Mybatis事务（三）事务工厂

电玩女神 2022-02-24 12:24 285阅读 0赞

在前面一篇博客Mybatis事务（一）事务管理方式中我们提到，mybatis及spring提供了三个事务实现类：JdbcTransaction、ManagedTransaction和SpringManagedTransaction三个事务实现类，同时Mybatis也很友好的给我们提供了对应事务类的生成工厂。

TransactionFactory接口：提供的主要接口是newTransaction（），根据数据库连接Connection来创建事务，源码如下：

//事务工厂接口
    public interface TransactionFactory {
     
      /**
       * Sets transaction factory custom properties.
       * @param props
       */
      //配置工厂属性
      void setProperties(Properties props);
     
      /**
       * Creates a {@link Transaction} out of an existing connection.
       * @param conn Existing database connection
       * @return Transaction
       * @since 3.1.0
       */
      //通过Connection获得事务
      Transaction newTransaction(Connection conn);
      
      /**
       * Creates a {@link Transaction} out of a datasource.
       * @param dataSource DataSource to take the connection from
       * @param level Desired isolation level
       * @param autoCommit Desired autocommit
       * @return Transaction
       * @since 3.1.0
       */
      //通过数据库，事务等级及事务是否自动提交创建事务
      Transaction newTransaction(DataSource dataSource, TransactionIsolationLevel level, boolean autoCommit);
     
    }

JdbcTransactionFactory：创建JdbcTransaction事务，源码如下：

public class JdbcTransactionFactory implements TransactionFactory {
     
      @Override
      public void setProperties(Properties props) {
      }
     
      @Override
      public Transaction newTransaction(Connection conn) {
    	//创建JDBC事务
        return new JdbcTransaction(conn);
      }
     
      @Override
      public Transaction newTransaction(DataSource ds, TransactionIsolationLevel level, boolean autoCommit) {
        return new JdbcTransaction(ds, level, autoCommit);
      }
    }

ManagedTransactionFactory：创建ManagedTransaction事务，源码如下：

public class ManagedTransactionFactory implements TransactionFactory {
     
      private boolean closeConnection = true;
     
      @Override
      public void setProperties(Properties props) {
        if (props != null) {
          String closeConnectionProperty = props.getProperty("closeConnection");
          if (closeConnectionProperty != null) {
            closeConnection = Boolean.valueOf(closeConnectionProperty);
          }
        }
      }
     
      @Override
      public Transaction newTransaction(Connection conn) {
    	//创建MANAGED事务
        return new ManagedTransaction(conn, closeConnection);
      }
     
      @Override
      public Transaction newTransaction(DataSource ds, TransactionIsolationLevel level, boolean autoCommit) {
        // Silently ignores autocommit and isolation level, as managed transactions are entirely
        // controlled by an external manager.  It's silently ignored so that
        // code remains portable between managed and unmanaged configurations.
        return new ManagedTransaction(ds, level, closeConnection);
      }
    }

SpringManagedTransactionFactory：创建SpringManagedTransaction，源码如下：

public class SpringManagedTransactionFactory implements TransactionFactory {
     
      /**
       * {@inheritDoc}
       */
      @Override
      public Transaction newTransaction(DataSource dataSource, TransactionIsolationLevel level, boolean autoCommit) {
    	//spring 通过DataSource创建事务
        return new SpringManagedTransaction(dataSource);
      }
     
      /**
       * {@inheritDoc}
       */
      @Override
      public Transaction newTransaction(Connection conn) {
    	//无法通过connection创建事务
        throw new UnsupportedOperationException("New Spring transactions require a DataSource");
      }
     
      /**
       * {@inheritDoc}
       */
      @Override
      public void setProperties(Properties props) {
        // not needed in this version
      }
     
    }

Mybatis提供了简单有效的事务生产工厂

本文原文地址：[https://blog.csdn.net/qq924862077/article/details/52600152][https_blog.csdn.net_qq924862077_article_details_52600152]

[https_blog.csdn.net_qq924862077_article_details_52600152]: https://blog.csdn.net/qq924862077/article/details/52600152