How to connect with external mySQL database using hibernate

Question

Instead of using a local mySQL Database i created an external database with https://remotemysql.com/. The problem I am having is that I cant connect to the database.

This is my hibernate config file:

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">

<hibernate-configuration>
<session-factory>
    <!-- SQL Dialect -->
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

    <!-- Database Connection Settings -->
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://www.remotemysql.com:3306/oJv6mOSx3X</property>
    <property name="hibernate.connection.username">34kjldxck</property>
    <property name="hibernate.connection.password">mysecpw</property>
    <property name="show_sql">true</property>

    <!-- Specifying Session Context -->
    <property name="hibernate.current_session_context_class">org.hibernate.context.internal.ThreadLocalSessionContext</property>

    <!-- Mapping With Model Class Containing Annotations -->
    <mapping class="com.jcg.hibernate.maven.User" />
</session-factory>

This is how I am trying to connect to the database:

public class AppMain {
static Session sessionObj;
static SessionFactory sessionFactoryObj;

private static SessionFactory buildSessionFactory() {
    // Creating Configuration Instance & Passing Hibernate Configuration File
    Configuration configObj = new Configuration();
    configObj.configure("hibernate.cfg.xml");

    // Since Hibernate Version 4.x, ServiceRegistry Is Being Used
    ServiceRegistry serviceRegistryObj = new StandardServiceRegistryBuilder().applySettings(configObj.getProperties()).build(); 

    // Creating Hibernate SessionFactory Instance
    sessionFactoryObj = configObj.buildSessionFactory(serviceRegistryObj);
    return sessionFactoryObj;
}

public static void main(String[] args) {
    try {
        sessionObj = buildSessionFactory().openSession(); 
    } catch(Exception ex){
                ex.printStackTrace();
    }
 }
}

This is the error I get:

org.hibernate.exception.JDBCConnectionException: Error calling Driver#connect
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator$1$1.convert(BasicConnectionCreator.java:122)
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:140)
at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:58)
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:75)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:106)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.buildJdbcConnectionAccess(JdbcServicesImpl.java:260)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:94)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1885)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843)
at com.jcg.hibernate.maven.AppMain.buildSessionFactory(AppMain.java:24)
at com.jcg.hibernate.maven.AppMain.main(AppMain.java:30)
Caused by: java.sql.SQLException: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:1041)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3481)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2445)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2215)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:813)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
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:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:334)
at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:55)
... 14 more
Caused by: java.lang.ClassCastException: java.math.BigInteger cannot be cast to java.lang.Long
at com.mysql.jdbc.ConnectionImpl.buildCollationMapping(ConnectionImpl.java:992)
... 27 more
enter code here

Now I am guessing that the error is because of the connection url I guess. Whats strange that i get am Math exception(igInteger cannot be cast to java.lang.Long)

Answer 1

This type of error indicates error to connect to the database (search the exception for results). It is hard to say what is the reason. It could be related to the version of the connector.jar. I would check that but first. Also would check if you are able to connect to a local database from your hibernate framework.

Answer 2

if you scroll down into the error, in the caused by section , I think you have a field in database of type BigInteger and it's mapped to Long class field, which cause a ClassCastException

Hope it helps