loginpersistence.java

一个简单的登陆程序

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package logintest;

import javax.persistence.EntityManager;
import javax.persistence.Persistence;

/**
 *
 * @author Administrator
 */
public class LogInPersistence {
        
    static  EntityManager em = Persistence.createEntityManagerFactory("LogInTestPU").createEntityManager();
    public static EntityManager getEm() {
        return em;
    }
    public static  void persist(Object object) {
        
        em.getTransaction().begin();
        try {
            em.persist(object);
            em.getTransaction().commit();
        } catch (Exception e) {
            e.printStackTrace();
            em.getTransaction().rollback();
        } 
    }

}