mysql-怎么回事，Hibernate这样也能成功，但这么多警告，怎么回事？

mysql

2015-7-14 20:58:10 org.hibernate.annotations.common.reflection.java.JavaReflectionManager
INFO: HCANN000001: Hibernate Commons Annotations {4.0.5.Final}
2015-7-14 20:58:10 org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.10.Final}
2015-7-14 20:58:10 org.hibernate.cfg.Environment
INFO: HHH000206: hibernate.properties not found
2015-7-14 20:58:10 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
2015-7-14 20:58:10 org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
2015-7-14 20:58:10 org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
2015-7-14 20:58:10 org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: org/yang/model/Student.hbm.xml
2015-7-14 20:58:10 org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
2015-7-14 20:58:10 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH000402: Using Hibernate built-in connection pool (not for production use!)
2015-7-14 20:58:10 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql://localhost:3306/hibernate]
2015-7-14 20:58:10 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000046: Connection properties: {user=root, password=****}
2015-7-14 20:58:10 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH000006: Autocommit mode: false
2015-7-14 20:58:10 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 20 (min=1)
2015-7-14 20:58:10 org.hibernate.dialect.Dialect
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect
2015-7-14 20:58:10 org.hibernate.engine.jdbc.internal.LobCreatorBuilder useContextualLobCreation
INFO: HHH000423: Disabling contextual LOB creation as JDBC driver reported JDBC version [3] less than 4
2015-7-14 20:58:10 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)
2015-7-14 20:58:10 org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory
INFO: HHH000397: Using ASTQueryTranslatorFactory
Hibernate: insert into student (name, age, id) values (?, ?, ?)
2015-7-14 20:58:11 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop
INFO: HHH000030: Cleaning up connection pool [jdbc:mysql://localhost:3306/hibernate]