| /* |
| * 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.pig.piggybank.evaluation; |
| |
| import java.io.IOException; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.PigWarning; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| /** |
| * This UDF is used to check whether the String input is a Double. |
| * Note this function checks for Double range. |
| * If range is not important, use IsNumeric instead if you would like to check if a String is numeric. |
| * Also IsNumeric performs slightly better compared to this function. |
| */ |
| |
| public class IsDouble extends EvalFunc<Boolean> { |
| @Override |
| public Boolean exec(Tuple input) throws IOException { |
| if (input == null || input.size() == 0) return false; |
| try { |
| String str = (String)input.get(0); |
| if (str == null || str.length() == 0) return false; |
| Double.parseDouble(str); |
| } catch (NumberFormatException nfe) { |
| return false; |
| } catch (ClassCastException e) { |
| warn("Unable to cast input "+input.get(0)+" of class "+ |
| input.get(0).getClass()+" to String", PigWarning.UDF_WARNING_1); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(null, DataType.BOOLEAN)); |
| } |
| } |