看看mybatis 源代码
private class SqlSessionInterceptor implements InvocationHandler { public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { final SqlSession sqlSession = SqlSessionManager.this.localSqlSession.get(); if (sqlSession != null) { try { return method.invoke(sqlSession, args); } catch (Throwable t) { throw ExceptionUtil.unwrapThrowable(t); } } else { final SqlSession autoSqlSession = openSession(); try { final Object result = method.invoke(autoSqlSession, args); autoSqlSession.commit(); return result; } catch (Throwable t) { autoSqlSession.rollback(); throw ExceptionUtil.unwrapThrowable(t); } finally { autoSqlSession.close(); } } } }

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private SqlSessionManager(SqlSessionFactory sqlSessionFactory) { this.sqlSessionFactory = sqlSessionFactory; this.sqlSessionProxy = (SqlSession) Proxy.newProxyInstance( SqlSessionFactory.class.getClassLoader(), new Class[]{SqlSession.class}, new SqlSessionInterceptor()); }

?由上可以看出SqlSessionInterceptor代理类代理的接口为SqlSession.

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所以说SqlSessionFactory 为线程安全的,SqlSession为线程非安全性的类,但是控制事务的执行.