/*
* 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.
*/
package org.apache.jackrabbit.core.query.lucene;
import java.util.Date;
/**
* Implements <code>Date</code> <-> <code>String</code> conversions in
* a way that the resulting <code>String</code> is suitable for indexing and
* sorting.
*/
public class DateField {
private DateField() {
}
/**
* Date string length for about 3000 years
*/
private static final int DATE_LEN = Long.toString(1000L * 365 * 24 * 60 * 60 * 3000,
Character.MAX_RADIX).length();
/**
* Date shift of 2'000 years this allows dates back to 30 BC
*/
private static final long DATE_SHIFT = 1000L * 365 * 24 * 60 * 60 * 2000;
/**
* Returns '000000000' -> something around 30 BC
*/
public static final String MIN_DATE_STRING = timeToString(-DATE_SHIFT);
/**
* Returns 'zzzzzzzzz' -> something around 3189
*/
public static final String MAX_DATE_STRING;
/**
* Initializes the constant {@link #MAX_DATE_STRING}.
*/
static {
char[] buffer = new char[DATE_LEN];
char c = Character.forDigit(Character.MAX_RADIX - 1, Character.MAX_RADIX);
for (int i = 0; i < DATE_LEN; i++) {
buffer[i] = c;
}
MAX_DATE_STRING = new String(buffer);
}
/**
* Converts a Date to a string suitable for indexing. This method will throw
* a RuntimeException if the date specified in the method argument is before
* 30 BC or after 3189.
*/
public static String dateToString(Date date) {
return timeToString(date.getTime());
}
/**
* Converts a millisecond time to a string suitable for indexing.
* Supported date range is: 30 BC - 3189
* @throws IllegalArgumentException if the given <code>time</code> is not
* within the supported date range.
*/
public static String timeToString(long time) {
time += DATE_SHIFT;
if (time < 0) {
throw new IllegalArgumentException("time too early");
}
String s = Long.toString(time, Character.MAX_RADIX);
if (s.length() > DATE_LEN) {
throw new IllegalArgumentException("time too late");
}
// Pad with leading zeros
if (s.length() < DATE_LEN) {
StringBuffer sb = new StringBuffer(s);
while (sb.length() < DATE_LEN) {
sb.insert(0, 0);
}
s = sb.toString();
}
return s;
}
/**
* Converts a string-encoded date into a millisecond time.
*/
public static long stringToTime(String s) {
return Long.parseLong(s, Character.MAX_RADIX) - DATE_SHIFT;
}
/**
* Converts a string-encoded date into a Date object.
*/
public static Date stringToDate(String s) {
return new Date(stringToTime(s));
}
}