-package org.apache.lucene.index;
-
-import org.apache.lucene.util.StringHelper;
-
-/**
- * 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.
- */
-
-/**
- A Term represents a word from text. This is the unit of search. It is
- composed of two elements, the text of the word, as a string, and the name of
- the field that the text occurred in, an interned string.
-
- Note that terms may represent more than words from text fields, but also
- things like dates, email addresses, urls, etc. */
-
-public final class Term implements Comparable<Term>, java.io.Serializable {
- String field;
- String text;
-
- /** Constructs a Term with the given field and text.
- * <p>Note that a null field or null text value results in undefined
- * behavior for most Lucene APIs that accept a Term parameter. */
- public Term(String fld, String txt) {
- field = StringHelper.intern(fld);
- text = txt;
- }
-
- /** Constructs a Term with the given field and empty text.
- * This serves two purposes: 1) reuse of a Term with the same field.
- * 2) pattern for a query.
- *
- * @param fld
- */
- public Term(String fld) {
- this(fld, "", true);
- }
-
- Term(String fld, String txt, boolean intern) {
- field = intern ? StringHelper.intern(fld) : fld; // field names are interned
- text = txt; // unless already known to be
- }
-
- /** Returns the field of this term, an interned string. The field indicates
- the part of a document which this term came from. */
- public final String field() { return field; }
-
- /** Returns the text of this term. In the case of words, this is simply the
- text of the word. In the case of dates and other types, this is an
- encoding of the object as a string. */
- public final String text() { return text; }
-
- /**
- * Optimized construction of new Terms by reusing same field as this Term
- * - avoids field.intern() overhead
- * @param text The text of the new term (field is implicitly same as this Term instance)
- * @return A new Term
- */
- public Term createTerm(String text)
- {
- return new Term(field,text,false);
- }
-
- @Override
- public boolean equals(Object obj) {
- if (this == obj)
- return true;
- if (obj == null)
- return false;
- if (getClass() != obj.getClass())
- return false;
- Term other = (Term) obj;
- if (field == null) {
- if (other.field != null)
- return false;
- } else if (field != other.field)
- return false;
- if (text == null) {
- if (other.text != null)
- return false;
- } else if (!text.equals(other.text))
- return false;
- return true;
- }
-
- @Override
- public int hashCode() {
- final int prime = 31;
- int result = 1;
- result = prime * result + ((field == null) ? 0 : field.hashCode());
- result = prime * result + ((text == null) ? 0 : text.hashCode());
- return result;
- }
-
- /** Compares two terms, returning a negative integer if this
- term belongs before the argument, zero if this term is equal to the
- argument, and a positive integer if this term belongs after the argument.
-
- The ordering of terms is first by field, then by text.*/
- public final int compareTo(Term other) {
- if (field == other.field) // fields are interned
- return text.compareTo(other.text);
- else
- return field.compareTo(other.field);
- }
-
- /** Resets the field and text of a Term. */
- final void set(String fld, String txt) {
- field = fld;
- text = txt;
- }
-
- @Override
- public final String toString() { return field + ":" + text; }
-
- private void readObject(java.io.ObjectInputStream in)
- throws java.io.IOException, ClassNotFoundException
- {
- in.defaultReadObject();
- field = StringHelper.intern(field);
- }
-}