mybatis源码-创建工厂

构造一个工厂：

package com.laoxu.mybatis.executor;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class start {

    public static void main(String[] args) throws IOException {
        // user.dir指定了当前的路径
        String userDir = System.getProperty("user.dir");
        System.out.println(userDir);
        // 获取类路径
        String classPath = start.class.getResource("/").getPath();
        System.out.println(classPath);
        // 根据当前类路径下的相对路径 (classPath + {path})
        String resource = "mapper/mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }

}

读取核心配置文件mybatis-config.xml作为流进行创建工厂SqlSessionFactory

创建工厂构造器，返回一个默认的工厂。

/**
 *    Copyright 2009-2019 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.session;

import org.apache.ibatis.session.defaults.DefaultSqlSessionFactory;

import java.io.InputStream;
import java.util.Properties;

/**
 *构建{@link SqlSession}实例。
 *
 * @作者克林顿·贝京
 */
public class SqlSessionFactoryBuilder {

  public SqlSessionFactory build(InputStream inputStream) {
    return build(inputStream, null, null);
  }

  public SqlSessionFactory build(InputStream inputStream, String environment, Properties properties) {
    return new DefaultSqlSessionFactory();
  }

}

默认工厂类实现工厂接口：

/**
 *    Copyright 2009-2019 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.session.defaults;

import org.apache.ibatis.session.SqlSessionFactory;

/**
 * @作者克林顿·贝京
 */
public class DefaultSqlSessionFactory implements SqlSessionFactory {


}

/**
 *    Copyright 2009-2019 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.session;

/**
 *从一个连接或数据源创建一个{@link SqlSession}
 *
 * @作者克林顿·贝京
 */
public interface SqlSessionFactory {


}