package org.apache.lucene.queryParser.core.config;
/**
* 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.
*/
import java.util.HashMap;
import org.apache.lucene.util.Attribute;
import org.apache.lucene.util.AttributeSource;
/**
* <p>
* This class is the base of {@link QueryConfigHandler} and {@link FieldConfig}.
* It has operations to set, unset and get configuration values.
* </p>
* <p>
* Each configuration is is a key->value pair. The key should be an unique
* {@link ConfigurationKey} instance and it also holds the value's type.
* </p>
*
* NOTE: in future this class will no longer extend {@link AttributeSource}
*
* @see ConfigurationKey
*/
public abstract class AbstractQueryConfig extends AttributeSource {
final private HashMap<ConfigurationKey<?>, Object> configMap = new HashMap<ConfigurationKey<?>, Object>();
AbstractQueryConfig() {
// although this class is public, it can only be constructed from package
}
/**
* Returns the value held by the given key.
*
* @param <T> the value's type
*
* @param key the key, cannot be <code>null</code>
*
* @return the value held by the given key
*/
@SuppressWarnings("unchecked")
public <T> T get(ConfigurationKey<T> key) {
if (key == null) {
throw new IllegalArgumentException("key cannot be null!");
}
return (T) this.configMap.get(key);
}
/**
* Returns the value held by the given key or the given default value if the
* key is not found.
*
* @param <T> the value's type
*
* @param key the key, cannot be <code>null</code>
* @param defaultValue the default value
*
* @return the value held by the given key or the default value
*/
@SuppressWarnings("unchecked")
public <T> T get(ConfigurationKey<T> key, T defaultValue) {
if (key == null) {
throw new IllegalArgumentException("key cannot be null!");
}
if (this.configMap.containsKey(key)) {
return (T) this.configMap.get(key);
} else {
return defaultValue;
}
}
/**
* Returns true if there is a value set with the given key, otherwise false.
*
* @param <T> @param <T> the value's type
* @param key the key, cannot be <code>null</code>
* @return true if there is a value set with the given key, otherwise false
*/
public <T> boolean has(ConfigurationKey<T> key) {
if (key == null) {
throw new IllegalArgumentException("key cannot be null!");
}
return this.configMap.containsKey(key);
}
/**
* Sets a key and its value.
*
* @param <T> the value's type
* @param key the key, cannot be <code>null</code>
* @param value
*/
public <T> void set(ConfigurationKey<T> key, T value) {
if (key == null) {
throw new IllegalArgumentException("key cannot be null!");
}
if (value == null) {
unset(key);
} else {
this.configMap.put(key, value);
}
}
@SuppressWarnings("deprecation")
@Override
public <A extends Attribute> A addAttribute(Class<A> attClass) {
if (hasAttribute(attClass)) {
return getAttribute(attClass);
} else {
A attr = super.addAttribute(attClass);
if (attr instanceof ConfigAttribute) {
((ConfigAttribute) attr).setQueryConfigHandler(this);
}
return attr;
}
}
/**
* Unsets the given key and its value.
*
* @param <T> the value's type
* @param key the key
* @return true if the key and value was set and removed, otherwise false
*/
public <T> boolean unset(ConfigurationKey<T> key) {
if (key == null) {
throw new IllegalArgumentException("key cannot be null!");
}
return this.configMap.remove(key) != null;
}
}