SPEL Operators Spring Integration with Hibernate

Spring Data JPA tutorial

The Spring Data JPA API provides the JpaTemplate class to integrate the Spring application with JPA.

JPA (Java Persistence API) is a Sun specification for persistently storing objects in enterprise applications. Currently, it is used as an alternative to complex entity beans.

Many vendors provide implementations of the JPA specification, such as:

Hibernate Toplink iBatis OpenJPA, etc.

Advantages of Spring JpaTemplate

You can persist, update, delete, or search objects without writing front and back code, such as creating Persistence instance, creating EntityManagerFactory instance, creating EntityTransaction instance, creating EntityManager instance, submitting EntityTransaction instance, and closing EntityManager.

Therefore, it Saved a lot of code.

In this example, we will use Hibernate mode to implement JPA.

Example of Spring and JPA integration

Let's take a look at the simple steps to integrate Spring application with JPA:

Create the Account.java file Create the Account.xml file Create the AccountDao.java file Create the persistence.xml file Create the applicationContext.xml file Create the AccountsClient.java file

In this example, we will integrate the sleep application with spring. Let's see the jpa example with spring. Directory structure.

1Account.java

This is a simple POJO class.

Example

package com.w3codebox;
public class Account {
	private int accountNumber;
	private String owner;
	private double balance;
　　　　　　　　//no-arg and parameterized constructor
　　　　　　　　//getters and setters
}

2Account.xml

This mapping file contains all the information of the persistent class.

Example

<entity-mappings version="1.0"　
		xmlns="http://java.sun.com/xml/ns/persistence/orm"　
		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance　
		xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm　
		http://java.sun.com/xml/ns/persistence/orm_1_0.xsd">
	<entity class="com.w3codebox.Account">
		<table name="account100"></table>
		<attributes>
			<id name="accountNumber">
				<column name="accountnumber">/>
			</id>
			<basic name="owner">
				<column name="owner">/>
			</basic>
			<basic name="balance">
				<column name="balance">/>
			</basic>
		</attributes>
	</entity>
</entity-mappings>

3AccountDao.java

Example

package com.w3codebox;
import java.util.List;
import org.springframework.orm.jpa.JpaTemplate;
import org.springframework.transaction.annotation.Transactional;
@Transactional
public class AccountsDao{
	JpaTemplate template;
	public void setTemplate(JpaTemplate template) {
		this.template = template;
	}
	public void createAccount(int accountNumber, String owner, double balance) {
		Account　account　=　new　Account(accountNumber,owner,balance);
		template.persist(account);
	}
	public　void　updateBalance(int　accountNumber,double　newBalance){
		Account　account　=　template.find(Account.class,　accountNumber);
		if(account　!=　null){
			account.setBalance(newBalance);
		}
		template.merge(account);
	}
	public　void　deleteAccount(int　accountNumber){
		Account　account　=　template.find(Account.class,　accountNumber);
		if(account　!=　null)
			template.remove(account);
	}
	public　List<Account>　getAllAccounts(){
		List<Account>　accounts　=template.find("select　acc　from　Account　acc");
		return　accounts;
	}
}

4、persistence.xml

Example

<?xml　version="1.0"　encoding="UTF-8"?>
<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_1_0.xsd"　version="1.0">
　　　　
	<persistence-unit　name="ForAccountsDB">
		<mapping-file>com/w3codebox/Account.xml</mapping-file>
		<class>com.w3codebox.Account</class>
	</persistence-unit>
</persistence>

5、applicationContext.xml

Example

<?xml　version="1.0"　encoding="UTF-8"?>
<beans　xmlns="http://www.springframework.org/schema/beans　
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance　
	xmlns:tx="http://www.springframework.org/schema/tx"　
	xsi:schemaLocation="http://www.springframework.org/schema/beans　
	http://www.springframework.org/schema/beans/spring-beans-3.0.xsd　
	http://www.springframework.org/schema/tx
	http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">
　	　<tx:annotation-driven transaction-manager="jpaTxnManagerBean" proxy-target-class="true"/>
	　<bean id="dataSourceBean" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
		<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"></property>
		<property name="url" value="jdbc:oracle:thin:@localhost:<1521:xe"></property>
		<property name="username" value="system"></property>
		<property name="password" value="oracle"></property>
	</bean>
	　	　
　	　　<bean id="hbAdapterBean" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
	　	<property name="showSql" value="true"></property>
	　	<property name="generateDdl" value="true"></property>
	　	<property name="databasePlatform" value="org.hibernate.dialect.OracleDialect"></property>
	　</bean>
	<bean id="emfBean" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
	　	<property name="dataSource" ref="dataSourceBean"></property>
	　	<property name="jpaVendorAdapter" ref="hbAdapterBean"></property>
	　</bean>
	　
	　<bean id="jpaTemplateBean" class="org.springframework.orm.jpa.JpaTemplate">
　	　	<property name="entityManagerFactory" ref="emfBean"></property>
　	　</bean>
　	　
　	　<bean id="accountsDaoBean" class="com.w3codebox.AccountsDao">
　	　	<property name="template" ref="jpaTemplateBean"></property>
　	　</bean>
　	　　<bean id="jpaTxnManagerBean" class="org.springframework.orm.jpa.JpaTransactionManager">
		<property name="entityManagerFactory" ref="emfBean"></property>
	</bean>
　	　	
</beans>

generateDdl The properties will automatically create tables.

showSql The properties will be displayed on the console as SQL queries.

6、Accountsclient.java

Example

package com.w3codebox;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
public class AccountsClient{
public static void main(String[] args){
　ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
　AccountsDao accountsDao = context.getBean("accountsDaoBean", AccountsDao.class);
　accountsDao.createAccount(15, "Jai Kumar",　41000);
　accountsDao.createAccount(20, "Rishi ",　35000);
　System.out.println("Accounts created");
　//accountsDao.updateBalance(20,　50000);
　//System.out.println("Account balance updated");
　/*List<Account> accounts = accountsDao.getAllAccounts();
　for (int i = 0; i < accounts.size(); i++) {
　　　Account acc = accounts.get(i);
　　　System.out.println(acc.getAccountNumber())　+　" : "　+　acc.getOwner()　+　" ("　+　acc.getBalance()　+　);
　}*/
　　//accountsDao.deleteAccount(111);
　　//System.out.println("Account deleted");
　}
}

Output

Example

Hibernate: insert into account100 (balance, owner, accountnumber) values (?, ?, ?)
Hibernate: insert into account100 (balance, owner, accountnumber) values (?, ?, ?)
Accounts created

SPEL Operators Spring Integration with Hibernate

Spring Tutorial

Spring Data JPA tutorial

Advantages of Spring JpaTemplate

Example of Spring and JPA integration