Osnove JPA

Implementacije:

• Apache OpenJPA
• Hibernate EntityManager
• Oracle TopLink Essentials

Uputstvo:

 http://openjpa.apache.org/builds/1.2.1/apache-openjpa-1.2.1/docs/manual/manual.html

Primer POJO klase sa anotacijama:

@Entity
@Table(name="test_table")
public class TestTable implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name="id")
    private int id;

    @Column(name="int_field")
    private int integerField;

    @Column(name="string_field")
    private String stringField;

    private static final long serialVersionUID = 1L;

    public TestTable() {
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getIntegerField() {
        return this.integerField;
    }

    public void setIntegerField(int integerField) {
        this.integerField = integerField;
    }

    public String getStringField() {
        return this.stringField;
    }

    public void setStringField(String stringField) {
        this.stringField = stringField;
    }

}

Primer persistence.xml fajla:

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
    <persistence-unit name="eTestPu">
        <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
   	
        <class>model.TestTable</class>
        <properties>
          <property name="openjpa.ConnectionURL" value="jdbc:mysql://server.rcub.bg.ac.rs/baza?useUnicode=true&characterEncoding=utf-8"/>
          <property name="openjpa.ConnectionDriverName" value="com.mysql.jdbc.Driver"/>
          <property name="openjpa.ConnectionUserName" value="ognjen"/>
          <property name="openjpa.ConnectionPassword" value="lozinka"/>
          
          <property name="openjpa.jdbc.DBDictionary" value="SupportsSubselect=true"/>
        </properties>
    
    </persistence-unit>
</persistence>

Primer orm.xml fajla:

<?xml version="1.0" encoding="UTF-8" ?>
<entity-mappings xmlns="http://java.sun.com/xml/ns/persistence/orm"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_1_0.xsd"
    version="1.0">        

    <named-query name="TestTable.findAll">
        <query>
            select o
              from TestTable o
           </query>
    </named-query>
</entity-mappings>