batchfetchtest.java

介绍了hibernate的入门有一些基本常用的事例

//$Id: BatchFetchTest.java,v 1.1 2004/08/29 12:04:14 oneovthafew Exp $
package org.hibernate.test.batchfetch;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import junit.framework.Test;
import junit.framework.TestSuite;

import org.hibernate.Hibernate;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.test.TestCase;

/**
 * @author Gavin King
 */
public class BatchFetchTest extends TestCase {
	
	public BatchFetchTest(String str) {
		super(str);
	}
	
	public void testBatchFetch() {
		Session s = openSession();
		Transaction t = s.beginTransaction();
		ProductLine cars = new ProductLine();
		cars.setDescription("Cars");
		Model monaro = new Model(cars);
		monaro.setName("monaro");
		monaro.setDescription("Holden Monaro");
		Model hsv = new Model(cars);
		hsv.setName("hsv");
		hsv.setDescription("Holden Commodore HSV");
		s.save(cars);
		
		ProductLine oss = new ProductLine();
		oss.setDescription("OSS");
		Model jboss = new Model(oss);
		jboss.setName("JBoss");
		jboss.setDescription("JBoss Application Server");
		Model hibernate = new Model(oss);
		hibernate.setName("Hibernate");
		hibernate.setDescription("Hibernate");
		Model cache = new Model(oss);
		cache.setName("JBossCache");
		cache.setDescription("JBoss TreeCache");
		s.save(oss);
		
		t.commit();
		s.close();
		
		s.getSessionFactory().evict(Model.class);
		s.getSessionFactory().evict(ProductLine.class);
		
		s = openSession();
		t = s.beginTransaction();
		
		List list = s.createQuery("from ProductLine pl order by pl.description").list();
		cars = (ProductLine) list.get(0);
		oss = (ProductLine) list.get(1);
		assertFalse( Hibernate.isInitialized( cars.getModels() ) );
		assertFalse( Hibernate.isInitialized( oss.getModels() ) );
		assertEquals( cars.getModels().size(), 2 ); //fetch both collections
		assertTrue( Hibernate.isInitialized( cars.getModels() ) );
		assertTrue( Hibernate.isInitialized( oss.getModels() ) );
		
		s.clear();
		
		list = s.createQuery("from Model m").list();
		hibernate = (Model) s.get(Model.class, hibernate.getId());
		hibernate.getProductLine().getId();
		for ( Iterator i=list.iterator(); i.hasNext(); ) {
			assertFalse( Hibernate.isInitialized( ( (Model) i.next() ).getProductLine() ) );
		}
		assertEquals( hibernate.getProductLine().getDescription(), "OSS" ); //fetch both productlines
		
		s.clear();
		
		Iterator iter = s.createQuery("from Model").iterate();
		list = new ArrayList();
		while ( iter.hasNext() ) {
			list.add( iter.next() );
		}
		Model m = (Model) list.get(0);
		m.getDescription(); //fetch a batch of 4
		
		s.clear();
		
		list = s.createQuery("from ProductLine").list();
		ProductLine pl = (ProductLine) list.get(0);
		ProductLine pl2 = (ProductLine) list.get(1);
		s.evict(pl2);
		pl.getModels().size(); //fetch just one collection! (how can we write an assertion for that??)
		
		t.commit();
		s.close();

		s = openSession();
		t = s.beginTransaction();
		list = s.createQuery("from ProductLine pl order by pl.description").list();
		cars = (ProductLine) list.get(0);
		oss = (ProductLine) list.get(1);
		assertEquals( cars.getModels().size(), 2 );
		assertEquals( oss.getModels().size(), 3 );
		s.delete(cars);
		s.delete(oss);
		t.commit();
		s.close();
	}

	
	protected String[] getMappings() {
		return new String[] { "batchfetch/ProductLine.hbm.xml" };
	}

	public static Test suite() {
		return new TestSuite(BatchFetchTest.class);
	}

}