Java tutorial
/* * 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 gobblin.source.extractor.extract; import java.math.RoundingMode; import com.google.common.base.Preconditions; import com.google.common.math.LongMath; import com.google.common.primitives.Longs; import com.google.gson.Gson; import com.google.gson.JsonElement; import gobblin.source.extractor.ComparableWatermark; import gobblin.source.extractor.Watermark; import lombok.EqualsAndHashCode; import lombok.Getter; import lombok.Setter; import lombok.ToString; @ToString @EqualsAndHashCode public class LongWatermark implements ComparableWatermark { private static final Gson GSON = new Gson(); @Getter @Setter private long value; public LongWatermark(long value) { this.value = value; } public void increment() { this.value++; } @Override public JsonElement toJson() { return GSON.toJsonTree(this); } @Override public short calculatePercentCompletion(Watermark lowWatermark, Watermark highWatermark) { Preconditions.checkArgument(lowWatermark instanceof LongWatermark); Preconditions.checkArgument(highWatermark instanceof LongWatermark); long total = ((LongWatermark) highWatermark).value - ((LongWatermark) lowWatermark).value; long pulled = this.value - ((LongWatermark) lowWatermark).value; Preconditions.checkState(total >= 0); Preconditions.checkState(pulled >= 0); if (total == 0) { return 0; } long percent = Math.min(100, LongMath.divide(pulled * 100, total, RoundingMode.HALF_UP)); return (short) percent; } @Override public int compareTo(ComparableWatermark other) { Preconditions.checkArgument(other instanceof LongWatermark); return Longs.compare(this.value, ((LongWatermark) other).value); } }