IT Education Guidance - Hibernate: Hibernate ( Mapping

Hibernate ( Mapping – One-To-One ) XML Application

Hibernate ( Mapping – One-To-One ) XML Application

One-to-one relationship occurs when one entity is mapping exactly one occurrence in another entity.

A one-to-one relationship table design, a “stock” table contains exactly one record in “stockdetails” table.

Both tables have the same stockid as primary key.

In “stockdetails” table, stockid is the primary key and also a foreign key to STOCK table.

CREATE TABLE IF NOT EXISTS `stock` (

`stockid` int(11) NOT NULL,

`stockcode` varchar(50) NOT NULL,

`stockname` varchar(100) NOT NULL,

PRIMARY KEY (`stockid`),

UNIQUE KEY `stockcode` (`stockcode`,`stockname`)

)

CREATE TABLE IF NOT EXISTS `stockdetails` (

`stockid` int(11) NOT NULL,

`companyname` varchar(100) NOT NULL,

`companydesc` varchar(100) NOT NULL,

`remark` varchar(50) NOT NULL,

`listeddate` date NOT NULL,

PRIMARY KEY (`stockid`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1;

ALTER TABLE `stockdetails`

ADD CONSTRAINT `stockdetails_ibfk_1` FOREIGN KEY (`stockid`) REFERENCES `stock` (`stockid`) ON DELETE CASCADE ON UPDATE CASCADE;

Step 1 - Create POJO (Model) classes ( Stock.java and StockDetails.java)

Step 2 - Create mapping files ( stock.hbm.xml and stockdetails.hbm.xml )

Step 3 - Hibernate Configurations ( hibernate.cfg.xml )

Step 4 - Create class to do the execution ( ExecuteApplication.java )

Step 1 - Create POJO classes

Create POJO (Plain Old Java Object) classes that represents the Stock, and StockDetails.

package pojo;

import java.io.Serializable;

public class Stock implements Serializable {

/**

private static final long serialVersionUID = 1L;

private Integer stockId;

private String stockCode;

private String stockName;

private StockDetails stockDetails;

//TODO Generate getters and setters

}

package pojo;

import java.io.Serializable;

import java.util.Date;

public class StockDetails implements Serializable {

/**

private static final long serialVersionUID = 1L;

private Integer stockId;

private String compName;

private String compDesc;

private String remark;

private Date listedDate;

private Stock stock;

//TODO Generate getters and setters

}

Step 2 - Create mapping file

Create a mapping file “Stock.hbm.xml” which maps “StockDetails.java” POJO and the “employee” table in the database.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

</id>

</property>

</property>

<one-to-one name="stockDetails" class="pojo.StockDetails"

cascade="save-update"></one-to-one>

</class>

</hibernate-mapping>

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC

"-//Hibernate/Hibernate Mapping DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping>

<param name="property">stock</param>

</generator>

</id>

</property>

</property>

</property>

</property>

<one-to-one name="stock" class="pojo.Stock" constrained="true"></one-to-one>

</class>

</hibernate-mapping>

Step 3 - Hibernate Configurations

Create configuration file name as hibernate.cfg.xml and save it.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-configuration PUBLIC

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<hibernate-configuration>

<session-factory>

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/myworkspace</property>

<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>

</session-factory>

</hibernate-configuration>

Step 4 - Create Execute class

Create a ExecuteApplication class to do the execution.

package impl;

import java.util.Date;

import java.util.Iterator;

import java.util.List;

import org.hibernate.Session;

import org.hibernate.Transaction;

import org.hibernate.cfg.AnnotationConfiguration;

import org.hibernate.cfg.Configuration;

import pojo.Stock;

import pojo.StockDetails;

public class ExecuteApplication {

/**

* @param args

public static void main(String[] args) {

ExecuteApplication executeEmployee = new ExecuteApplication();

executeEmployee.addStock();

executeEmployee.listStocks();

}

private void addStock(){

Transaction transaction = null;

Session hbSession = new Configuration().configure("config/hibernate.cfg.xml")

.buildSessionFactory().openSession();

try{

transaction = hbSession.beginTransaction();

Stock stock = new Stock();

stock.setStockId(123456);

stock.setStockCode("NB100");

stock.setStockName("Notebooks");

StockDetails stockDetails = new StockDetails();

stockDetails.setCompName("Abans");

stockDetails.setCompDesc("Pionior in Notebooks");

stockDetails.setRemark("Good Service");

stockDetails.setListedDate(new Date());

stock.setStockDetails(stockDetails);

stockDetails.setStock(stock);

hbSession.save(stock);

hbSession.getTransaction().commit();

System.out.println("Insert the Stock Record");

}catch (Exception e) {

if(null != transaction){

transaction.rollback();

}

e.printStackTrace();

}finally{

hbSession.flush();

hbSession.close();

}

private void listStocks(){

Transaction transaction = null;

Session hbSession = new Configuration().configure("config/hibernate.cfg.xml")

.buildSessionFactory().openSession();

try{

transaction = hbSession.beginTransaction();

@SuppressWarnings("unchecked")

List<Stock> stockList = hbSession.createQuery("FROM Stock").list();

for(Iterator<Stock> iterator = stockList.iterator(); iterator.hasNext();){

Stock stock = iterator.next();

System.out.println("");

System.out.println("StockId : " + stock.getStockId());

System.out.println("StockCode : " + stock.getStockCode());

System.out.println("StockName : " + stock.getStockName());

System.out.println("CompanyName : " + stock.getStockDetails().getCompName());

System.out.println("CompanyDesc : " + stock.getStockDetails().getCompDesc());

System.out.println("Remark : " + stock.getStockDetails().getRemark());

System.out.println("ListedDate : " + stock.getStockDetails().getListedDate());

}

hbSession.getTransaction().commit();

}catch (Exception e) {

if(null != transaction){

transaction.rollback();

}

e.printStackTrace();

}finally{

hbSession.flush();

hbSession.close();

}

Thursday, August 22, 2013

Hibernate ( Mapping – One-To-One ) XML Application

Hibernate ( Mapping – One-To-One ) XML Application