EgovCompositeCursorReader.java

/*
 * Copyright 2006-2007 the original author or authors.
 *
 * Licensed 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 egovframework.rte.bat.core.item.composite.reader;

import java.util.List;

import org.springframework.batch.item.ExecutionContext;
import org.springframework.batch.item.ItemStream;
import org.springframework.batch.item.ItemStreamException;
import org.springframework.batch.item.ItemStreamReader;
import org.springframework.batch.item.NonTransientResourceException;
import org.springframework.batch.item.ParseException;
import org.springframework.batch.item.UnexpectedInputException;
import org.springframework.batch.item.database.AbstractCursorItemReader;

import egovframework.rte.bat.core.item.composite.EgovItemsMapper;

/**
 * CompositeCursorReader를 통해 ItemReaderList에 등록된 DB아이템을 읽어들임 
 * 
 * @author 배치실행개발팀
 * @since 2012. 07.30
 * @version 1.0
 * @see
 * 
 *      <pre>
 * << 개정이력(Modification Information) >>
 *   
 *   수정일               수정자               수정내용
 *  -------      --------     ---------------------------
 *  2012. 10.20  배치실행개발팀    최초 생성
 * 
 * </pre>
 */
public class EgovCompositeCursorReader<T> implements ItemStreamReader<T> {
	private List<AbstractCursorItemReader<?>> itemReaderList;
	private EgovItemsMapper<T> itemsMapper;
	private String returnType;
	public T read() throws Exception, UnexpectedInputException, ParseException,
			NonTransientResourceException {
		Object[] items = new Object[itemReaderList.size()];
		
		int count = 0;
		int flagCount = 0;
		if(returnType.toUpperCase().equals("READER")){
			
			for (AbstractCursorItemReader<?> itemReader : itemReaderList) {
				items[count] = itemReader;
				count++;
			}
		} else {
			for (AbstractCursorItemReader<?> itemReader : itemReaderList) {
				Object o = null;
				
				if ((o = itemReader.read())== null) {
					flagCount = flagCount + 1;
				} else {
					items[count] = o;
				}
				count++;
				
				if(flagCount == itemReaderList.size()) {
					return null;
				}
			}
		}
		return itemsMapper.mapItems(items);
	}

	/**
	 * 변경된 사항을 등록된 모든 Reader에 update함 
	 * 
	 * @see org.springframework.batch.item.ItemStream#update(ExecutionContext)
	 */
	public void update(ExecutionContext executionContext) {
		for (ItemStream itemStream : itemReaderList) {
			itemStream.update(executionContext);
		}
	}

	/**
	 * 모든 Reader에 close를 호출함 
	 * 
	 * @throws ItemStreamException
	 */
	public void close() throws ItemStreamException {
		for (ItemStream itemStream : itemReaderList) {
			itemStream.close();
		}
	}

	/**
	 * 모든 Reader에 open을 호출함 
	 * 
	 * @throws ItemStreamException
	 */
	public void open(ExecutionContext executionContext)
			throws ItemStreamException {
		for (ItemStream itemStream : itemReaderList) {
			itemStream.open(executionContext);
		}
	}

	/**
	 * 설정파일에 세팅한 값을 ItemMapper에 Setting 
	 * 
	 * @param mapper
	 */
	public void setItemsMapper(EgovItemsMapper<T> mapper) {
		this.itemsMapper = mapper;
	}

	/**
	 * 설정파일에서 ItemReaderList에 등록한 값을  Setting
	 * 
	 * @param itemReaderList
	 */
	public void setItemReaderList(List<AbstractCursorItemReader<?>> itemReaderList) {
		this.itemReaderList = itemReaderList;
	}

	/**
	 * 설정파일에서  등록한 returnType을 Setting 
	 * 
	 * @param returnType
	 */
	public void setReturnType(String returnType) {
		this.returnType = returnType;
	}
	
}