Спящий режим теряет соединение

Я использую hibernate для подключения моей базы данных mysql и выполнения транзакций.

Я использую один SessionFactory во всем приложении, и у меня нет других подключений к базе данных, но я получаю исключение:

java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3008)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3466)
    ... 21 common frames omitted
Wrapped by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 526 milliseconds ago.  The last packet sent successfully to the server was 1 milliseconds ago.
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3556)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3456)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3897)
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2524)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2677)
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2545)
    at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:4842)
    at org.hibernate.engine.jdbc.connections.internal.PooledConnections.poll(PooledConnections.java:84)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.getConnection(DriverManagerConnectionProviderImpl.java:186)
    at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:35)
    at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:99)
    ... 11 common frames omitted
Wrapped by: org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:97)
    at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:102)
    at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:129)
    at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getConnectionForTransactionManagement(LogicalConnectionManagedImpl.java:247)
    at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:254)
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.begin(JdbcResourceLocalTransactionCoordinatorImpl.java:203)
    at org.hibernate.engine.transaction.internal.TransactionImpl.begin(TransactionImpl.java:56)
    at org.hibernate.internal.AbstractSharedSessionContract.beginTransaction(AbstractSharedSessionContract.java:387)
    at com.kitaplist.common.book.dao.HibernateBookDao.find(HibernateBookDao.java:56)
    at com.kitaplist.common.Collector.lambda$collectMetaBooksAndNewBooks$1(Collector.java:137)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

Вот как я создаю свой SessionFactory:

public static SessionFactory getSessionFactory() {

    if (sessionFactory == null) {
        sessionFactory = new Configuration()
                .configure()
                .addAnnotatedClass(Seller.class)
                .addAnnotatedClass(Book.class)
                .buildSessionFactory();
    }

    return sessionFactory;
}

и вот функция, которую я использую в своем BookDao:

@Override
public void save(Book book) {
    Session session = sessionFactory.openSession();
    Transaction tx = session.beginTransaction();
    try {
        session.save(book);
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            tx.commit();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            session.close();
        }

    }
}

мое приложение искатель сканирует объект книги из Интернета и сохраняет объект в базе данных с помощью вышеуказанной функции сохранения. Я не мог найти причину этого исключения.

в командной консоли, я вижу, что соединение восстанавливается после его потери, здесь:

SLF4J: A number (289) of logging calls during the initialization phase have been intercepted and are
SLF4J: now being replayed. These are subject to the filtering rules of the underlying logging system.
SLF4J: See also http://www.slf4j.org/codes.html#replay
Wed Mar 14 16:36:29 UTC 2018 WARN: Establishing SSL connection without server identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 14 16:36:29 UTC 2018 WARN: Establishing SSL connection without server identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 14 16:36:30 UTC 2018 WARN: Establishing SSL connection without server identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Wed Mar 14 16:36:29 UTC 2018 WARN: Establishing SSL connection without server identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.


Wed Mar 14 16:47:14 UTC 2018 WARN: Establishing SSL connection without server identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

Wed Mar 14 16:47:17 UTC 2018 WARN: Establishing SSL connection without server identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.

Буду признателен за любую помощь.

Ответы

jdbc:mysql://db_user:[email protected]/mydb?autoReconnect=true

The last packet successfully received from the server was 526 milliseconds ago.  The last packet sent successfully to the server was 1 milliseconds ago.

java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3008)


Wrapped by: org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection
    at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)

jdbc:mysql://localhost:3306/Peoples?autoReconnect=true&useSSL=false

sessionFactory.isClosed();

public static SessionFactory getSessionFactory() {

    if (sessionFactory == null || sessionFactory.isClosed()) {
        sessionFactory = new Configuration()
                .configure()
                .addAnnotatedClass(Seller.class)
                .addAnnotatedClass(Book.class)
                .buildSessionFactory();
    }

    return sessionFactory;
}

   at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3556)
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3456)
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3897)

    // Check return value, if we get a java.io.EOFException, the server has gone away. We'll pass it on up the exception chain and let someone higher up
   // decide what to do (barf, reconnect, etc).

[mysqld]
max_allowed_packet=256M