Java framework --- CRUD operations of hibernate, --- hibernatecrud

Java framework --- CRUD operations of hibernate, --- hibernatecrud

CRUD refers to the abbreviation of the first letter of the words "Create", "Retrieve", "Update", and "Delete" during computing.

The following examples are provided to illustrate these operations:

Entity class:

package com.oumyye.model;public class Student {    private long id;    private String name;    private Class c;        public long getId() {        return id;    }    public void setId(long id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }            public Class getC() {        return c;    }    public void setC(Class c) {        this.c = c;    }    @Override    public String toString() {        return "Student [id=" + id + ", name=" + name + "]";    }        }

 

package com.oumyye.model;import java.util.HashSet;import java.util.Set;public class Class {    private long id;    private String name;    private Set<Student> students=new HashSet<Student>();        public long getId() {        return id;    }    public void setId(long id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public Set<Student> getStudents() {        return students;    }    public void setStudents(Set<Student> students) {        this.students = students;    }        }

Ing file:

Student.hbm.xml

<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"                                   "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
Class.hbm.xml
<?xml version="1.0"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"                                   "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
Tool: generated by myeclipse
package com.oumyye.util;import org.hibernate.HibernateException;import org.hibernate.Session;import org.hibernate.cfg.Configuration;import org.hibernate.cfg.AnnotationConfiguration;/** * Configures and provides access to Hibernate sessions, tied to the * current thread of execution.  Follows the Thread Local Session * pattern, see {@link http://hibernate.org/42.html }. */public class HibernateSessionFactory {    /**      * Location of hibernate.cfg.xml file.     * Location should be on the classpath as Hibernate uses       * #resourceAsStream style lookup for its configuration file.      * The default classpath location of the hibernate config file is      * in the default package. Use #setConfigFile() to update      * the location of the configuration file for the current session.        */    private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();    private static org.hibernate.SessionFactory sessionFactory;        private static Configuration configuration = new AnnotationConfiguration();    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";    private static String configFile = CONFIG_FILE_LOCATION;    static {        try {            configuration.configure(configFile);            sessionFactory = configuration.buildSessionFactory();        } catch (Exception e) {            System.err.println("%%%% Error Creating SessionFactory %%%%");            e.printStackTrace();        }    }    private HibernateSessionFactory() {    }        /**     * Returns the ThreadLocal Session instance.  Lazy initialize     * the <code>SessionFactory</code> if needed.     *     *  @return Session     *  @throws HibernateException     */    public static Session getSession() throws HibernateException {        Session session = (Session) threadLocal.get();        if (session == null || !session.isOpen()) {            if (sessionFactory == null) {                rebuildSessionFactory();            }            session = (sessionFactory != null) ? sessionFactory.openSession()                    : null;            threadLocal.set(session);        }        return session;    }    /**     *  Rebuild hibernate session factory     *     */    public static void rebuildSessionFactory() {        try {            configuration.configure(configFile);            sessionFactory = configuration.buildSessionFactory();        } catch (Exception e) {            System.err.println("%%%% Error Creating SessionFactory %%%%");            e.printStackTrace();        }    }    /**     *  Close the single hibernate session instance.     *     *  @throws HibernateException     */    public static void closeSession() throws HibernateException {        Session session = (Session) threadLocal.get();        threadLocal.set(null);        if (session != null) {            session.close();        }    }    /**     *  return session factory     *     */    public static org.hibernate.SessionFactory getSessionFactory() {        return sessionFactory;    }    /**     *  return session factory     *     *    session factory will be rebuilded in the next call     */    public static void setConfigFile(String configFile) {        HibernateSessionFactory.configFile = configFile;        sessionFactory = null;    }    /**     *  return hibernate configuration     *     */    public static Configuration getConfiguration() {        return configuration;    }}
Configuration File hibernate. cfg. xml
<? Xml version = '1. 0' encoding = 'utf-8'?> <! DOCTYPE hibernate-configuration PUBLIC "-// Hibernate/Hibernate Configuration DTD 3.0 // EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> 
Test class
Package com. oumyye. service; import java. util. iterator; import java. util. set; import org. hibernate. session; import org. hibernate. sessionFactory; import org. junit. after; import org. junit. before; import org. junit. test; import com. oumyye. model. class; import com. oumyye. model. student; import com. oumyye. util. hibernateSessionFactory; public class StudentTest {private SessionFactory sessionFactory = HibernateSessionFac Invalid. getSessionFactory (); private Session session; @ Before public void setUp () throws Exception {session = sessionFactory. openSession (); // generates a session. beginTransaction (); // enable transaction} @ After public void tearDown () throws Exception {session. getTransaction (). commit (); // submit the transaction session. close (); // close the session} @ Test public void testSaveClassAndStudent () {Class c = new Class (); c. setName ("08"); S Tudent s1 = new Student (); s1.setName ("Zhang San"); s1.setC (c); Student s2 = new Student (); s2.setName ("Li Si"); s2.setC (c ); session. save (s1); session. save (s2) ;}@ Test public void testLoadClass () {// Class c = (Class) session. load (Class. class, Long. valueOf (2); Class c = (Class) session. load (Class. class, Long. valueOf (1); System. out. println (c. getStudents ();} @ Test public void testGetClass () {// Class c = (Class) sess Ion. get (Class. class, Long. valueOf (2); Class c = (Class) session. get (Class. class, Long. valueOf (1); System. out. println (c. getStudents ();} @ Test public void testUpdateClass () {Session session1 = sessionFactory. openSession (); session1.beginTransaction (); Class c = (Class) session1.get (Class. class, Long. valueOf (1); session1.getTransaction (). commit (); // submit the transaction session1.close (); Session session2 = sessionFactor Y. openSession (); session2.beginTransaction (); c. setName ("08 2 2 2 2"); session2.update (c); session2.getTransaction (). commit (); // submit the transaction session2.close () ;}<! -- Update --> @ Test public void testSaveOrUpdateClass () {Session session1 = sessionFactory. openSession (); session1.beginTransaction (); Class c = (Class) session1.get (Class. class, Long. valueOf (1); session1.getTransaction (). commit (); // submit the transaction session1.close (); Session session2 = sessionFactory. openSession (); session2.beginTransaction (); c. setName ("08 3 3 3 3"); Class c2 = new Class (); c2.setName ("09 3 3 3 3"); session2. SaveOrUpdate (c); session2.saveOrUpdate (c2); session2.getTransaction (). commit (); // submit the transaction session2.close () ;}@ Test public void testMergeClass () {Session session1 = sessionFactory. openSession (); session1.beginTransaction (); Class c = (Class) session1.get (Class. class, Long. valueOf (1); session1.getTransaction (). commit (); // submit the transaction session1.close (); Session session2 = sessionFactory. openSession (); session2.be GinTransaction (); Class c2 = (Class) session2.get (Class. class, Long. valueOf (1); c. setName ("08 4 4 4 4"); session2.merge (c); session2.getTransaction (). commit (); // submit the transaction session2.close () ;}<! -- Delete --> @ Test public void testDeleteStudent () {Student student = (Student) session. load (Student. class, Long. valueOf (1); session. delete (student );}}
Common Methods for getting started with sessions

   

 
    
Query query = session. createQuery (hql): queries using hql Query statements;
 
    
Criteria cricriteria = session. createCriteria (Class clazz );
 
    
(3) Transaction tx = session. beginTransaction (); // start Transaction; tx. commit () commit Transaction;
 
    
Session. close (); // close the Session, and the persistent object managed by the session becomes out of management;
 
    
Session. save (Object obj); // Add
 
    
Session. update (Object obj); // update
 
    
Session. delete (Object obj); // delete
 
    
Object obj = session. get (Class clazz, Serialiazble id); // query records based on the primary key and return results;
 
    
Object obj = session. load (Class clazz, Serializable id); // The effect is the same as that of the get method, but it is lazy. That is, the Object is not returned before the get method is used;