| /** |
| * Lookup that always returns null. |
| */ |
| private static final StrLookup<String> NONE_LOOKUP = new MapStrLookup<>(null); |
| |
| /** |
| * Lookup based on system properties. |
| */ |
| private static final StrLookup<String> SYSTEM_PROPERTIES_LOOKUP = new SystemPropertiesStrLookup(); |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Returns a lookup which always returns null. |
| * |
| * @return a lookup that always returns null, not null |
| */ |
| public static StrLookup<?> noneLookup() { |
| return NONE_LOOKUP; |
| } |
| |
| /** |
| * Returns a new lookup which uses a copy of the current {@link System#getProperties() System properties}. |
| * <p> |
| * If a security manager blocked access to system properties, then null will be returned from every lookup. |
| * <p> |
| * If a null key is used, this lookup will throw a NullPointerException. |
| * |
| * @return a lookup using system properties, not null |
| */ |
| public static StrLookup<String> systemPropertiesLookup() { |
| return SYSTEM_PROPERTIES_LOOKUP; |
| } |
| |
| /** |
| * Returns a lookup which looks up values using a map. |
| * <p> |
| * If the map is null, then null will be returned from every lookup. The map result object is converted to a string |
| * using toString(). |
| * |
| * @param <V> the type of the values supported by the lookup |
| * @param map the map of keys to values, may be null |
| * @return a lookup using the map, not null |
| */ |
| public static <V> StrLookup<V> mapLookup(final Map<String, V> map) { |
| return new MapStrLookup<>(map); |
| } |
| |
| /** |
| * Returns a lookup which looks up values using a ResourceBundle. |
| * <p> |
| * If the ResourceBundle is null, then null will be returned from every lookup. The map result object is converted |
| * to a string using toString(). |
| * |
| * @param resourceBundle the map of keys to values, may be null |
| * @return a lookup using the map, not null |
| * @see StringLookupFactory#resourceBundleStringLookup(String) |
| */ |
| public static StrLookup<String> resourceBundleLookup(final ResourceBundle resourceBundle) { |
| return new ResourceBundleLookup(resourceBundle); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Constructor. |
| */ |
| protected StrLookup() { |
| super(); |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Lookup implementation that uses a Map. |
| * |
| * @param <V> the type of the values supported by the lookup |
| */ |
| static class MapStrLookup<V> extends StrLookup<V> { |
| |
| /** Map keys are variable names and value. */ |
| private final Map<String, V> map; |
| |
| /** |
| * Creates a new instance backed by a Map. |
| * |
| * @param map the map of keys to values, may be null |
| */ |
| MapStrLookup(final Map<String, V> map) { |
| this.map = map; |
| } |
| |
| /** |
| * Looks up a String key to a String value using the map. |
| * <p> |
| * If the map is null, then null is returned. The map result object is converted to a string using toString(). |
| * |
| * @param key the key to be looked up, may be null |
| * @return The matching value, null if no match |
| */ |
| @Override |
| public String lookup(final String key) { |
| if (map == null) { |
| return null; |
| } |
| final Object obj = map.get(key); |
| if (obj == null) { |
| return null; |
| } |
| return obj.toString(); |
| } |
| |
| @Override |
| public String toString() { |
| return super.toString() + " [map=" + map + "]"; |
| } |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Lookup implementation based on a ResourceBundle. |
| */ |
| private static final class ResourceBundleLookup extends StrLookup<String> { |
| |
| /** ResourceBundle keys are variable names and value. */ |
| private final ResourceBundle resourceBundle; |
| |
| /** |
| * Creates a new instance backed by a ResourceBundle. |
| * |
| * @param resourceBundle the ResourceBundle of keys to values, may be null |
| */ |
| private ResourceBundleLookup(final ResourceBundle resourceBundle) { |
| this.resourceBundle = resourceBundle; |
| } |
| |
| @Override |
| public String lookup(final String key) { |
| if (resourceBundle == null || key == null || !resourceBundle.containsKey(key)) { |
| return null; |
| } |
| return resourceBundle.getString(key); |
| } |
| |
| @Override |
| public String toString() { |
| return super.toString() + " [resourceBundle=" + resourceBundle + "]"; |
| } |
| |
| } |
| |
| // ----------------------------------------------------------------------- |
| /** |
| * Lookup implementation based on system properties. |
| */ |
| private static final class SystemPropertiesStrLookup extends StrLookup<String> { |
| /** |
| * {@inheritDoc} This implementation directly accesses system properties. |
| */ |
| @Override |
| public String lookup(final String key) { |
| if (key.length() > 0) { |
| try { |
| return System.getProperty(key); |
| } catch (final SecurityException scex) { |
| // Squelched. All lookup(String) will return null. |
| return null; |
| } |
| } |
| return null; |
| } |
| } |
| } |