/*
* Copyright 2009-2013 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 org.apache.ibatis.executor.loader;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import org.apache.ibatis.cache.CacheKey;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.executor.ExecutorException;
import org.apache.ibatis.executor.ResultExtractor;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.reflection.factory.ObjectFactory;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.RowBounds;
import org.apache.ibatis.transaction.Transaction;
import org.apache.ibatis.transaction.TransactionFactory;
/**
* @author Clinton Begin
*/
public class ResultLoader {
protected final Configuration configuration;
protected final Executor executor;
protected final MappedStatement mappedStatement;
protected final Object parameterObject;
protected final Class<?> targetType;
protected final ObjectFactory objectFactory;
protected final CacheKey cacheKey;
protected final BoundSql boundSql;
protected final ResultExtractor resultExtractor;
protected final long creatorThreadId;
protected boolean loaded;
protected Object resultObject;
public ResultLoader(Configuration config, Executor executor, MappedStatement mappedStatement, Object parameterObject, Class<?> targetType, CacheKey cacheKey, BoundSql boundSql) {
this.configuration = config;
this.executor = executor;
this.mappedStatement = mappedStatement;
this.parameterObject = parameterObject;
this.targetType = targetType;
this.objectFactory = configuration.getObjectFactory();
this.cacheKey = cacheKey;
this.boundSql = boundSql;
this.resultExtractor = new ResultExtractor(configuration, objectFactory);
this.creatorThreadId = Thread.currentThread().getId();
}
public Object loadResult() throws SQLException {
List<Object> list = selectList();
resultObject = resultExtractor.extractObjectFromList(list, targetType);
return resultObject;
}
private <E> List<E> selectList() throws SQLException {
Executor localExecutor = executor;
if (Thread.currentThread().getId() != this.creatorThreadId || localExecutor.isClosed()) {
localExecutor = newExecutor();
}
try {
return localExecutor.<E> query(mappedStatement, parameterObject, RowBounds.DEFAULT, Executor.NO_RESULT_HANDLER, cacheKey, boundSql);
} finally {
if (localExecutor != executor) {
localExecutor.close(false);
}
}
}
private Executor newExecutor() {
final Environment environment = configuration.getEnvironment();
if (environment == null) {
throw new ExecutorException("ResultLoader could not load lazily. Environment was not configured.");
}
final DataSource ds = environment.getDataSource();
if (ds == null) {
throw new ExecutorException("ResultLoader could not load lazily. DataSource was not configured.");
}
final TransactionFactory transactionFactory = environment.getTransactionFactory();
final Transaction tx = transactionFactory.newTransaction(ds, null, false);
return configuration.newExecutor(tx, ExecutorType.SIMPLE);
}
public boolean wasNull() {
return resultObject == null;
}
}