谁能读懂下面的代码
public PaginatedList queryForPaginatedList(
final String statementName, final Object parameterObject, final int pageSize)
throws DataAccessException {
// Throw exception if lazy loading will not work.
if (this.sqlMapClient instanceof ExtendedSqlMapClient &&
((ExtendedSqlMapClient) this.sqlMapClient).getDelegate().getTxManager() == null) {
throw new InvalidDataAccessApiUsageException(
"SqlMapClient needs to have DataSource to allow for lazy loading" +
" - specify SqlMapClientFactoryBean's 'dataSource' property");
}
return (PaginatedList) execute(new SqlMapClientCallback() {
public Object doInSqlMapClient(SqlMapExecutor executor) throws SQLException {
return executor.queryForPaginatedList(statementName, parameterObject, pageSize);
}
});
}
这段代码来源于org.springframework.orm.ibatis的SqlMapClientTemplate这个类
请问:
SqlMapExecutor executor这个对象真正是什么了?如果它还没有被实例化对某对象,下面的return executor.queryForPaginatedList(statementName, parameterObject, pageSize);一定是有错误的,但是这个代码又是对的。
所以,高手们,请问executor在哪里被实例化成什么对象了?