| /* |
| * 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 if a String is numeric. Note this UDF is different |
| * from IsInt in 2 ways, 1. Does not check for Integer range 2. Runs faster as |
| * this UDF uses Regex match and not Integer.parseInt(String) |
| * |
| * This UDF is expected to perform slightly better than isInt, isLong, isFloat, |
| * isDouble. However, primary goal of this UDF is NOT performance but rather to |
| * check "numeric"-ness of a String. Use this UDF if you do not care for the |
| * type (int, long, float, double) and would just like to check if its numeric |
| * in nature. |
| * |
| * It does NOT check for Range of int, long, double, parse. This function will |
| * return true when the String is larger than the range of any numeric data type |
| * (int, long, double, float). Use specific functions (IsInt, IsFloat, IsLong, |
| * IsDouble) if range is important. |
| * |
| */ |
| public class IsNumeric 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; |
| |
| if (str.startsWith("-")) |
| str = str.substring(1); |
| |
| return str.matches("\\d+(\\.\\d+)?"); |
| |
| } 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; |
| } |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(null, DataType.BOOLEAN)); |
| } |
| } |