hqlexample.java

Hibernate基础教程一书源码.Hibernate是一个持久层开源框架

package com.hibernatebook.queries;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.hibernate.Hibernate;
import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HQLExample {

	public void executeSimpleHQL(Session session) {
		Query query = session.createQuery("from Product");
		List results = query.list();
		displayProductsList(results);
	}

	public void executeCommentedHQL(Session session) {
		String hql = "from Supplier";
		Query query = session.createQuery(hql);
		query.setComment("My HQL: " + hql);
		query.list();
	}

	public void executeFullyQualifiedHQL(Session session) {
		Query query = session
				.createQuery("from com.hibernatebook.queries.Product");
		List results = query.list();
		displayProductsList(results);
	}

	public void executeProjectionHQL(Session session) {
		Query query = session
				.createQuery("select product.name, product.price from Product product");
		List results = query.list();
		displayObjectsList(results);
	}

	public void executeHQLForRestrictions(Session session) {
		String hql = "from Product where price > 25.0 and name like 'Mou%'";
		Query query = session.createQuery(hql);
		List results = query.list();
		displayProductsList(results);
	}

	public void executeNamedParametersHQL(Session session) {
		String hql = "from Product where price > :price";
		Query query = session.createQuery(hql);
		query.setDouble("price", 25.0);
		List results = query.list();
		displayProductsList(results);
	}

	public void executeObjectNamedParametersHQL(Session session) {
		String supplierHQL = "from Supplier where name='MegaInc'";
		Query supplierQuery = session.createQuery(supplierHQL);
		Supplier supplier = (Supplier) supplierQuery.list().get(0);

		String hql = "from Product as product where product.supplier=:supplier";
		Query query = session.createQuery(hql);
		query.setEntity("supplier", supplier);
		List results = query.list();
		displayProductsList(results);
	}

	public void executePagingHQL(Session session) {
		Query query = session.createQuery("from Product");
		query.setFirstResult(1);
		query.setMaxResults(2);
		List results = query.list();
		displayProductsList(results);
	}

	public void executeUniqueResultHQL(Session session) {
		String hql = "from Product where price>25.0";
		Query query = session.createQuery(hql);
		query.setMaxResults(1);
		Product product = (Product) query.uniqueResult();
		// test for null here if needed

		List results = new ArrayList();
		results.add(product);
		displayProductsList(results);
	}

	public void executeOrderHQL(Session session) {
		String hql = "from Product p where p.price>25.0 order by p.price desc";
		Query query = session.createQuery(hql);
		List results = query.list();
		displayProductsList(results);
	}

	public void executeOrderTwoPropertiesHQL(Session session) {
		String hql = "from Product p order by p.supplier.name asc, p.price asc";
		Query query = session.createQuery(hql);
		List results = query.list();
		displayProductsList(results);
	}

	public void executeAssociationsHQL(Session session) {
		String hql = "select s.name, p.name, p.price from Product p inner join p.supplier as s";
		Query query = session.createQuery(hql);
		List results = query.list();
		displayObjectsList(results);
	}

	public void executeAssociationObjectsHQL(Session session) {
		String hql = "from Product p inner join p.supplier as s";
		Query query = session.createQuery(hql);
		List results = query.list();
		displayObjectsList(results);
	}

	public void executeFetchAssociationsHQL(Session session) {
		String hql = "from Supplier s inner join fetch s.products as p";
		Query query = session.createQuery(hql);
		List results = query.list();
		displaySupplierList(results);
	}

	public void executeCountHQL(Session session) {
		String hql = "select min(product.price), max(product.price) from Product product";
		Query query = session.createQuery(hql);
		List results = query.list();
		displayObjectsList(results);
	}

	public void executeNamedQuery(Session session) {

		Query query = session
				.getNamedQuery("com.hibernatebook.queries.Product.HQLpricing");
		List results = query.list();
		displayObjectList(results);

		query = session
				.getNamedQuery("com.hibernatebook.queries.Product.SQLpricing");
		results = query.list();
		displayObjectList(results);
	}

	public void executeScalarSQL(Session session) {
		String sql = "select avg(product.price) as avgPrice from Product product";

		SQLQuery query = session.createSQLQuery(sql);
		query.addScalar("avgPrice", Hibernate.DOUBLE);
		List results = query.list();
		displayObjectList(results);

	}

	public void executeSelectSQL(Session session) {
		String sql = "select {supplier.*} from Supplier supplier";

		SQLQuery query = session.createSQLQuery(sql);
		query.addEntity("supplier", Supplier.class);
		List results = query.list();
		displaySupplierList(results);

	}

	public void executeUpdateHQL(Session session) {
		String hql = "update Supplier set name = :newName where name = :name";
		Query query = session.createQuery(hql);
		query.setString("name", "SuperCorp");
		query.setString("newName", "MegaCorp");
		int rowCount = query.executeUpdate();
		System.out.println("Rows affected: " + rowCount);

		// See the results of the update
		query = session.createQuery("from Supplier");
		List results = query.list();

		displaySupplierList(results);
	}

	public void executeDeleteHQL(Session session) {
		String hql = "delete from Product where name = :name";
		Query query = session.createQuery(hql);
		query.setString("name", "Mouse");
		int rowCount = query.executeUpdate();
		System.out.println("Rows affected: " + rowCount);

		// See the results of the update
		query = session.createQuery("from Product");
		List results = query.list();

		displayProductsList(results);
	}

	public void populate(Session session) {

		Supplier superCorp = new Supplier();
		superCorp.setName("SuperCorp");
		session.save(superCorp);

		Supplier megaInc = new Supplier();
		megaInc.setName("MegaInc");
		session.save(megaInc);

		Product mouse = new Product("Mouse", "Optical Wheel Mouse", 20.0);
		mouse.setSupplier(superCorp);
		superCorp.getProducts().add(mouse);

		Product mouse2 = new Product("Mouse", "One Button Mouse", 22.0);
		mouse2.setSupplier(superCorp);
		superCorp.getProducts().add(mouse2);

		Product keyboard = new Product("Keyboard", "101 Keys", 30.0);
		keyboard.setSupplier(megaInc);
		megaInc.getProducts().add(keyboard);

		Software webBrowser = new Software("Web Browser", "Blocks Pop-ups",
				75.0, "2.0");
		webBrowser.setSupplier(superCorp);
		superCorp.getProducts().add(webBrowser);

		Software email = new Software("Email", "Blocks spam", 49.99,
				"4.1 RMX Edition");
		email.setSupplier(megaInc);
		megaInc.getProducts().add(email);
	}

	public void displayObjectList(List list) {
		Iterator iter = list.iterator();
		if (!iter.hasNext()) {
			System.out.println("No objects to display.");
			return;
		}
		while (iter.hasNext()) {
			Object obj = iter.next();
			System.out.println(obj.getClass().getName());
			System.out.println(obj);
		}
	}

	public void displayObjectsList(List list) {
		Iterator iter = list.iterator();
		if (!iter.hasNext()) {
			System.out.println("No objects to display.");
			return;
		}
		while (iter.hasNext()) {
			System.out.println("New object");
			Object[] obj = (Object[]) iter.next();
			for (int i = 0; i < obj.length; i++) {
				System.out.println(obj[i]);
			}

		}
	}

	public void displayProductsList(List list) {
		Iterator iter = list.iterator();
		if (!iter.hasNext()) {
			System.out.println("No products to display.");
			return;
		}
		while (iter.hasNext()) {
			Product product = (Product) iter.next();
			String msg = product.getSupplier().getName() + "\t";
			msg += product.getName() + "\t";
			msg += product.getPrice() + "\t";
			msg += product.getDescription();
			System.out.println(msg);
		}
	}

	public void displaySoftwareList(List list) {
		Iterator iter = list.iterator();
		if (!iter.hasNext()) {
			System.out.println("No software to display.");
			return;
		}
		while (iter.hasNext()) {
			Software software = (Software) iter.next();
			String msg = software.getSupplier().getName() + "\t";
			msg += software.getName() + "\t";
			msg += software.getPrice() + "\t";
			msg += software.getDescription() + "\t";
			msg += software.getVersion();
			System.out.println(msg);
		}
	}

	public void displaySupplierList(List list) {
		Iterator iter = list.iterator();
		if (!iter.hasNext()) {
			System.out.println("No suppliers to display.");
			return;
		}
		while (iter.hasNext()) {
			Supplier supplier = (Supplier) iter.next();
			String msg = supplier.getName();
			System.out.println(msg);
		}
	}

	public static void main(String args[]) throws Exception {
		if (args.length > 1) {
			System.out.println("One parameter expected but " + args.length
					+ " received.");
			return;
		}

		HQLExample example = new HQLExample();

		SessionFactory factory = new Configuration().configure()
				.buildSessionFactory();

		Session session = factory.openSession();
		session.beginTransaction();

		String action = args[0];
		if (action.equalsIgnoreCase(POPULATE)) {
			example.populate(session);
		} else {
			action = "execute" + action;

			Method method = HQLExample.class.getMethod(action,
					new Class[] { Session.class });
			method.invoke(example, new Object[] { session });
		}

		session.getTransaction().commit();
		session.close();
	}

	private static final String POPULATE = "populate";
}