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 org.apache.kylin.engine.mr.steps; import java.io.DataInput; import java.io.DataOutput; import java.io.IOException; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.WritableComparable; import org.apache.kylin.metadata.datatype.DataType; public class SelfDefineSortableKey implements WritableComparable<SelfDefineSortableKey> { public enum TypeFlag { NONE_NUMERIC_TYPE, INTEGER_FAMILY_TYPE, DOUBLE_FAMILY_TYPE } private byte typeId; //non-numeric(0000 0000) int(0000 0001) other numberic(0000 0010) private Text rawKey; private Object keyInObj; public SelfDefineSortableKey() { } public SelfDefineSortableKey(Text key, DataType type) { init(key, getTypeIdByDatatype(type)); } public void init(Text key, byte typeId) { this.typeId = typeId; this.rawKey = key; if (isNumberFamily()) { String valueStr = new String(key.getBytes(), 1, key.getLength() - 1); if (isIntegerFamily()) { this.keyInObj = Long.parseLong(valueStr); } else { this.keyInObj = Double.parseDouble(valueStr); } } else { this.keyInObj = key; } } public void init(Text key, DataType type) { init(key, getTypeIdByDatatype(type)); } @Override public int compareTo(SelfDefineSortableKey o) { if (this.typeId != o.typeId) throw new IllegalStateException("Error. Incompatible types"); if (!isNumberFamily()) { return ((Text) this.keyInObj).compareTo(((Text) o.keyInObj)); } else { if (isIntegerFamily()) { return Long.compare((Long) this.keyInObj, (Long) o.keyInObj); } else { return Double.compare((Double) this.keyInObj, (Double) o.keyInObj); } } } @Override public void write(DataOutput dataOutput) throws IOException { dataOutput.writeByte(typeId); rawKey.write(dataOutput); } @Override public void readFields(DataInput dataInput) throws IOException { this.typeId = dataInput.readByte(); Text inputKey = new Text(); inputKey.readFields(dataInput); init(inputKey, typeId); } public short getTypeId() { return typeId; } public Text getText() { return rawKey; } public boolean isNumberFamily() { if (typeId == TypeFlag.NONE_NUMERIC_TYPE.ordinal()) return false; return true; } public boolean isIntegerFamily() { return (typeId == TypeFlag.INTEGER_FAMILY_TYPE.ordinal()); } public byte getTypeIdByDatatype(DataType type) { if (!type.isNumberFamily()) { return (byte) TypeFlag.NONE_NUMERIC_TYPE.ordinal(); } else if (type.isIntegerFamily()) { return (byte) TypeFlag.INTEGER_FAMILY_TYPE.ordinal(); } else { return (byte) TypeFlag.DOUBLE_FAMILY_TYPE.ordinal(); } } public void setTypeId(byte typeId) { this.typeId = typeId; } }