Class In Hierarchy Has Its Own Table : Mapping Inheritance « Hibernate « Java Tutorial
File: Main.java
import java.util.Iterator;
import java.util.List;
import org.hibernate.Session;
public class Main {
public static void main(String[] args) throws Exception {
HibernateUtil hibernateUtil = new HibernateUtil();
hibernateUtil
.executeSQLCommand("create table CD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2))");
hibernateUtil
.executeSQLCommand("create table SECD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2), newfeatures varchar)");
hibernateUtil
.executeSQLCommand("create table ICD(id varchar,title varchar,artist varchar,purchaseDate date,cost decimal(6,2),languages varchar, region int)");
Session session = hibernateUtil.getSession();
CD cd = new CD();
cd.setArtist("artist");
cd.setTitle("title");
String id = (String)session.save(cd);
System.out.println(id);
SpecialEditionCD scd = new SpecialEditionCD();
scd.setNewfeatures("new");
session.save(scd);
InternationalCD icd = new InternationalCD();
icd.setLanguages("ENG");
session.save(icd);
session.flush();
List cds = session.createQuery("from CD").list();
Iterator iter = cds.iterator();
while (iter.hasNext()) {
CD cd1 = (CD) iter.next();
System.out.println(cd1.getArtist());
}
session.close();
hibernateUtil.checkData("select * from CD");
hibernateUtil.checkData("select * from SECD");
hibernateUtil.checkData("select * from ICD");
}
}
File: CD.java
import java.util.Date;
public class CD {
String id;
String title;
String artist;
Date purchaseDate;
double cost;
public CD() {
}
public Date getPurchaseDate() {
return purchaseDate;
}
public void setPurchaseDate(Date purchaseDate) {
this.purchaseDate = purchaseDate;
}
public CD(String title, String artist, Date purchaseDate, double cost) {
this.title = title;
this.artist = artist;
this.purchaseDate = purchaseDate;
this.cost = cost;
}
public void setId(String id) {
this.id = id;
}
public String getId() {
return id;
}
public void setTitle(String title) {
this.title = title;
}
public String getTitle() {
return title;
}
public void setArtist(String artist) {
this.artist = artist;
}
public String getArtist() {
return artist;
}
public void setCost(double cost) {
this.cost = cost;
}
public double getCost() {
return cost;
}
}
File: InternationalCD.java
import java.util.*;
public class InternationalCD extends CD {
private String languages;
public InternationalCD() {
}
public InternationalCD(String title, String artist, Date purchaseDate, double cost, String language) {
super(title, artist, purchaseDate, cost);
languages = language;
}
public void setLanguages(String s) {
languages = s;
}
public String getLanguages() {
return languages;
}
}
File: log4j.properties
log4j.rootCategory=WARN, console log4j.appender.console=org.apache.log4j.ConsoleAppender log4j.appender.console.layout=org.apache.log4j.PatternLayout log4j.appender.console.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n log4j.appender.stdout.Target=System.out
File: SpecialEditionCD.java
import java.util.*;
public class SpecialEditionCD extends CD {
private String newfeatures;
public SpecialEditionCD() {
}
public SpecialEditionCD(String title, String artist, Date purchaseDate, double cost, String features) {
super(title, artist, purchaseDate, cost);
newfeatures = features;
}
public void setNewfeatures(String s) {
newfeatures = s;
}
public String getNewfeatures() {
return newfeatures;
}
}
File: CD.hbm.xml
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE hibernate-mapping
PUBLIC "-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
<class name="CD" table="cd">
<id name="Id" type="string" unsaved-value="null">
<column name="ID" sql-type="text" not-null="true"/>
<generator class="uuid.hex"/>
</id>
<property name="title"/>
<property name="artist"/>
<property name="purchaseDate" type="date"/>
<property name="cost" type="double"/>
</class>
<class name="SpecialEditionCD" table="secd">
<id name="id" type="string" unsaved-value="0">
<generator class="uuid.hex"/>
</id>
<property name="title"/>
<property name="artist"/>
<property name="purchaseDate" type="date"/>
<property name="cost" type="double"/>
<property name="newfeatures" type="string"/>
</class>
<class name="InternationalCD" table="icd">
<id name="id" type="string" unsaved-value="0">
<generator class="uuid.hex"/>
</id>
<property name="title"/>
<property name="artist"/>
<property name="purchaseDate" type="date"/>
<property name="cost" type="double"/>
<property name="languages"/>
</class>
</hibernate-mapping>
File: hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.hsqldb.jdbcDriver</property>
<property name="connection.url">jdbc:hsqldb:data/tutorial</property>
<property name="connection.username">sa</property>
<property name="connection.password"></property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.HSQLDialect</property>
<!-- Enable Hibernate's current session context -->
<property name="current_session_context_class">org.hibernate.context.ManagedSessionContext</property>
<property name="hibernate.cache.use_second_level_cache">false</property>
<property name="hibernate.cache.use_query_cache">false</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Mapping files -->
<mapping resource="CD.hbm.xml"/>
</session-factory>
</hibernate-configuration>
File: HibernateUtil.java
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.Statement;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
Session session;
Statement st;
Configuration config;
public HibernateUtil() throws Exception{
config = new Configuration().configure();
SessionFactory sessionFactory = config.buildSessionFactory();
session = sessionFactory.openSession();
// Load the JDBC driver.
Class.forName("org.hsqldb.jdbcDriver");
System.out.println("Driver Loaded.");
// Establish the connection to the database.
String url = "jdbc:hsqldb:data/tutorial";
Connection conn = DriverManager.getConnection(url, "sa", "");
System.out.println("Got Connection.");
st = conn.createStatement();
}
public Configuration getConfiguration(){
return config;
}
public Session getSession(){
return session;
}
public void executeSQLCommand(String sql) throws Exception {
st.executeUpdate(sql);
}
public void checkData(String sql) throws Exception {
ResultSet rs = st.executeQuery(sql);
ResultSetMetaData metadata = rs.getMetaData();
for (int i = 0; i < metadata.getColumnCount(); i++) {
System.out.print("\t"+ metadata.getColumnLabel(i + 1));
}
System.out.println("\n----------------------------------");
while (rs.next()) {
for (int i = 0; i < metadata.getColumnCount(); i++) {
Object value = rs.getObject(i + 1);
if (value == null) {
System.out.print("\t ");
} else {
System.out.print("\t"+value.toString().trim());
}
}
System.out.println("");
}
}
}
Download: HibernateClassInHierarchyHasItsOwnTable.zip( 4,864 k)| 21.8.Mapping Inheritance | ||||
| 21.8.1. | Mapping Class Hierarchy | | ||
| 21.8.2. | Class In Hierarchy Maps To One Table | | ||
| 21.8.3. | Class In Hierarchy Has Its Own Table | | ||