| /* |
| * 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.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.pig.FuncSpec; |
| import org.apache.pig.EvalFunc; |
| import org.apache.pig.PigWarning; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| |
| /** |
| * string.INSTR implements eval function to search for the last occurrence of a string |
| * Returns null on error |
| * Example: |
| * <code> |
| * A = load 'mydata' as (name); |
| * B = foreach A generate LASTINDEXOF(name, ","); |
| * </code> |
| */ |
| public class LAST_INDEX_OF extends EvalFunc<Integer> { |
| |
| /** |
| * Finds the last location of a substring in a given string. |
| * @param input tuple:<ol> |
| * <li>the string to process |
| * <li>the substring to find |
| * </ol> |
| * @exception java.io.IOException |
| * @return last location of substring, or null in case of processing errors. |
| */ |
| @Override |
| public Integer exec(Tuple input) throws IOException { |
| if (input == null || input.size() < 2) |
| return null; |
| |
| try { |
| String str = (String)input.get(0); |
| String search = (String)input.get(1); |
| return str.lastIndexOf(search); |
| } catch(Exception e) { |
| warn("Failed to process input; error - " + e.getMessage(), PigWarning.UDF_WARNING_1); |
| return null; |
| } |
| } |
| |
| @Override |
| public Schema outputSchema(Schema input) { |
| return new Schema(new Schema.FieldSchema(null, DataType.INTEGER)); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.apache.pig.EvalFunc#getArgToFuncMapping() |
| */ |
| @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; |
| } |
| } |