Transaction
类图
接口定义
public interface Transaction { Connection getConnection() throws SQLException; void commit() throws SQLException; void rollback() throws SQLException; void close() throws SQLException; Integer getTimeout() throws SQLException; }
ManagedTransaction
说明
含义为托管事务,空壳事务管理器,皮包公司。仅是提醒用户,在其它环境中应用时,把事务托管给其它框架,比如托管给Spring,让Spring去管理事务。
部分源码
public class ManagedTransaction implements Transaction { private static final Log log = LogFactory.getLog(org.apache.ibatis.transaction.managed.ManagedTransaction.class); private DataSource dataSource; private TransactionIsolationLevel level; private Connection connection; private boolean closeConnection; public void commit() throws SQLException { } public void rollback() throws SQLException { } }
可以看到commit和rollback都是空实现
JDBCTransaction
部分源码
public class JdbcTransaction implements Transaction { private static final Log log = LogFactory.getLog(JdbcTransaction.class); protected Connection connection; protected DataSource dataSource; protected TransactionIsolationLevel level; protected boolean autoCommmit; public JdbcTransaction(DataSource ds, TransactionIsolationLevel desiredLevel, boolean desiredAutoCommit) { this.dataSource = ds; this.level = desiredLevel; this.autoCommmit = desiredAutoCommit; } public JdbcTransaction(Connection connection) { this.connection = connection; } public Connection getConnection() throws SQLException { if (this.connection == null) { this.openConnection(); } return this.connection; } /** * 提交 * @throws SQLException */ public void commit() throws SQLException { if (this.connection != null && !this.connection.getAutoCommit()) { if (log.isDebugEnabled()) { log.debug("Committing JDBC Connection [" + this.connection + "]"); } this.connection.commit(); } } /** * 回滚 * @throws SQLException */ public void rollback() throws SQLException { if (this.connection != null && !this.connection.getAutoCommit()) { if (log.isDebugEnabled()) { log.debug("Rolling back JDBC Connection [" + this.connection + "]"); } this.connection.rollback(); } } /** * 关闭连接 * @throws SQLException */ public void close() throws SQLException { if (this.connection != null) { //因为close是将连接放回连接池 所以重置事物AutoCommit属性 this.resetAutoCommit(); if (log.isDebugEnabled()) { log.debug("Closing JDBC Connection [" + this.connection + "]"); } this.connection.close(); } } /** * 重置AutoCommit属性 */ protected void resetAutoCommit() { try { if (!this.connection.getAutoCommit()) { if (log.isDebugEnabled()) { log.debug("Resetting autocommit to true on JDBC Connection [" + this.connection + "]"); } this.connection.setAutoCommit(true); } } catch (SQLException var2) { if (log.isDebugEnabled()) { log.debug("Error resetting autocommit to true before closing the connection. Cause: " + var2); } } } }
TransactionFactory
类图
2个工厂创建对应的事物管理器(这里应用的是抽象工厂模式) 内部知识检查的创建对应的管理器
xml设置对应的事物管理
<!-- 对事务的管理和连接池的配置 --> <environments default="development"> <environment id="development"> <transactionManager type="JDBC" /><!--设置对应的事物工厂--> <!--UNPOOLED 非连接池 POOLED mybatis提供的POOLED连接池 JNDI mybtais提供的JNDIfacotory获取数据源 根据配置找到对应的工厂 创建对应的数据源 可以直接配置工厂 需要实现UnpooledDataSourceFactory --> <dataSource type="com.liqiang.datasource.C3P0DataSourceFactory"> <property name="driverClass" value="com.mysql.jdbc.Driver" /> <property name="jdbcUrl" value="jdbc:mysql://ip:port/ocms-product?characterEncoding=utf-8"/> <property name="user" value="devops" /> <property name="password" value="Devops@123" /> </dataSource> </environment> </environments>