+++ /dev/null
-package org.apache.lucene.queryParser.ext;
-
-/**
- * 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 java.util.Map;
-
-import org.apache.lucene.queryParser.QueryParser;
-
-/**
- * The {@link Extensions} class represents an extension mapping to associate
- * {@link ParserExtension} instances with extension keys. An extension key is a
- * string encoded into a Lucene standard query parser field symbol recognized by
- * {@link ExtendableQueryParser}. The query parser passes each extension field
- * token to {@link #splitExtensionField(String, String)} to separate the
- * extension key from the field identifier.
- * <p>
- * In addition to the key to extension mapping this class also defines the field
- * name overloading scheme. {@link ExtendableQueryParser} uses the given
- * extension to split the actual field name and extension key by calling
- * {@link #splitExtensionField(String, String)}. To change the order or the key
- * / field name encoding scheme users can subclass {@link Extensions} to
- * implement their own.
- *
- * @see ExtendableQueryParser
- * @see ParserExtension
- */
-public class Extensions {
- private final Map<String,ParserExtension> extensions = new HashMap<String,ParserExtension>();
- private final char extensionFieldDelimiter;
- /**
- * The default extension field delimiter character. This constant is set to
- * ':'
- */
- public static final char DEFAULT_EXTENSION_FIELD_DELIMITER = ':';
-
- /**
- * Creates a new {@link Extensions} instance with the
- * {@link #DEFAULT_EXTENSION_FIELD_DELIMITER} as a delimiter character.
- */
- public Extensions() {
- this(DEFAULT_EXTENSION_FIELD_DELIMITER);
- }
-
- /**
- * Creates a new {@link Extensions} instance
- *
- * @param extensionFieldDelimiter
- * the extensions field delimiter character
- */
- public Extensions(char extensionFieldDelimiter) {
- this.extensionFieldDelimiter = extensionFieldDelimiter;
- }
-
- /**
- * Adds a new {@link ParserExtension} instance associated with the given key.
- *
- * @param key
- * the parser extension key
- * @param extension
- * the parser extension
- */
- public void add(String key, ParserExtension extension) {
- this.extensions.put(key, extension);
- }
-
- /**
- * Returns the {@link ParserExtension} instance for the given key or
- * <code>null</code> if no extension can be found for the key.
- *
- * @param key
- * the extension key
- * @return the {@link ParserExtension} instance for the given key or
- * <code>null</code> if no extension can be found for the key.
- */
- public final ParserExtension getExtension(String key) {
- return this.extensions.get(key);
- }
-
- /**
- * Returns the extension field delimiter
- *
- * @return the extension field delimiter
- */
- public char getExtensionFieldDelimiter() {
- return extensionFieldDelimiter;
- }
-
- /**
- * Splits a extension field and returns the field / extension part as a
- * {@link Pair}. This method tries to split on the first occurrence of the
- * extension field delimiter, if the delimiter is not present in the string
- * the result will contain a <code>null</code> value for the extension key and
- * the given field string as the field value. If the given extension field
- * string contains no field identifier the result pair will carry the given
- * default field as the field value.
- *
- * @param defaultField
- * the default query field
- * @param field
- * the extension field string
- * @return a {@link Pair} with the field name as the {@link Pair#cur} and the
- * extension key as the {@link Pair#cud}
- */
- public Pair<String,String> splitExtensionField(String defaultField,
- String field) {
- int indexOf = field.indexOf(this.extensionFieldDelimiter);
- if (indexOf < 0)
- return new Pair<String,String>(field, null);
- final String indexField = indexOf == 0 ? defaultField : field.substring(0,
- indexOf);
- final String extensionKey = field.substring(indexOf + 1);
- return new Pair<String,String>(indexField, extensionKey);
-
- }
-
- /**
- * Escapes an extension field. The default implementation is equivalent to
- * {@link QueryParser#escape(String)}.
- *
- * @param extfield
- * the extension field identifier
- * @return the extension field identifier with all special chars escaped with
- * a backslash character.
- */
- public String escapeExtensionField(String extfield) {
- return QueryParser.escape(extfield);
- }
-
- /**
- * Builds an extension field string from a given extension key and the default
- * query field. The default field and the key are delimited with the extension
- * field delimiter character. This method makes no assumption about the order
- * of the extension key and the field. By default the extension key is
- * appended to the end of the returned string while the field is added to the
- * beginning. Special Query characters are escaped in the result.
- * <p>
- * Note: {@link Extensions} subclasses must maintain the contract between
- * {@link #buildExtensionField(String)} and
- * {@link #splitExtensionField(String, String)} where the latter inverts the
- * former.
- * </p>
- */
- public String buildExtensionField(String extensionKey) {
- return buildExtensionField(extensionKey, "");
- }
-
- /**
- * Builds an extension field string from a given extension key and the
- * extensions field. The field and the key are delimited with the extension
- * field delimiter character. This method makes no assumption about the order
- * of the extension key and the field. By default the extension key is
- * appended to the end of the returned string while the field is added to the
- * beginning. Special Query characters are escaped in the result.
- * <p>
- * Note: {@link Extensions} subclasses must maintain the contract between
- * {@link #buildExtensionField(String, String)} and
- * {@link #splitExtensionField(String, String)} where the latter inverts the
- * former.
- * </p>
- *
- * @param extensionKey
- * the extension key
- * @param field
- * the field to apply the extension on.
- * @return escaped extension field identifier
- * @see #buildExtensionField(String) to use the default query field
- */
- public String buildExtensionField(String extensionKey, String field) {
- StringBuilder builder = new StringBuilder(field);
- builder.append(this.extensionFieldDelimiter);
- builder.append(extensionKey);
- return escapeExtensionField(builder.toString());
- }
-
- /**
- * This class represents a generic pair.
- *
- * @param <Cur>
- * the pairs first element
- * @param <Cud>
- * the pairs last element of the pair.
- */
- public static class Pair<Cur,Cud> {
-
- public final Cur cur;
- public final Cud cud;
-
- /**
- * Creates a new Pair
- *
- * @param cur
- * the pairs first element
- * @param cud
- * the pairs last element
- */
- public Pair(Cur cur, Cud cud) {
- this.cur = cur;
- this.cud = cud;
- }
- }
-
-}
fnp / pylucene.git / blobdiff