<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
    <class>Entidade.Cliente</class>
    <properties>
        <property name="openjpa.localhost" dbnamejdbc:mysql://localhost:3306/acessos" />
        <property name="openjpa.ConnectionDriverName" value="com.mysql.jdbc.Driver" />
        <property name="openjpa.ConnectionUserName" value="root" />
        <property name="openjpa.ConnectionPassword" value="" />
        <property name="openjpa.DynamicEnhancementAgent" value="true" />
        <property name="openjpa.RuntimeUnenhancedClasses" value="supported" />
        <property name="openjpa.Log" value="SQL=TRACE" />
        <property name="openjpa.ConnectionFactoryProperties"
            value="PrettyPrint=true, PrettyPrintLineLength=72, PrintParameters=true, MaxActive=10, MaxIdle=5, MinIdle=2, MaxWait=60000" />
    </properties>
</persistence-unit>

EntityManager entityManager =
                Persistence.createEntityManagerFactory("Struct2").createEntityManager();

        Cliente Cliente = new Cliente();
        Cliente.setCpf("007");
        Cliente.setNome("teste");
        Cliente.setRg("2888");
        Cliente.setId(1);

        entityManager.persist(Cliente);
        entityManager.getTransaction().commit();

        entityManager.close();

@Id
     private int id;
     @Column
     private String nome;
     @Column
     private String cpf;
     @Column
     private String rg;

     public int getId() {
               return id;
     }
     public void setId(int id) {
               this.id = id;
     }
     public String getNome() {
               return nome;
     }
     public void setNome(String nome) {
               this.nome = nome;
     }
     public String getCpf() {
               return cpf;
     }
     public void setCpf(String cpf) {
               this.cpf = cpf;
     }
     public String getRg() {
               return rg;
     }
     public void setRg(String rg) {
               this.rg = rg;
     }