Hibernate 3 / JPA: Simple Select Query returning ClassCastException

[James Dekker]

Am using Hibernate 3 / JPA on Java 6. Am trying to fetch a simple row from the database (which is populated).

Created the following JPA Annotated Domain Object:

@Entity
@Table(name = "person", catalog = "mydatabase", uniqueConstraints = {
		@UniqueConstraint(columnNames = "person_name") })
public class Person {
	private Integer id;
	
	private String personName;
	
	@Id
	@GeneratedValue(strategy = IDENTITY)
	@Column(name = "id", unique = true, nullable = false)
	public Integer getId() {
		return id;
	}
	
	@Column(name = "person_name", unique = true, nullable = false, length = 30)
	public String getPersonName() {
		return personName;
	}
	
	public void setPersonName(String personName) {
		this.person = person;
	}
}

My hibernate.cfg.xml file:

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.bytecode.use_reflection_optimizer">false</property>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mydatabase</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password"></property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <property name="current_session_context_class">thread</property>
        <mapping class="com.myapp.domain.Person"></mapping>
    </session-factory>
</hibernate-configuration>

Code snippet from calling class:

session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
org.hibernate.Query query = session.createQuery("SELECT p FROM Person p");
List<Person> persons = query.getResultList();

When I run the calling class, this is the exception I get:

java.lang.ClassCastException: org.hibernate.impl.QueryImpl cannot be cast to javax.persistence.Query
	at com.myapp.PersonApp(PersonApp.java:15)

Line 15 where this ClassCastException occurs is here:

org.hibernate.Query query = session.createQuery("SELECT p FROM Person p");

Here are my dependencies:

<dependencies>
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>5.0.8</version>
	</dependency>

	<dependency>
		<groupId>org.codehaus.mojo</groupId>
		<artifactId>hibernate3-maven-plugin</artifactId>
		<version>3.0</version>
	</dependency>

	<dependency>
		<groupId>org.hibernate</groupId>
		<artifactId>hibernate-annotations</artifactId>
		<version>3.5.6-Final</version>
	</dependency>

	<dependency>
		<groupId>org.hibernate</groupId>
		<artifactId>hibernate-commons-annotations</artifactId>
		<version>3.2.0.Final</version>
	</dependency>

	<dependency>
		<groupId>javax.transaction</groupId>
		<artifactId>jta</artifactId>
		<version>1.1</version>
	</dependency>

	<dependency>
		<groupId>org.eclipse.persistence</groupId>
		<artifactId>javax.persistence</artifactId>
		<version>2.0.0</version>
		<scope>provided</scope>
	</dependency>
</dependencies>

What I am I possibly doing wrong? I just want to call a simple select query against a person table.

What is the most simplest way to do a select query for one row of my Person table in Hibernate / JPA?

I am using session factory instead of entity manager.

Thank you for taking the time to read this.

[lavnish lalchandani]

Hi
Can you try two things
1) use query.list() instead of query.getResultList()
2) also instead of session.createQuery("SELECT p FROM Person p"); you can try session.createQuery("FROM Person");