hibernate結合postgresql資料庫在專案中的使用
阿新 • • 發佈：2018-12-18
新增mvn依賴：
<!-- hibernate dependence --> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>5.1.0.Final</version> </dependency> <dependency> <groupId>org.hibernate.javax.persistence</groupId> <artifactId>hibernate-jpa-2.1-api</artifactId> <version>1.0.0.Final</version> </dependency> <dependency> <groupId>org.hibernate.common</groupId> <artifactId>hibernate-commons-annotations</artifactId> <version>5.0.1.Final</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>5.0.1.Final</version> </dependency> <!-- postgresql dependence --> <dependency> <groupId>org.postgresql</groupId> <artifactId>postgresql</artifactId> <!-- <version>9.4-1201-jdbc41</version> --> <version>9.4.1208.jre7</version> </dependency>
實現hibernate的實體類和對映關係
新增postgresql的config檔案hibernate.cfg.xml
<?xml version='1.0' encoding='utf-8'?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN" "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="connection.url."/> <property name="connection.driver_class"/> <property name="connection.username"/> <property name="connection.password"/> <!-- DB schema will be updated if needed --> <!-- <property name="hbm2ddl.auto">update</property> --> </session-factory> </hibernate-configuration>
先實現一個session工廠物件類SessionFactoryUtil.java
public class SessionFactoryUtil { private volatile static SessionFactoryUtil m_UtilInstance = null; private static SessionFactory m_SessionFactory= null; public final String CONFIG_FILE = "hibernate2.cfg.xml"; private SessionFactoryUtil(){ try{ String rcPath = this.getClass().getClassLoader().getResource("./").getPath(); //String rcPath = "/app/web/m2m-core/leshan-server-orm/src/main/resources"; //String path = String.format("%1$s/%2$s", System.getProperty("user.dir"), CONFIG_FILE); String path = String.format("%1$s/%2$s", rcPath, CONFIG_FILE); File file = new File(path); StandardServiceRegistry serviceRegistry = null; if(file.exists()){ serviceRegistry=new StandardServiceRegistryBuilder().configure(file).build(); }else serviceRegistry=new StandardServiceRegistryBuilder().configure().build(); m_SessionFactory=new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory(); }catch(Exception e){ e.printStackTrace(); } } public static SessionFactoryUtil getInstance(){ if(m_UtilInstance == null){ synchronized(SessionFactoryUtil.class){ if(m_SessionFactory == null){ m_UtilInstance = new SessionFactoryUtil(); } } } return m_UtilInstance; } public SessionFactory getSessionFactory(){ return m_SessionFactory; } public static void closeSessionFactory(){ if(m_SessionFactory != null){ m_SessionFactory.close(); m_SessionFactory = null; m_UtilInstance = null; } } }
再實現一個實體類user
public class User implements java.io.Serializable {
private long uid;
private String name;
private String passwd;
private Long ts;
private User() {
}
private User(long uid) {
this.uid = uid;
}
public User(String name, String passwd) {
this.name = name;
this.passwd = passwd;
}
@Id
@SequenceGenerator(name = "user_uid_seq", allocationSize = 1, initialValue = 1, sequenceName = "user_uid_seq")
@GeneratedValue(generator = "user_uid_seq", strategy = GenerationType.SEQUENCE)
@Column(name = "uid", unique = true, nullable = false)
public long getUid() {
return this.uid;
}
private void setUid(long uid) {
this.uid = uid;
}
@Column(name = "name", unique = true, length = 256)
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
@Column(name = "passwd", length = 256)
public String getPasswd() {
return this.passwd;
}
public void setPasswd(String passwd) {
this.passwd = passwd;
}
@Column(name = "ts")
public Long getTs() {
return this.ts;
}
public void setTs(Long ts) {
this.ts = ts;
}
}最後實現介面userbean.java
public class UserBean implements IUserBean{
@Override
public boolean insertUser(User user){
if(null == user) return false;
try{
SessionFactory sessionFactory = SessionFactoryUtil.getInstance().getSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
Date dt = new Date();
user.setTs(dt.getTime());
session.save(user);
tx.commit();
session.close();
}
catch (Exception e){
System.out.println(e.getMessage());
System.out.printf("===========================\n");
e.printStackTrace();
return false;
}
return true;
}
@Override
public boolean deleteUserByUserName(String name){
boolean nRet = false;
if(null == name || "" == name)return nRet;
SessionFactory sessionFactory = SessionFactoryUtil.getInstance().getSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
try{
String hql="delete User as d where d.name=?";
Query query=session.createQuery(hql);
query.setParameter(0, name);
int tmpValue = query.executeUpdate();
System.out.println("[UserBean]Result of query " + String.valueOf(tmpValue));
tx.commit();
nRet = true;
}catch(Exception ex){
System.out.println("[UserBean] test delete exception" + ex.toString());
nRet = false;
if(tx != null) tx.rollback();
session.close();
}
session.close();
return nRet;
}
@Override
public boolean deleteUserAll(){
boolean nRet = false;
SessionFactory sessionFactory = SessionFactoryUtil.getInstance().getSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
try{
String hql="delete from User";
Query query=session.createQuery(hql);
int tmpValue = query.executeUpdate();
System.out.println("[UserBean]Result of query " + String.valueOf(tmpValue));
tx.commit();
nRet = true;
}catch(Exception ex){
System.out.println("[UserBean] test delete exception" + ex.toString());
nRet = false;
if(tx != null) tx.rollback();
session.close();
}
session.close();
return nRet;
}
@Override
public boolean updateUser(User user){
boolean nRet = false;
if(user == null)return nRet;
SessionFactory sessionFactory = SessionFactoryUtil.getInstance().getSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
try{
String hql="select count(*) from User as d where d.uid=?";
Query query=session.createQuery(hql).setParameter(0, user.getUid());
long ret = (Long) query.uniqueResult();
if(ret > 0){
session.update(user);
tx.commit();
nRet = true;
}else nRet = false;
}catch(Exception ex){
System.out.println("[UserBean] test delete exception" + ex.toString());
nRet = false;
if(tx != null) tx.rollback();
session.close();
}
session.close();
return nRet;
}
@Override
public User[] getUserAll(){
List<User> list = new ArrayList<User>();
User[] userArray = null;
SessionFactory sessionFactory = SessionFactoryUtil.getInstance().getSessionFactory();
Session session = sessionFactory.openSession();
try{
list = (List<User>)session.createQuery("select d from User d").list();
userArray = (User[])list.toArray(new User[0]);
}catch(Exception ex){
userArray = (User[])list.toArray(new User[0]);
System.out.println("[UserBean][getUserAll] exception" + ex.toString());
session.close();
}
session.close();
return userArray;
}
@Override
public User getUserByUserName(String name){
List<User> list = new ArrayList<User>();
User user = null;
if(null == name || "" == name)return user;
SessionFactory sessionFactory = SessionFactoryUtil.getInstance().getSessionFactory();
Session session = sessionFactory.openSession();
try{
list = (List<User>)session.createQuery("select d from User d where d.name=?").setString(0, name).list();
if(list.size()>0) user = list.get(0);
}catch(Exception ex){
System.out.println("[UserBean][getUserAll] exception" + ex.toString());
session.close();
}
session.close();
return user;
}
}