| /* |
| * 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.tutorial; |
| |
| import java.io.IOException; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| import java.util.List; |
| import java.util.ArrayList; |
| |
| import org.apache.pig.FilterFunc; |
| import org.apache.pig.FuncSpec; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.impl.logicalLayer.schema.Schema; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| |
| /** |
| * This function removes search queries that are URLs (as defined by _urlPattern). |
| * This function also removes empty queries. |
| */ |
| public class NonURLDetector extends FilterFunc { |
| |
| private Pattern _urlPattern = Pattern.compile("^[\"]?(http[:|;])|(https[:|;])|(www\\.)"); |
| |
| public Boolean exec(Tuple arg0) throws IOException { |
| if (arg0 == null || arg0.size() == 0) |
| return false; |
| |
| String query; |
| try{ |
| query = (String)arg0.get(0); |
| if(query == null) |
| return false; |
| query = query.trim(); |
| }catch(Exception e){ |
| System.err.println("NonURLDetector: failed to process input; error - " + e.getMessage()); |
| return false; |
| } |
| |
| if (query.equals("")) { |
| return false; |
| } |
| Matcher m = _urlPattern.matcher(query); |
| if (m.find()) { |
| return false; |
| } |
| return true; |
| } |
| |
| /* (non-Javadoc) |
| * @see org.apache.pig.EvalFunc#getArgToFuncMapping() |
| * This is needed to make sure that both bytearrays and chararrays can be passed as arguments |
| */ |
| @Override |
| public List<FuncSpec> getArgToFuncMapping() throws FrontendException { |
| List<FuncSpec> funcList = new ArrayList<FuncSpec>(); |
| funcList.add(new FuncSpec(this.getClass().getName(), new Schema(new Schema.FieldSchema(null, DataType.CHARARRAY)))); |
| |
| return funcList; |
| } |
| |
| } |