SqlSessionDaoSupport.java

/**
 *    Copyright 2010-2017 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.mybatis.spring.support;

import static org.springframework.util.Assert.notNull;

import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionTemplate;
import org.springframework.dao.support.DaoSupport;

/**
 * Convenient super class for MyBatis SqlSession data access objects.
 * It gives you access to the template which can then be used to execute SQL methods.
 * <p>
 * This class needs a SqlSessionTemplate or a SqlSessionFactory.
 * If both are set the SqlSessionFactory will be ignored.
 * <p>
 * 
 * @author Putthiphong Boonphong
 * @author Eduardo Macarron
 *
 * @see #setSqlSessionFactory
 * @see #setSqlSessionTemplate
 * @see SqlSessionTemplate
 */
public abstract class SqlSessionDaoSupport extends DaoSupport {

  private SqlSessionTemplate sqlSessionTemplate;

  /**
   * Set MyBatis SqlSessionFactory to be used by this DAO.
   * Will automatically create SqlSessionTemplate for the given SqlSessionFactory.
   */
  public void setSqlSessionFactory(SqlSessionFactory sqlSessionFactory) {
    if (this.sqlSessionTemplate == null || sqlSessionFactory != this.sqlSessionTemplate.getSqlSessionFactory()) {
      this.sqlSessionTemplate = createSqlSessionTemplate(sqlSessionFactory);
    }
  }

  /**
   * Create a SqlSessionTemplate for the given SqlSessionFactory.
   * Only invoked if populating the DAO with a SqlSessionFactory reference!
   * <p>Can be overridden in subclasses to provide a SqlSessionTemplate instance
   * with different configuration, or a custom SqlSessionTemplate subclass.
   * @param sqlSessionFactory the MyBatis SqlSessionFactory to create a SqlSessionTemplate for
   * @return the new SqlSessionTemplate instance
   * @see #setSqlSessionFactory
   */
  @SuppressWarnings("WeakerAccess")
  protected SqlSessionTemplate createSqlSessionTemplate(SqlSessionFactory sqlSessionFactory) {
    return new SqlSessionTemplate(sqlSessionFactory);
  }

  /**
   * Return the MyBatis SqlSessionFactory used by this DAO.
   */
  public final SqlSessionFactory getSqlSessionFactory() {
    return (this.sqlSessionTemplate != null ? this.sqlSessionTemplate.getSqlSessionFactory() : null);
  }


  /**
   * Set the SqlSessionTemplate for this DAO explicitly,
   * as an alternative to specifying a SqlSessionFactory.
   * @see #setSqlSessionFactory
   */
  public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
    this.sqlSessionTemplate = sqlSessionTemplate;
  }

  /**
   * Users should use this method to get a SqlSession to call its statement methods
   * This is SqlSession is managed by spring. Users should not commit/rollback/close it
   * because it will be automatically done.
   *
   * @return Spring managed thread safe SqlSession
   */
  public SqlSession getSqlSession() {
    return this.sqlSessionTemplate;
  }

  /**
   * Return the SqlSessionTemplate for this DAO,
   * pre-initialized with the SessionFactory or set explicitly.
   * <p><b>Note: The returned SqlSessionTemplate is a shared instance.</b>
   * You may introspect its configuration, but not modify the configuration
   * (other than from within an {@link #initDao} implementation).
   * Consider creating a custom SqlSessionTemplate instance via
   * {@code new SqlSessionTemplate(getSqlSessionFactory())}, in which case
   * you're allowed to customize the settings on the resulting instance.
   */
  public SqlSessionTemplate getSqlSessionTemplate() {
    return this.sqlSessionTemplate;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  protected void checkDaoConfig() {
    notNull(this.sqlSessionTemplate, "Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required");
  }

}