UnpooledDataSourceFactory.java

/*
 *    Copyright 2009-2012 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.datasource.unpooled;

import java.util.Properties;

import javax.sql.DataSource;

import org.apache.ibatis.datasource.DataSourceException;
import org.apache.ibatis.datasource.DataSourceFactory;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;

/**
 * @author Clinton Begin
 */
/**
 * 没有池化的数据源工厂
 */
public class UnpooledDataSourceFactory implements DataSourceFactory {

  private static final String DRIVER_PROPERTY_PREFIX = "driver.";
  private static final int DRIVER_PROPERTY_PREFIX_LENGTH = DRIVER_PROPERTY_PREFIX.length();

  protected DataSource dataSource;

  public UnpooledDataSourceFactory() {
    this.dataSource = new UnpooledDataSource();
  }

  @Override
  public void setProperties(Properties properties) {
    Properties driverProperties = new Properties();
    MetaObject metaDataSource = SystemMetaObject.forObject(dataSource);
    for (Object key : properties.keySet()) {
      String propertyName = (String) key;
      //作为可选项,你可以传递数据库驱动的属性。要这样做,属性的前缀是以“driver.”开 头的,例如
      //driver.encoding=UTF8
      if (propertyName.startsWith(DRIVER_PROPERTY_PREFIX)) {
        String value = properties.getProperty(propertyName);
        driverProperties.setProperty(propertyName.substring(DRIVER_PROPERTY_PREFIX_LENGTH), value);
      } else if (metaDataSource.hasSetter(propertyName)) {
    	  //如果UnpooledDataSource有相应的setter函数，则设置它
        String value = (String) properties.get(propertyName);
        Object convertedValue = convertValue(metaDataSource, propertyName, value);
        metaDataSource.setValue(propertyName, convertedValue);
      } else {
        throw new DataSourceException("Unknown DataSource property: " + propertyName);
      }
    }
    if (driverProperties.size() > 0) {
      metaDataSource.setValue("driverProperties", driverProperties);
    }
  }

  @Override
  public DataSource getDataSource() {
    return dataSource;
  }

  //根据setter的类型,将配置文件中的值强转成相应的类型
  private Object convertValue(MetaObject metaDataSource, String propertyName, String value) {
    Object convertedValue = value;
    Class<?> targetType = metaDataSource.getSetterType(propertyName);
    if (targetType == Integer.class || targetType == int.class) {
      convertedValue = Integer.valueOf(value);
    } else if (targetType == Long.class || targetType == long.class) {
      convertedValue = Long.valueOf(value);
    } else if (targetType == Boolean.class || targetType == boolean.class) {
      convertedValue = Boolean.valueOf(value);
    }
    return convertedValue;
  }

}