| /** |
| * 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 com.datatorrent.contrib.util; |
| |
| import java.lang.reflect.Constructor; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * This is a copy from contrib, should be merged later. |
| * |
| */ |
| public class TupleGenerator<T> |
| { |
| private static final Logger logger = LoggerFactory.getLogger( TupleGenerator.class ); |
| |
| private volatile long rowId = 0; |
| private Constructor<T> constructor; |
| |
| private static Class<?>[] paramTypes = new Class<?>[]{ Long.class, long.class, Integer.class, int.class }; |
| |
| public TupleGenerator() |
| { |
| } |
| |
| public TupleGenerator( Class<T> tupleClass ) |
| { |
| useTupleClass( tupleClass ); |
| } |
| |
| public void useTupleClass( Class<T> tupleClass ) |
| { |
| for( Class<?> paramType : paramTypes ) |
| { |
| constructor = tryGetConstructor( tupleClass, paramType ); |
| if( constructor != null ) |
| break; |
| } |
| if( constructor == null ) |
| { |
| logger.error( "Not found proper constructor." ); |
| throw new RuntimeException( "Not found proper constructor." ); |
| } |
| } |
| |
| protected Constructor<T> tryGetConstructor( Class<T> tupleClass, Class<?> parameterType ) |
| { |
| try |
| { |
| return tupleClass.getConstructor( parameterType ); |
| } |
| catch( Exception e ) |
| { |
| return null; |
| } |
| } |
| |
| public void reset() |
| { |
| rowId = 0; |
| } |
| |
| public T getNextTuple() |
| { |
| if( constructor == null ) |
| throw new RuntimeException( "Not found proper constructor." ); |
| |
| long curRowId = ++rowId; |
| try |
| { |
| return constructor.newInstance( curRowId ); |
| } |
| catch( Exception e) |
| { |
| logger.error( "newInstance failed.", e ); |
| return null; |
| } |
| } |
| |
| } |