| /* |
| * 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.openjpa.lib.util; |
| |
| import java.sql.Timestamp; |
| |
| /** |
| * Helper base class attempts to return java.sql.Timestamp object with |
| * nanosecond precision. |
| * |
| * @author Albert Lee |
| */ |
| public class TimestampHelper { |
| |
| // number of millisecond, mircoseconds and nanoseconds in one second. |
| protected static final long MilliMuliplier = 1000L; |
| protected static final long MicroMuliplier = MilliMuliplier * 1000L; |
| protected static final long NanoMuliplier = MicroMuliplier * 1000L; |
| |
| // number of seconds passed 1970/1/1 00:00:00 GMT. |
| private static long sec0; |
| // fraction of seconds passed 1970/1/1 00:00:00 GMT, offset by |
| // the base System.nanoTime (nano0), in nanosecond unit. |
| private static long nano0; |
| |
| static { |
| // initialize base time in second and fraction of second (ns). |
| long curTime = System.currentTimeMillis(); |
| sec0 = curTime / MilliMuliplier; |
| nano0 = (curTime % MilliMuliplier) * MicroMuliplier - System.nanoTime(); |
| } |
| |
| /* |
| * Return a java.sql.Timestamp object of current time. |
| */ |
| public static Timestamp getNanoPrecisionTimestamp() { |
| long nano_delta = nano0 + System.nanoTime(); |
| long sec1 = sec0 + (nano_delta / NanoMuliplier); |
| long nano1 = nano_delta % NanoMuliplier; |
| |
| Timestamp rtnTs = new Timestamp(sec1 * MilliMuliplier); |
| rtnTs.setNanos((int) nano1); |
| return rtnTs; |
| } |
| } |