Getting null pointer exception at : SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();

Question

Whenever I run the program it gives: Exception in thread "main" java.lang.NullPointerException

I am just new to hibernate so please suggest me some techniques to get rid of these kinds of Exceptions.

I've used maven dependencies for loading the Jar files to my project.

This file contains the main function where I am trying to build a session and getting an exception.

Login.java file

public class Login {

    public static void main(String[] args) {

            SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
            Session session = sessionFactory.openSession();
            getStarted(session);
            session.close();
            sessionFactory.close();
    }
}

This is the hibernate.cfg.xml file which I had made.

hibernate.cfg.xml file

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

    <session-factory>

        <!-- Database Connection Settings -->
        <property name="connection.driver_class">org.postgresql.Driver</property>
        <property name="connection.url">jdbc:postgresql://localhost:5432/LMSHibernate</property>
        <property name="connection.username">postgres</property>
        <property name="connection.password">password</property>

        <!-- JDBC connection pool (use the build-in) -->
        <property name="connection.pool_size">1</property>

        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>

        <!-- Disable the second-level cache -->
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Drop and re-create a database schema on startup -->
        <property name="hbm2ddl.auto">update</property>

        <!-- Names the annotated entity class -->
        <mapping class="com.lms.entities.Employee" />

    </session-factory>
</hibernate-configuration>

Result:

Jan 18, 2019 6:12:38 PM org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {5.3.7.Final}
Jan 18, 2019 6:12:38 PM org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
Jan 18, 2019 6:12:40 PM org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {5.0.4.Final}
Jan 18, 2019 6:12:40 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
WARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)
Jan 18, 2019 6:12:40 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001005: using driver [org.postgresql.Driver] at URL [jdbc:postgresql://localhost:5432/LMSHibernate]
Jan 18, 2019 6:12:40 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001001: Connection properties: {user=postgres, password=****}
Jan 18, 2019 6:12:40 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreator
INFO: HHH10001003: Autocommit mode: false
Jan 18, 2019 6:12:40 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections <init>
INFO: HHH000115: Hibernate connection pool size: 1 (min=1)
Jan 18, 2019 6:12:40 PM org.hibernate.dialect.Dialect <init>
INFO: HHH000400: Using dialect: org.hibernate.dialect.PostgreSQLDialect
Jan 18, 2019 6:12:41 PM org.hibernate.engine.jdbc.env.internal.LobCreatorBuilderImpl useContextualLobCreation
INFO: HHH000424: Disabling contextual LOB creation as createClob() method threw error : java.lang.reflect.InvocationTargetException
Jan 18, 2019 6:12:41 PM org.hibernate.type.BasicTypeRegistry register
INFO: HHH000270: Type registration [java.util.UUID] overrides previous : org.hibernate.type.UUIDBinaryType@7b420819
Jan 18, 2019 6:12:41 PM org.hibernate.tuple.PojoInstantiator <init>
INFO: HHH000182: No default (no-argument) constructor for class: com.lms.entities.Employee (class must be instantiated by Interceptor)
Jan 18, 2019 6:12:42 PM org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnection
INFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@25cc7470] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.
Jan 18, 2019 6:12:42 PM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stop
INFO: HHH10001008: Cleaning up connection pool [jdbc:postgresql://localhost:5432/LMSHibernate]
Exception in thread "main" java.lang.NullPointerException
    at org.postgresql.jdbc2.AbstractJdbc2DatabaseMetaData.getColumns(AbstractJdbc2DatabaseMetaData.java:2502)
    at org.postgresql.jdbc4.AbstractJdbc4DatabaseMetaData.getColumns(AbstractJdbc4DatabaseMetaData.java:99)
    at org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl.populateTablesWithColumns(InformationExtractorJdbcDatabaseMetaDataImpl.java:350)
    at org.hibernate.tool.schema.extract.internal.InformationExtractorJdbcDatabaseMetaDataImpl.getTables(InformationExtractorJdbcDatabaseMetaDataImpl.java:337)
    at org.hibernate.tool.schema.extract.internal.DatabaseInformationImpl.getTablesInformation(DatabaseInformationImpl.java:120)
    at org.hibernate.tool.schema.internal.GroupedSchemaMigratorImpl.performTablesMigration(GroupedSchemaMigratorImpl.java:65)
    at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.performMigration(AbstractSchemaMigrator.java:207)
    at org.hibernate.tool.schema.internal.AbstractSchemaMigrator.doMigration(AbstractSchemaMigrator.java:114)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:183)
    at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72)
    at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310)
    at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:708)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:724)
    at com.lms.operations.Login.main(Login.java:20)