Java 如何检查数据库是否可用，以及如何在sessionFactory=configuration.buildSessionFactory（serviceRegistry）之后运行查询

这是我初始化SessionFactory的代码

    configuration.setProperty("hibernate.connection.url", "jdbc:mysql://" + host + ":" + port + "/" + dbName);
    configuration.setProperty("hibernate.connection.username", user);
    configuration.setProperty("hibernate.connection.password", pass);
    configuration.setProperty("hibernate.c3p0.min_size", minConns);
    configuration.setProperty("hibernate.c3p0.max_size", maxConns);
    configuration.setProperty("hibernate.c3p0.max_statements", "50");
    configuration.setProperty("hibernate.connection.driver_class", "com.mysql.jdbc.Driver");
    configuration.setProperty("hibernate.connection.pool_size", "1");
    configuration.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5InnoDBDialect");
    configuration.setProperty("hibernate.current_session_context_class", "thread");
    configuration.setProperty("hibernate.cache.provider_class", "org.hibernate.cache.internal.NoCacheProvider");
    configuration.setProperty("hibernate.show_sql", "false");
    configuration.addResource("TransactionBean.hbm.xml");
    ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(
            configuration.getProperties()).build();
    sessionFactory = configuration.buildSessionFactory(serviceRegistry);

我在根本没有SQL数据库的机器上运行了这段代码，我得到的是：

16:27:24,719  WARN BasicResourcePool:1851 - com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask@62455eba 
-- Acquisition Attempt Failed!!! Clearing pending acquires. 
While trying to acquire a needed new resource, 
we failed to succeed more than the maximum number of
allowed acquisition attempts (30). 
Last acquisition attempt exception: 
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

这只是警告信息，没有例外。

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我需要验证连接是否已成功建立，并且我可以继续。否则，我需要更改参数并尝试连接到其他数据库。

我想我应该看看这里。

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我试图实现它，但验证不起作用。这是另一个问题。

您使用的是哪个Hibernate版本？org.Hibernate Hibernate core 4.3.5.FinalIt必须仅为警告，但是，您得到的异常为com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:Communications link failure，这是正确的，因为您没有数据库；