accountserviceimpl.java

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package service.impl;

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

import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;

import service.AccountService;
import domain.Account;

public class AccountServiceImpl implements AccountService {

	public Account findById(Integer id) {
		// TODO Auto-generated method stub
		return null;
	}

	public Account logon(Account account) {
		Session session = HibernateSessionFactory.getSession();
		Query query = session.getNamedQuery("findAccountByUsernameAndPassword");
		query.setParameter(0, account.getUsername());
		query.setParameter(1, account.getPassword());
		List list = query.list();
		session.close();
		if (list.size() > 0) {
			return (Account) list.get(0); //返回list的第一个数，list就只有一条记录，记录是Account的值
		} else {
			return null;
		}
	}

	public void register(Account account) {
		Session session = HibernateSessionFactory.getSession();
		Transaction tx = null;
		try {
			tx = session.beginTransaction();
			session.save(account);
			tx.commit();
		} catch (HibernateException e) {
			e.printStackTrace();
			tx.rollback();
		} finally {
			session.close();
		}

	}

	public boolean validate(String username) {
		Session session = HibernateSessionFactory.getSession();
		Query query = session.getNamedQuery("findAccountByUsername");
		query.setParameter(0, username); //设置from Account a where a.username = ? 问好的置
		Iterator it = query.iterate();
		boolean b = !it.hasNext(); //如果还有元素可以迭代，则返回 true，但这里只有一条记录，所以返回false,加上!,就返回true
		session.close();
		return b;
	}

}