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.hadoop.hive.ql.udf; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.hive.ql.exec.UDF; public class UDFToString extends UDF { private static Log LOG = LogFactory.getLog(UDFToString.class.getName()); public UDFToString() { } public String evaluate(Boolean i) { if (i == null) { return null; } else { return i.booleanValue() ? "TRUE" : "FALSE"; } } public String evaluate(Byte i) { if (i == null) { return null; } else { return i.toString(); } } public String evaluate(Integer i) { if (i == null) { return null; } else { return i.toString(); } } public String evaluate(Long i) { if (i == null) { return null; } else { return i.toString(); } } public String evaluate(Float i) { if (i == null) { return null; } else { return i.toString(); } } public String evaluate(Double i) { if (i == null) { return null; } else { return i.toString(); } } public String evaluate(java.sql.Date i) { if (i == null) { return null; } else { return i.toString(); } } }