Mybatis执行Executor（一）

在DefaultSqlSession中我们可以看到一系列的增删改查操作的其实都是在调用Executor的接口，Mybatis对外统一提供了一个操作接口类Executor，提供的接口方法有update、query、flushStatements、commit、rollback等接口函数，源码如下：

/**
* @author Clinton Begin
*/
public interface Executor {

ResultHandler NO_RESULT_HANDLER = null;

/* 更新操作**/
int update(MappedStatement ms, Object parameter) throws SQLException;

/* 查询操作*/
<E> List<E> query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler, CacheKey cacheKey, BoundSql boundSql) throws SQLException;

<E> List<E> query(MappedStatement ms, Object parameter, RowBounds rowBounds, ResultHandler resultHandler) throws SQLException;

/* 更新statement操作*/
List<BatchResult> flushStatements() throws SQLException;
/*提交操作*/
void commit(boolean required) throws SQLException;
/*事务回滚操作*/
void rollback(boolean required) throws SQLException;
/*缓存key操作*/
CacheKey createCacheKey(MappedStatement ms, Object parameterObject, RowBounds rowBounds, BoundSql boundSql);
/*是否开启缓存*/
boolean isCached(MappedStatement ms, CacheKey key);
/*清除本地缓存操作*/
void clearLocalCache();
/*推迟加载操作*/
void deferLoad(MappedStatement ms, MetaObject resultObject, String property, CacheKey key, Class<?> targetType);
/*获取事务*/
Transaction getTransaction();

/*关闭连接*/
void close(boolean forceRollback);

boolean isClosed();

void setExecutorWrapper(Executor executor);

}

Executor接口只是简单 的定义了一些基本的操作接口，具体实现类有抽象类BaseExecutor、实现类CachingExecutor、实现类BatchExecutor、实现类ReuseExecutor和实现类SimpleExecutor，这些实现类的具体操作我们在接下来的博客中会一步一步进行分析，如下图所示：