Mybatis-LanguageDriver源码解析

Mybatis3.5.1源码分析

1. Mybatis-SqlSessionFactoryBuilder，XMLConfigBuilder，XPathParser源码解析
2. Mybatis-Configuration源码解析
3. Mybatis-事务对象源码解析
4. Mybatis-数据源源码解析
5. Mybatis缓存策略源码解析
6. Mybatis-DatabaseIdProvider源码解析
7. Mybatis-TypeHandler源码解析
8. Mybatis-Reflector源码解析
9. Mybatis-ObjectFactory，ObjectWrapperFactory源码分析
10. Mybatis-Mapper各类标签封装类源码解析
11. Mybatis-XMLMapperBuilder,XMLStatmentBuilder源码分析
12. Mybatis-MapperAnnotationBuilder源码分析
13. [Mybatis-MetaObject,MetaClass源码解析]https://www.jianshu.com/p/f51fa552f30a)
14. Mybatis-LanguageDriver源码解析
15. Mybatis-SqlSource源码解析
16. Mybatis-SqlNode源码解析
17. Mybatis-KeyGenerator源码解析
18. Mybatis-Executor源码解析
19. Mybatis-ParameterHandler源码解析
20. Mybatis-StatementHandler源码解析
21. Mybatis-DefaultResultSetHandler(一)源码解析
22. Mybatis-DefaultResultSetHandler(二)源码解析
23. Mybatis-ResultHandler,Cursor,RowBounds 源码分析
24. Mybatis-MapperProxy源码解析
25. Mybatis-SqlSession源码解析
26. Mybatis-Interceptor源码解析

LanguageDriver

/**
 *    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.scripting;

import org.apache.ibatis.executor.parameter.ParameterHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource;
import org.apache.ibatis.parsing.XNode;
import org.apache.ibatis.scripting.defaults.DefaultParameterHandler;
import org.apache.ibatis.session.Configuration;

/**
 * 语言驱动
 */
public interface LanguageDriver {

  /**
   * Creates a {@link ParameterHandler} that passes the actual parameters to the the JDBC statement.
   * 创建 {@link ParameterHandler} 通过JDBC的实际参数
   * @param mappedStatement The mapped statement that is being executed 映射的正在执行语句
   * @param parameterObject The input parameter object (can be null) 输入的参数对象（可以为空）
   * @param boundSql The resulting SQL once the dynamic language has been executed. 生成的SQL，一旦动态语言被执行
   * @return
   * @author Frank D. Martinez [mnesarco]
   * @see DefaultParameterHandler
   */
  ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql);

  /**
   * Creates an {@link SqlSource} that will hold the statement read from a mapper xml file.
   * It is called during startup, when the mapped statement is read from a class or an xml file.
   * 创建一个{@link SqlSource} 读取映射XML文件
   * @param configuration The MyBatis configuration MyBatis配置
   * @param script XNode parsed from a XML file
   * @param parameterType input parameter type got from a mapper method or specified in the parameterType xml attribute. Can be null.
   *                      输入参数类型从一个xml类型映射器参数中指定的方法或属性。可以为空。;
   * @return
   */
  SqlSource createSqlSource(Configuration configuration, XNode script, Class parameterType);

  /**
   * Creates an {@link SqlSource} that will hold the statement read from an annotation.
   * It is called during startup, when the mapped statement is read from a class or an xml file.
   * 创建一个{@link SqlSource} 从一个字解里，它在启动期间,当映射语句从一个类或读取一个xml文件被调用。;
   * @param configuration The MyBatis configuration
   * @param script The content of the annotation
   * @param parameterType input parameter type got from a mapper method or specified in the parameterType xml attribute. Can be null.
   *                      输入参数类型从一个xml类型映射器参数中指定的方法或属性。可以为空。;
   * @return
   */
  SqlSource createSqlSource(Configuration configuration, String script, Class parameterType);

}

XMLLanguageDriver

/**
 *    Copyright 2009-2015 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.scripting.xmltags;

import org.apache.ibatis.builder.xml.XMLMapperEntityResolver;
import org.apache.ibatis.executor.parameter.ParameterHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource;
import org.apache.ibatis.parsing.PropertyParser;
import org.apache.ibatis.parsing.XNode;
import org.apache.ibatis.parsing.XPathParser;
import org.apache.ibatis.scripting.LanguageDriver;
import org.apache.ibatis.scripting.defaults.DefaultParameterHandler;
import org.apache.ibatis.scripting.defaults.RawSqlSource;
import org.apache.ibatis.session.Configuration;

/**
 * XML语言驱动
 * 

 *     Mybatis默认XML驱动类为XMLLanguageDriver，其主要作用于解析select|update|insert|delete节点为完整的SQL语句。
 * 
 * @author Eduardo Macarron
 */
public class XMLLanguageDriver implements LanguageDriver {

  @Override
  public ParameterHandler createParameterHandler(MappedStatement mappedStatement, Object parameterObject, BoundSql boundSql) {
    return new DefaultParameterHandler(mappedStatement, parameterObject, boundSql);
  }

  @Override
  public SqlSource createSqlSource(Configuration configuration, XNode script, Class parameterType) {
    XMLScriptBuilder builder = new XMLScriptBuilder(configuration, script, parameterType);
    /***
     *  当sql中包含有${}时，就认为是动态SQL
     *       或者 当DML标签存在动态SQL标签名，如<if>,<trim>等，就认为是动态SQL
     *  ，如果是动态返回 {@link DynamicSqlSource} ，否则 {@link RawSqlSource}
     */
    return builder.parseScriptNode();
  }

  @Override
  public SqlSource createSqlSource(Configuration configuration, String script, Class parameterType) {
    // issue #3 此处兼容XML方式的解析，条件以