package org.apache.lucene.search;
/**
* 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.io.Serializable;
import java.util.Locale;
/**
* Stores information about how to sort documents by terms in an individual
* field. Fields must be indexed in order to sort by them.
*
* <p>Created: Feb 11, 2004 1:25:29 PM
*
* @author Tim Jones (Nacimiento Software)
* @since lucene 1.4
* @version $Id: SortField.java 472959 2006-11-09 16:21:50Z yonik $
* @see Sort
*/
public class SortField
implements Serializable {
/** Sort by document score (relevancy). Sort values are Float and higher
* values are at the front. */
public static final int SCORE = 0;
/** Sort by document number (index order). Sort values are Integer and lower
* values are at the front. */
public static final int DOC = 1;
/** Guess type of sort based on field contents. A regular expression is used
* to look at the first term indexed for the field and determine if it
* represents an integer number, a floating point number, or just arbitrary
* string characters. */
public static final int AUTO = 2;
/** Sort using term values as Strings. Sort values are String and lower
* values are at the front. */
public static final int STRING = 3;
/** Sort using term values as encoded Integers. Sort values are Integer and
* lower values are at the front. */
public static final int INT = 4;
/** Sort using term values as encoded Floats. Sort values are Float and
* lower values are at the front. */
public static final int FLOAT = 5;
/** Sort using a custom Comparator. Sort values are any Comparable and
* sorting is done according to natural order. */
public static final int CUSTOM = 9;
// IMPLEMENTATION NOTE: the FieldCache.STRING_INDEX is in the same "namespace"
// as the above static int values. Any new values must not have the same value
// as FieldCache.STRING_INDEX.
/** Represents sorting by document score (relevancy). */
public static final SortField FIELD_SCORE = new SortField (null, SCORE);
/** Represents sorting by document number (index order). */
public static final SortField FIELD_DOC = new SortField (null, DOC);
private String field;
private int type = AUTO; // defaults to determining type dynamically
private Locale locale; // defaults to "natural order" (no Locale)
boolean reverse = false; // defaults to natural order
private SortComparatorSource factory;
/** Creates a sort by terms in the given field where the type of term value
* is determined dynamically ({@link #AUTO AUTO}).
* @param field Name of field to sort by, cannot be <code>null</code>.
*/
public SortField (String field) {
this.field = field.intern();
}
/** Creates a sort, possibly in reverse, by terms in the given field where
* the type of term value is determined dynamically ({@link #AUTO AUTO}).
* @param field Name of field to sort by, cannot be <code>null</code>.
* @param reverse True if natural order should be reversed.
*/
public SortField (String field, boolean reverse) {
this.field = field.intern();
this.reverse = reverse;
}
/** Creates a sort by terms in the given field with the type of term
* values explicitly given.
* @param field Name of field to sort by. Can be <code>null</code> if
* <code>type</code> is SCORE or DOC.
* @param type Type of values in the terms.
*/
public SortField (String field, int type) {
this.field = (field != null) ? field.intern() : field;
this.type = type;
}
/** Creates a sort, possibly in reverse, by terms in the given field with the
* type of term values explicitly given.
* @param field Name of field to sort by. Can be <code>null</code> if
* <code>type</code> is SCORE or DOC.
* @param type Type of values in the terms.
* @param reverse True if natural order should be reversed.
*/
public SortField (String field, int type, boolean reverse) {
this.field = (field != null) ? field.intern() : field;
this.type = type;
this.reverse = reverse;
}
/** Creates a sort by terms in the given field sorted
* according to the given locale.
* @param field Name of field to sort by, cannot be <code>null</code>.
* @param locale Locale of values in the field.
*/
public SortField (String field, Locale locale) {
this.field = field.intern();
this.type = STRING;
this.locale = locale;
}
/** Creates a sort, possibly in reverse, by terms in the given field sorted
* according to the given locale.
* @param field Name of field to sort by, cannot be <code>null</code>.
* @param locale Locale of values in the field.
*/
public SortField (String field, Locale locale, boolean reverse) {
this.field = field.intern();
this.type = STRING;
this.locale = locale;
this.reverse = reverse;
}
/** Creates a sort with a custom comparison function.
* @param field Name of field to sort by; cannot be <code>null</code>.
* @param comparator Returns a comparator for sorting hits.
*/
public SortField (String field, SortComparatorSource comparator) {
this.field = (field != null) ? field.intern() : field;
this.type = CUSTOM;
this.factory = comparator;
}
/** Creates a sort, possibly in reverse, with a custom comparison function.
* @param field Name of field to sort by; cannot be <code>null</code>.
* @param comparator Returns a comparator for sorting hits.
* @param reverse True if natural order should be reversed.
*/
public SortField (String field, SortComparatorSource comparator, boolean reverse) {
this.field = (field != null) ? field.intern() : field;
this.type = CUSTOM;
this.reverse = reverse;
this.factory = comparator;
}
/** Returns the name of the field. Could return <code>null</code>
* if the sort is by SCORE or DOC.
* @return Name of field, possibly <code>null</code>.
*/
public String getField() {
return field;
}
/** Returns the type of contents in the field.
* @return One of the constants SCORE, DOC, AUTO, STRING, INT or FLOAT.
*/
public int getType() {
return type;
}
/** Returns the Locale by which term values are interpreted.
* May return <code>null</code> if no Locale was specified.
* @return Locale, or <code>null</code>.
*/
public Locale getLocale() {
return locale;
}
/** Returns whether the sort should be reversed.
* @return True if natural order should be reversed.
*/
public boolean getReverse() {
return reverse;
}
public SortComparatorSource getFactory() {
return factory;
}
public String toString() {
StringBuffer buffer = new StringBuffer();
switch (type) {
case SCORE: buffer.append("<score>");
break;
case DOC: buffer.append("<doc>");
break;
case CUSTOM: buffer.append ("<custom:\"" + field + "\": "
+ factory + ">");
break;
default: buffer.append("\"" + field + "\"");
break;
}
if (locale != null) buffer.append ("("+locale+")");
if (reverse) buffer.append('!');
return buffer.toString();
}
}
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