Exception in thread "main" java.lang.ExceptionInInitializerError
    at ru.codesteps.hibernatetest.HibernateUtil.<clinit>(HibernateUtil.java:17)
    at ru.codesteps.hibernatetest.HibernateTest.main(HibernateTest.java:8)
Caused by: javax.persistence.PersistenceException: Unable to execute JPA schema generation create command [create table user (id int8 not null, age int4, name varchar(255), primary key (id))]
    at org.hibernate.jpa.internal.schemagen.GenerationTargetToDatabase.acceptCreateCommands(GenerationTargetToDatabase.java:64)
    at org.hibernate.jpa.internal.schemagen.JpaSchemaGenerator.doGeneration(JpaSchemaGenerator.java:507)
    at org.hibernate.jpa.internal.schemagen.JpaSchemaGenerator.access$300(JpaSchemaGenerator.java:69)
    at org.hibernate.jpa.internal.schemagen.JpaSchemaGenerator$Generation.execute(JpaSchemaGenerator.java:184)
    at org.hibernate.jpa.internal.schemagen.JpaSchemaGenerator.performGeneration(JpaSchemaGenerator.java:76)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:857)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:843)
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:399)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842)
    at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:73)
    at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:54)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
    at ru.codesteps.hibernatetest.HibernateUtil.<clinit>(HibernateUtil.java:15)
    ... 1 more
Caused by: org.postgresql.util.PSQLException: ERROR: syntax error at or near "user"
  Позиция: 14
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2103)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1836)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:257)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:512)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:374)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:366)
    at org.hibernate.jpa.internal.schemagen.GenerationTargetToDatabase.acceptCreateCommands(GenerationTargetToDatabase.java:61)
    ... 14 more

<dependencies>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>4.3.1.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.1-api</artifactId>
        <version>1.0.0.Final</version>
    </dependency>
    <dependency>
        <groupId>postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>9.1-901-1.jdbc4</version>
    </dependency>
</dependencies>

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
  <persistence-unit name="hibernate-test" transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://localhost:5432/postgres"/>
      <property name="javax.persistence.jdbc.user" value="postgres"/>
      <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
      <property name="javax.persistence.jdbc.password" value="postgres"/>
      <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
      <property name="hibernate.cache.provider_class" value="org.hibernate.cache.NoCacheProvider"/>
      <property name="javax.persistence.schema-generation.database.action" value="create"/>
    </properties>
  </persistence-unit>
</persistence>

public class HibernateUtil {

    private static final String PERSISTENT_UNIT_NAME = "hibernate-test";

    private static final EntityManagerFactory emf;

    static {
        try {
            emf = Persistence.createEntityManagerFactory(PERSISTENT_UNIT_NAME);
        } catch (Throwable ex) {
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static EntityManager getEm() {
    return emf.createEntityManager();
    }
}

@Entity
@Table(name = "users")
public class User {
    ...
}