Java Persistence API Named Query Demo

Java Persistence API Named Query Demo

src\META-INF\persistence.xml
=========================

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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_2_0.xsd">
    <persistence-unit name="jcrud">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>com.xyz.bo.Customer</class>
  
    <properties>
        <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/test_db"/>
        <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
        <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver"/>
        <property name="hibernate.connection.username" value="root"/>
        <property name="hibernate.connection.password" value="root1"/>
        <!--
        First time comment next line and un comment this line
        as the following configuration creates table and inserts data into table, To you have select 1 option
        -->
        <!--<property name="hibernate.hbm2ddl.auto" value="create"/>
        -->
        <!--
        Second time on time the following configuration updates or selects data from
         table. So comment aforesaid line configuration
        -->
        <property name="hibernate.hbm2ddl.auto" value="update"/>
        <property name="hibernate.show_sql" value="true"/>
        <property name="hibernate.format_sql" value="true"/>
   </properties>
   
    </persistence-unit>
</persistence>


src\CustomerMain.java
==================
import java.util.Iterator;
import java.util.List;
import java.util.Scanner;

import com.xyz.bo.Customer;
import com.xyz.service.CustomerService;

/**
 * @author Pedababu M
 *
 */
public class CustomerMain {

    public static void main(String args[]) {
        CustomerService customerService = new CustomerService();
        System.out.println("Choose an option");
        System.out.println("1. Add\n 2.Get All Customers");
        Scanner scanner = new Scanner(System.in);
        int choice = scanner.nextInt();

        switch (choice) {
        case 1:
           
            Customer customer = new Customer();
            //System.out.println("Enter the customer id");
            //customer.setCustomerId(scanner.nextInt());
            System.out.println("Enter the customer name");
            customer.setCustomerName(scanner.next());
            System.out.println("Enter the customer city");
            customer.setCity(scanner.next());
            customerService.addCustomer(customer);
            break;
        case 2:
            System.out.println("Enter the customer id");
            List customerList = null;
            customerList = customerService.getAllCustomers();
            Iterator iterator = customerList.iterator();
           
            while (iterator.hasNext()) {
                Object[] customer1 = (Object[])iterator.next();
            System.out.println("\nCustomer Name :"
                    + customer1[0] + "\n Customer ID :"
                    + customer1[1] + "\n Customer City :" + customer1[2]);
            }
        }
    }
}

src\com\xyz\bo\Customer.java
======================

package com.xyz.bo;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
import javax.persistence.Table;

/**
 * @author Pedababu M
 *
 */
@Entity
@Table(name="jpa_customer")
@NamedQuery(name="serchByCity", query="select customer.customerId,customer.customerName,customer.city  from Customer customer")
public class Customer {
    //JSR220 - JPA persistance
    @Id
    @Column(name="customer_id")
    @GeneratedValue(strategy=GenerationType.AUTO)
    private int customerId;
    @Column(name="customer_name")
    private String customerName;
    @Column(name="customer_city")
    private String city;
    /**
     * @return the customerId
     */
    public int getCustomerId() {
        return customerId;
    }
    /**
     * @param customerId the customerId to set
     */
    public void setCustomerId(int customerId) {
        this.customerId = customerId;
    }
    /**
     * @return the customerName
     */
    public String getCustomerName() {
        return customerName;
    }
    /**
     * @param customerName the customerName to set
     */
    public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }
    /**
     * @return the city
     */
    public String getCity() {
        return city;
    }
    /**
     * @param city the city to set
     */
    public void setCity(String city) {
        this.city = city;
    }
}

src\com\xyz\dao\CustomerDao.java
==========================
package com.xyz.dao;

import java.util.List;

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

import com.xyz.bo.Customer;

/**
 * @author Pedababu M
 *
 */
public class CustomerDao {
    public void addCustomer(Customer customer) {
        EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("jcrud");
        EntityManager entityManager = entityManagerFactory.createEntityManager();
        EntityTransaction entityTransaction = entityManager.getTransaction();
        try {
       
        entityTransaction.begin();
        entityManager.persist(customer);
        entityTransaction.commit();
        } catch(Exception exception){
            entityTransaction.rollback();
            exception.printStackTrace();
        }
        finally {
            entityManager.close();
        }
    }
    public List getAllCustomers() {
        EntityManagerFactory entityManagerFactory = Persistence.createEntityManagerFactory("jcrud");
        EntityManager entityManager = entityManagerFactory.createEntityManager();
        EntityTransaction entityTransaction = entityManager.getTransaction();
        Customer customer = null;
        List customerList = null;
        try {
       
        entityTransaction.begin();
        Query query =entityManager.createNamedQuery("serchByCity");
        //query.setParameter(1, "bangalore");
        //TypedQuery<Customer> query = entityManager.createQuery(" select customer from Customer customer", Customer.class);
        customerList = query.getResultList();
        entityTransaction.commit();
        } catch(Exception exception){
            entityTransaction.rollback();
            exception.printStackTrace();
        }
        finally {
            entityManager.close();
        }
        return customerList;
       
    }
}


src\com\xyz\service\CustomerService.java
===================================
package com.xyz.service;

import java.util.List;

import com.xyz.bo.Customer;
import com.xyz.dao.CustomerDao;

/**
 * @author Pedababu M
 *
 */
public class CustomerService {
    private CustomerDao customerDao = null;
    /**
     * @return the customerDao
     */
    public CustomerDao getCustomerDao() {
        if (customerDao == null) {
            customerDao = new CustomerDao();
        }
        return customerDao;
    }
   
    public void addCustomer(Customer customer){
        getCustomerDao().addCustomer(customer);
    }
    public List getAllCustomers(){
        List customerList =getCustomerDao().getAllCustomers();
        return customerList;
    }
}