| /** |
| * 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.builtin; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.FuncSpec; |
| import org.apache.pig.PigWarning; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.backend.executionengine.ExecException; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| |
| /** |
| * Pig UDF to test input <code>tuple.get(0)</code> against <code>tuple.get(1)</code> |
| * to determine if the first argument starts with the string in the second. |
| */ |
| public class STARTSWITH extends EvalFunc<Boolean> { |
| @Override |
| public Boolean exec(Tuple tuple) { |
| if (tuple == null || tuple.size() != 2) { |
| warn("invalid number of arguments to STARTSWITH", PigWarning.UDF_WARNING_1); |
| return null; |
| } |
| String argument = null; |
| String testAgainst = null; |
| try { |
| argument = (String) tuple.get(0); |
| testAgainst = (String) tuple.get(1); |
| return argument.startsWith(testAgainst); |
| } catch (NullPointerException npe) { |
| warn(npe.toString(), PigWarning.UDF_WARNING_2); |
| return null; |
| } catch (ClassCastException cce) { |
| warn(cce.toString(), PigWarning.UDF_WARNING_3); |
| return null; |
| } catch (ExecException ee) { |
| warn(ee.toString(), PigWarning.UDF_WARNING_4); |
| return null; |
| } |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(null, DataType.BOOLEAN)); |
| } |
| |
| @Override |
| public List<FuncSpec> getArgToFuncMapping() throws FrontendException { |
| List<FuncSpec> funcList = new ArrayList<FuncSpec>(); |
| Schema s = new Schema(); |
| s.add(new Schema.FieldSchema(null, DataType.CHARARRAY)); |
| s.add(new Schema.FieldSchema(null, DataType.CHARARRAY)); |
| funcList.add(new FuncSpec(this.getClass().getName(), s)); |
| return funcList; |
| } |
| |
| @Override |
| public boolean allowCompileTimeCalculation() { |
| return true; |
| } |
| } |