Java Tutorial/EJB3/DataSource JDBC

Inject DataSource

File: EmployeeBean.java

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import javax.annotation.Resource;
import javax.ejb.EJBException;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.sql.DataSource;
@Stateless
public class EmployeeBean implements EmployeeServiceLocal, EmployeeServiceRemote {
  @PersistenceContext(unitName="EmployeeService") private EntityManager manager;
  
  @Resource(mappedName="java:/DefaultDS") DataSource dataSource;
  public void doAction(){
    PreparedStatement ps = null;
    Connection con = null;
    try
    {
       con = dataSource.getConnection();
       System.out.println("Creating table PAYMENT...");
       ps = con.prepareStatement("drop TABLE PAYMENT");
       ps.execute();
       ps = con.prepareStatement("CREATE TABLE PAYMENT ( " +
                                 "CUSTOMER_ID INT, " +
                                 "AMOUNT DECIMAL (8,2), " +
                                 "TYPE CHAR (10), " +
                                 "CHECK_BAR_CODE CHAR (50), " +
                                 "CHECK_NUMBER INTEGER, " +
                                 "CREDIT_NUMBER CHAR (20), " +
                                 "CREDIT_EXP_DATE DATE" +
                                 ")");
       ps.execute();
       System.out.println("...done!");
    }
    catch (SQLException sql)
    {
       throw new EJBException(sql);
    }
    finally
    {
       try { if (ps != null) ps.close(); } catch (Exception e) {}
       try { if (con != null) con.close(); } catch (Exception e) {}
    }    
    Customer cust = new Customer();
    cust.setLastName("Bond");
    cust.setSsn(1L);
    manager.persist(cust);
    
    System.out.println("Saved");
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    cust.setLastName("new name");
    
    manager.persist(cust);
    
    cust = manager.find(Customer.class,1L);
    System.out.println(cust.getLastName());
    
    manager.remove(cust);
    
    
    
  }
}

Use JDBC In EJB

File: Customer.java

import javax.persistence.Entity;
import javax.persistence.EntityListeners;
import javax.persistence.Id;
import javax.persistence.PostRemove;
@Entity
@EntityListeners(EntityListener.class)
public class Customer implements java.io.Serializable {
  private String firstName;
  private String lastName;
  @Id
  private long ssn;
  public String getFirstName() {
    return firstName;
  }
  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public String getLastName() {
    return lastName;
  }
  public void setLastName(String lastName) {
    this.lastName = lastName;
  }

  public long getSsn() {
    return ssn;
  }
  public void setSsn(long ssn) {
    this.ssn = ssn;
  }
}