JDBC core API supports local transactions. Connection Pooling through DataSource option provides Distributed Transactions support. Connection Interface handles Transactions. Transaction is a set of one or more SQL grouped to do a logical unit of work.ACID Properties
JDBC Isolation Levels
Dirty Reads occur when transaction reads uncommitted data.
Repeatable Read occur when one transaction reads committed data.Other Transaction updates the same data. First transaction Reads again in the same Transaction, gets inconsistent data, because first read data and second read data differs in the same transaction itself
Phantom read occurs, when first transaction Reads filtered data with where class, second transaction updates the same data.