One To One Mapping With Fetch Type Lazy : One To One Mapping « JPA « Java Tutorial

Java Tutorial
1. Language
2. Data Type
3. Operators
4. Statement Control
5. Class Definition
6. Development
7. Reflection
8. Regular Expressions
9. Collections
10. Thread
11. File
12. Generics
13. I18N
14. Swing
15. Swing Event
16. 2D Graphics
17. SWT
18. SWT 2D Graphics
19. Network
20. Database
21. Hibernate
22. JPA
23. JSP
24. JSTL
25. Servlet
26. Web Services SOA
27. EJB3
28. Spring
29. PDF
30. Email
31. J2ME
32. J2EE Application
33. XML
34. Design Pattern
35. Log
36. Security
37. Apache Common
38. Ant
39. JUnit
Java
Java Source Code / Java Documentation
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Tutorial » JPA » One To One Mapping 
22. 9. 3. One To One Mapping With Fetch Type Lazy

File: Address.java

import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Address {
  @Id
  private int id;

  private String street;

  private String city;

  private String state;

  private String zip;

  public int getId() {
    return id;
  }

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

  public String getStreet() {
    return street;
  }

  public void setStreet(String address) {
    this.street = address;
  }

  public String getCity() {
    return city;
  }

  public void setCity(String city) {
    this.city = city;
  }

  public String getState() {
    return state;
  }

  public void setState(String state) {
    this.state = state;
  }

  public String getZip() {
    return zip;
  }

  public void setZip(String zip) {
    this.zip = zip;
  }

  public String toString() {
    return "Address id: " + getId() ", street: " + getStreet() ", city: " + getCity()
        ", state: " + getState() ", zip: " + getZip();
  }

}

File: Student.java

import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.OneToOne;

@Entity
public class Student {
  @Id
  private int id;

  private String name;

  @OneToOne(fetch = FetchType.LAZY)
  private Address address;

  public int getId() {
    return id;
  }

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

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public Address getAddress() {
    return address;
  }

  public void setAddress(Address address) {
    this.address = address;
  }

  public String toString() {
    return "\n\nID:" + id + "\nName:" + name + "\n\n";
  }
}

File: Main.java

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.Query;

public class Main {
  static EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAService");
  static EntityManager em = emf.createEntityManager();

  public static void main(String[] athrows Exception {
    em.getTransaction().begin();
    
    
    Student student = new Student();
    student.setName("Joe");
    Address address = new Address();
    em.persist(address);
    
    student.setAddress(address);
      
    em.persist(student);
    em.flush();
    em.getTransaction().commit();

    
    
    
    Query query = em.createQuery("SELECT e FROM Student e");
    List<Student> list = (List<Student>query.getResultList();
    System.out.println(list.get(0).getAddress());
    
    
    em.close();
    emf.close();
    
    Helper.checkData();
  }
}

File: Helper.java

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;

public class Helper {
  public static void checkData() throws Exception {
    Class.forName("org.hsqldb.jdbcDriver");
    Connection conn = DriverManager.getConnection("jdbc:hsqldb:data/tutorial""sa""");
    Statement st = conn.createStatement();

    ResultSet mrs = conn.getMetaData().getTables(null, null, null, new String[] { "TABLE" });
    while (mrs.next()) {
      String tableName = mrs.getString(3);
      System.out.println("\n\n\n\nTable Name: "+ tableName);

      ResultSet rs = st.executeQuery("select * from " + tableName);
      ResultSetMetaData metadata = rs.getMetaData();
      while (rs.next()) {
        System.out.println(" Row:");
        for (int i = 0; i < metadata.getColumnCount(); i++) {
          System.out.println("    Column Name: "+ metadata.getColumnLabel(i + 1)",  ");
          System.out.println("    Column Type: "+ metadata.getColumnTypeName(i + 1)":  ");
          Object value = rs.getObject(i + 1);
          System.out.println("    Column Value: "+value+"\n");
        }
      }
    }
  }
}

File: persistence.xml

<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence" version="1.0">
  <persistence-unit name="JPAService" transaction-type="RESOURCE_LOCAL">
    <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
      <property name="hibernate.hbm2ddl.auto" value="update"/>
      <property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
      <property name="hibernate.connection.username" value="sa"/>
      <property name="hibernate.connection.password" value=""/>
      <property name="hibernate.connection.url" value="jdbc:hsqldb:data/tutorial"/>
    </properties>
  </persistence-unit>
</persistence>
  Download:  JPA-OneToOneMappingWithFetchTypeLazy.zip( 5,290 k)
22. 9. One To One Mapping
22. 9. 1. Retrieve One To One Mapped Entity
22. 9. 2. One To One Unidirectional
22. 9. 3. One To One Mapping With Fetch Type Lazy
22. 9. 4. One To One Mapping With Cascading.All
22. 9. 5. One To One Mapping Primary Key As Join Column
22. 9. 6. One To One Mapping Mapped By Field
22. 9. 7. One To One Mapping Bidirectional
22. 9. 8. One To One Mapping Based On Table Based ID
22. 9. 9. Bidirectional One To One Mapping
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.