package org.apache.lucene.search.regex;
/**
* 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.regex.Pattern;
/**
* An implementation tying Java's built-in java.util.regex to RegexQuery.
*
* Note that because this implementation currently only returns null from
* {@link #prefix} that queries using this implementation will enumerate and
* attempt to {@link #match} each term for the specified field in the index.
*/
public class JavaUtilRegexCapabilities implements RegexCapabilities {
private Pattern pattern;
private int flags = 0;
// Define the optional flags from Pattern that can be used.
// Do this here to keep Pattern contained within this class.
public static final int FLAG_CANON_EQ = Pattern.CANON_EQ;
public static final int FLAG_CASE_INSENSITIVE = Pattern.CASE_INSENSITIVE;
public static final int FLAG_COMMENTS = Pattern.COMMENTS;
public static final int FLAG_DOTALL = Pattern.DOTALL;
public static final int FLAG_LITERAL = Pattern.LITERAL;
public static final int FLAG_MULTILINE = Pattern.MULTILINE;
public static final int FLAG_UNICODE_CASE = Pattern.UNICODE_CASE;
public static final int FLAG_UNIX_LINES = Pattern.UNIX_LINES;
/**
* Default constructor that uses java.util.regex.Pattern
* with its default flags.
*/
public JavaUtilRegexCapabilities() {
this.flags = 0;
}
/**
* Constructor that allows for the modification of the flags that
* the java.util.regex.Pattern will use to compile the regular expression.
* This gives the user the ability to fine-tune how the regular expression
* to match the functionality that they need.
* The {@link java.util.regex.Pattern Pattern} class supports specifying
* these fields via the regular expression text itself, but this gives the caller
* another option to modify the behavior. Useful in cases where the regular expression text
* cannot be modified, or if doing so is undesired.
*
* @param flags The flags that are ORed together.
*/
public JavaUtilRegexCapabilities(int flags) {
this.flags = flags;
}
public void compile(String pattern) {
this.pattern = Pattern.compile(pattern, this.flags);
}
public boolean match(String string) {
return pattern.matcher(string).matches();
}
public String prefix() {
return null;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
final JavaUtilRegexCapabilities that = (JavaUtilRegexCapabilities) o;
if (pattern != null ? !pattern.equals(that.pattern) : that.pattern != null) return false;
return true;
}
@Override
public int hashCode() {
return (pattern != null ? pattern.hashCode() : 0);
}
}