businessservice.java

hibernate的经典练习

package com.ghy.test4;

import java.util.HashSet;
import java.util.Iterator;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Expression;

//三种检索方式,HQL,QBC,本地SQL
public class BusinessService {
	public static SessionFactory sessionFactory;
	static {
		try {
			Configuration config = new Configuration();
			config.addClass(Courses.class);
			config.addClass(Students.class);
			sessionFactory = config.buildSessionFactory();
		} catch (Exception e) {
			// TODO: handle exception
			e.printStackTrace();
		}
	}

	public void findCourseByNameHQL() {
		Session session = sessionFactory.openSession();
		Transaction ts = null;
		try {
			ts = session.beginTransaction();
			Query query = session
					.createQuery("from Courses as c where c.name =  :name");
			query.setString("name", "数学");
			List list = query.list();
			ts.commit();
			Iterator iterator = list.iterator();
			while (iterator.hasNext()) {
				Courses courses = (Courses) iterator.next();
				System.out.println("HQL");
				System.out.print(courses.getId());
				System.out.print(":");
				System.out.println(courses.getName());

			}
		} catch (Exception e) {
			// TODO: handle exception
			if (ts != null) {
				// Something went wrong; discard all partial changes
				ts.rollback();
			}
			e.printStackTrace();
		} finally {
			session.close();
		}

	}

	public void findStudentByNameQBC() {
		Session session = sessionFactory.openSession();
		Transaction ts = null;
		try {
			ts = session.beginTransaction();
			Criteria cria = session.createCriteria(Students.class);
			Criterion crin = Expression.eq("studentNumber", "ghy");
			cria.add(crin);
			List list = cria.list();
			Iterator iterator = list.iterator();
			while (iterator.hasNext()) {
				Students students = (Students) iterator.next();
				System.out.println("CBQ");
				System.out.print(students.getId());
				System.out.print(":");
				System.out.println(students.getStudentNumber());

			}
			ts.commit();
		} catch (Exception e) {
			// TODO: handle exception
			if (ts != null) {
				// Something went wrong; discard all partial changes
				ts.rollback();
			}
			e.printStackTrace();
		} finally {
			session.close();
		}
	}

	public void findCourseByIdSQL() {
		Session session = sessionFactory.openSession();
		Transaction ts = null;
		try {
			ts = session.beginTransaction();
			String sql = "select {c.*} from courses c where  c.id  like    :id";
			SQLQuery sqlQuery = session.createSQLQuery(sql);
			sqlQuery.addEntity("c", Courses.class);
			sqlQuery.setString("id", "24_");
			

			List list = sqlQuery.list();
			Iterator iterator = list.iterator();
			while (iterator.hasNext()) {
				Courses courses = (Courses) iterator.next();
				System.out.println("SQL");
				System.out.print(courses.getId());
				System.out.print(":");
				System.out.println(courses.getName());

			}
			ts.commit();
		} catch (Exception e) {
			// TODO: handle exception
			if (ts != null) {
				// Something went wrong; discard all partial changes
				ts.rollback();
			}
			e.printStackTrace();
		} finally {
			session.close();
		}

	}

	public void test() {
		findCourseByNameHQL();
		findStudentByNameQBC();
		findCourseByIdSQL();
	}

	public static void main(String[] args) {
		BusinessService obj = new BusinessService();
		obj.test();
		sessionFactory.close();
	}

}