myBatis执行流程全解析

概要：1. 执行流程解析2. myBatis插件开发一、执行流程解析配置文件解析 configuration：讲解解析流程之前先回顾一下myBatis 中配置文件的结构：mybatis-config.xml mybatis-mapper.xml 配置文件的解析流程即是将上述XML描述元素转换成对应的JAVA对像过程，其最终转换对像及其关系如下图：配置元素解析构建器org.apache.ibatis.builder.xml.XMLConfigBuilderorg.apache.ibatis.builder.xml.XMLMapperBuilder org.apache.ibatis.builder.xml.XMLStatementBuilder org.apache.ibatis.builder.SqlSourceBuilder org.apache.ibatis.scripting.xmltags.XMLScriptBuilderorg.apache.ibatis.builder.annotation.MapperAnnotationBuildersql statement 构建流程源码：org.apache.ibatis.session.SqlSessionFactoryBuilder#build()/1.Config.xml 文件解析org.apache.ibatis.builder.xml.XMLConfigBuilder#parse() org.apache.ibatis.builder.xml.XMLConfigBuilder#parseConfiguration() org.apache.ibatis.builder.xml.XMLConfigBuilder#mapperElement()/ 2.Mapper.xml 文件解析 org.apache.ibatis.builder.xml.XMLMapperBuilder#parse() org.apache.ibatis.builder.xml.XMLMapperBuilder#configurationElement() org.apache.ibatis.builder.xml.XMLMapperBuilder#buildStatementFromContext()/3.Statemen sql块解析 org.apache.ibatis.builder.xml.XMLStatementBuilder#parseStatementNode org.apache.ibatis.builder.MapperBuilderAssistant#addMappedStatement()/ 4.动态SQL脚本解析org.apache.ibatis.scripting.xmltags.XMLLanguageDriver#createSqlSource()org.apache.ibatis.scripting.xmltags.XMLScriptBuilder#parseScriptNode()org.apache.ibatis.scripting.xmltags.XMLScriptBuilder#parseDynamicTags()会话创建 SqlSession首先我们还是先来了解一下会话对像的组成结构如下图：会话构建源码解析:org.apache.ibatis.session.defaults.DefaultSqlSessionFactory#openSession(boolean)org.apache.ibatis.session.defaults.DefaultSqlSessionFactory#openSessionFromDataSourceorg.apache.ibatis.transaction.jdbc.JdbcTransactionFactory#newTransaction()org.apache.ibatis.session.Configuration#newExecutor()org.apache.ibatis.executor.SimpleExecutor#SimpleExecutororg.apache.ibatis.executor.CachingExecutor#CachingExecutor /执行器插件包装org.apache.ibatis.plugin.InterceptorChain#pluginAll(executor)org.apache.ibatis.session.defaults.DefaultSqlSession#DefaultSqlSession()方法执行 StatementHandlerStatementHandler 源码解析org.apache.ibatis.session.defaults.DefaultSqlSession#selectList()org.apache.ibatis.executor.CachingExecutor#query() org.apache.ibatis.executor.BaseExecutor#query() org.apache.ibatis.executor.BaseExecutor#queryFromDatabaseorg.apache.ibatis.session.Configuration#newStatementHandlerorg.apache.ibatis.executor.statement.BaseStatementHandler#BaseStatementHandlerorg.apache.ibatis.session.Configuration#newParameterHandlerorg.apache.ibatis.plugin.InterceptorChain#pluginAll(parameterHandler)org.apache.ibatis.session.Configuration#newResultSetHandlerorg.apache.ibatis.plugin.InterceptorChain#pluginAll(resultSetHandler)org.apache.ibatis.plugin.InterceptorChain#pluginAll(statementHandler)org.apache.ibatis.executor.BaseExecutor#getConnectionorg.apache.ibatis.executor.statement.PreparedStatementHandler#instantiateStatementorg.apache.ibatis.executor.statement.PreparedStatementHandler#parameterizeorg.apache.ibatis.scripting.defaults.DefaultParameterHandler#setParametersorg.apache.ibatis.type.BaseTypeHandler#setParameterorg.apache.ibatis.type.UnknownTypeHandler#setNonNullParameterorg.apache.ibatis.type.IntegerTypeHandler#setNonNullParameterMapper接口实例构建二、myBatis插件开发插件的四大扩展点1. Executor2. StatementHandler3. ParameterHandler4. ResultSetHandler分页插件实现：用户在接口中声明Page 对像实现后，由插件实现自动分页。使用示例如下：public class Page implements java.io.Serializable private int szie; / 每页大 private int number; / 当前页码page参数声明Select(select * from user)List selectByPage(String name, Page page