- 創建Hibernate的配置文件
- 創建持久化類
- 創建對象-關係映射文件
- 通過Hibernate API編寫訪問數據庫的代碼
三、Hibernate的配置文件(hibernate.properties)
- hibernate.dialect=org.hibernate.dialect.MySQLDialect
- hibernate.connection.driver_class=com.mysql.jdbc.Driver hibernate.connection.url=jdbc:mysql://localhost:3306/SAMPLEDB
- hibernate.connection.username=root hibernate.connection.password=1234
- hibernate.show_sql=true
- 持久化類符合JavaBean的規範,包含一些屬性,以及與之對應的getXXX()和setXXX()方法。
- 持久化類有一個id屬性,用來惟一標識Customer類的每個對象。在面向對象術語中,這個id屬性被稱爲對象標識符(OID,Object Identifier),通常它都用整數表示
- Hibernate要求持久化類必須提供一個不帶參數的默認構造方法
- package mypack;
- import java.io.Serializable; import java.sql.Date;
- import java.sql.Timestamp;
- public
class Customer implements Serializable {
private Long id;
private String name;
private String email;
private String password;
private
int phone;
private String address;
private
char sex;
private
boolean married;
private String description;
private
byte[] p_w_picpath;
private Date birthday;
private Timestamp registeredTime;
public Customer(){}
public Long getId(){
return id;- }
private
void setId(Long id){
this.id = id;- }
public String getName(){
return name;- }
public
void setName(String name){
this.name=name;- }
public String getEmail(){
return email;- }
public
void setEmail(String email){
this.email =email ;- }
public String getPassword(){
return password;- }
public
void setPassword(String password){
this.password =password ;- }
public
int getPhone(){
return phone;- }
public
void setPhone(int phone){
this.phone =phone ;- }
public String getAddress(){
return address;- }
public
void setAddress(String address){
this.address =address ;- }
public
char getSex(){
return sex; }
public
void setSex(char sex){
this.sex =sex ; }
public
boolean isMarried(){
return married; }
public
void setMarried(boolean married){
this.married =married ; }
public String getDescription(){
return description; }
public
void setDescription(String description){
this.description =description ; }
public
byte[] getImage() {
return
this.p_w_picpath; }
public
void setImage(byte[] p_w_picpath) {
this.p_w_picpath = p_w_picpath; }
public Date getBirthday() {
return
this.birthday; }
public
void setBirthday(Date birthday) {
this.birthday = birthday; }
public Timestamp getRegisteredTime() {
return
this.registeredTime; }
public
void setRegisteredTime(Timestamp registeredTime) {
this.registeredTime = registeredTime; }
- }
- getXXX()和setXXX()方法可以採用任意的訪問級別,他的命名規則必須符合特定的命名規則,“get”和“set”後面緊跟屬性的名字,並且屬性名的首字母爲大寫,如name屬性的get方法爲getName()。
- 如果持久化類的屬性爲boolean類型,那麼它的get方法名可以用get做前綴也可以用is做前綴。
- drop database if exists SAMPLEDB;
- create database SAMPLEDB; use SAMPLEDB;
create table CUSTOMERS (- ID bigint not null primary key, NAME varchar(15) not null,
- EMAIL varchar(128) not null, PASSWORD varchar(8) not null,
- PHONE int , ADDRESS varchar(255),
- SEX char(1) , IS_MARRIED bit,
- DESCRIPTION text, IMAGE blob,
- BIRTHDAY date,
- REGISTERED_TIME timestamp
- <?xml version="1.0"?>
- <!DOCTYPE hibernate-mapping PUBLIC"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
- <hibernate-mapping> <class name="mypack.Customer" table="CUSTOMERS">
- <id name="id" column="ID" type="long"> <generator class="increment"/>
- </id> <property name="name" column="NAME" type="string" not-null="true" />
- <property name="email" column="EMAIL" type="string" not-null="true" /> <property name="password" column="PASSWORD" type="string" not-null="true"/>
- <property name="phone" column="PHONE" type="int" /> <property name="address" column="ADDRESS" type="string" />
- <property name="sex" column="SEX" type="character"/> <property name="married" column="IS_MARRIED" type="boolean"/>
- <property name="description" column="DESCRIPTION" type="text"/> <property name="p_w_picpath" column="IMAGE" type="binary"/>
- <property name="birthday" column="BIRTHDAY" type="date"/> <property name="registeredTime" column="REGISTERED_TIME" type="timestamp"/>
- </class>
- </hibernate-mapping>
<generator>子元素用來設定標識符生成器。Hibernate提供了提供了多種內置的實現。
<property>元素映射值類型屬性
- name屬性:指定持久化類的屬性的名字。
- column屬性:指定與類的屬性映射的表的字段名。
- type屬性:指定Hibernate映射類型。Hibernate映射類型是Java類型與SQL類型的橋樑。
- Hibernate既不會***到上層域模型中,也不會***到下層數據模型中。
- 軟件開發人員可以獨立設計域模型,不必強迫遵守任何規範。
- 數據庫設計人員可以獨立設計數據模型,不必強迫遵守任何規範。
- 對象-關係映射不依賴於任何程序代碼,如果需要修改對象-關係映射,只需修改XML文件,不需要修改任何程序,提高了軟件的靈活性,並且使維護更加方便。
- package mypack;
import javax.servlet.*;- import org.hibernate.*; import org.hibernate.cfg.Configuration;
- import java.io.*; import java.sql.Date;
- import java.sql.Timestamp; import java.util.*;
public
class BusinessService{
public
static SessionFactory sessionFactory;
/** 初始化Hibernate,創建SessionFactory實例 */
static{
try{
// 根據默認位置的Hibernate配置文件的配置信息,創建一個Configuration實例
- Configuration config = new Configuration();
//加載Customer類的對象-關係映射文件
- config.addClass(Customer.class);
// 創建SessionFactory實例 */
- sessionFactory = config.buildSessionFactory(); }catch(RuntimeException e){e.printStackTrace();throw e;}
- }
/** 查詢所有的Customer對象,然後調用printCustomer()方法打印Customer對象信息 */
public
void findAllCustomers(ServletContext context,PrintWriter out) throws Exception{- Session session = sessionFactory.openSession(); //創建一個會話
Transaction tx = null;
try { tx = session.beginTransaction(); //開始一個事務
- Query query=session.createQuery("from Customer as c order by c.name asc"); List customers=query.list();
for (Iterator it = customers.iterator(); it.hasNext();) { printCustomer(context,out,(Customer) it.next());- }
- tx.commit(); //提交事務
- }catch (RuntimeException e) {
if (tx != null) { - tx.rollback(); }
throw e; } finally {- session.close(); }
- }
/** 持久化一個Customer對象 */
public
void saveCustomer(Customer customer){- Session session = sessionFactory.openSession(); Transaction tx = null;
try { tx = session.beginTransaction();- session.save(customer); tx.commit();
}catch (RuntimeException e) {
if (tx != null) { tx.rollback();- }
throw e; - } finally { session.close();
- } }
/** 按照OID加載一個Customer對象,然後修改它的屬性 */
public
void loadAndUpdateCustomer(Long customer_id,String address){ Session session = sessionFactory.openSession();- Transaction tx = null;
try { - tx = session.beginTransaction();
- Customer c=(Customer)session.get(Customer.class,customer_id); c.setAddress(address);
- tx.commit();
- }catch (RuntimeException e) {
if (tx != null) { - tx.rollback(); }
throw e; } finally {- session.close(); }
- }
/**刪除Customer對象 */
public
void deleteCustomer(Customer customer){- Session session = sessionFactory.openSession(); Transaction tx = null;
try { tx = session.beginTransaction();- session.delete(customer); tx.commit();
}catch (RuntimeException e) {
if (tx != null) { tx.rollback();- }
throw e; - } finally { session.close();
- } }
/** 選擇向控制檯還是Web網頁輸出Customer對象的信息 */
private
void printCustomer(ServletContext context,PrintWriter out,Customer customer)throws Exception{
if(context!=null)- printCustomerInWeb(context,out,customer);
else
- printCustomer( out,customer); }
/** 把Customer對象的信息輸出到控制檯,如DOS 控制檯*/
private
void printCustomer(PrintWriter out,Customer customer)throws Exception{
byte[] buffer=customer.getImage();- FileOutputStream fout=new FileOutputStream("photo_copy.gif"); fout.write(buffer);
- fout.close();
- out.println("------以下是"+customer.getName()+"的個人信息------"); out.println("ID: "+customer.getId());
- out.println("口令: "+customer.getPassword()); out.println("E-Mail: "+customer.getEmail());
- out.println("電話: "+customer.getPhone()); out.println("地址: "+customer.getAddress());
- String sex=customer.getSex()=='M'? "男":"女"; out.println("性別: "+sex);
- String marriedStatus=customer.isMarried()? "已婚":"未婚"; out.println("婚姻狀況: "+marriedStatus);
- out.println("生日: "+customer.getBirthday()); out.println("註冊時間: "+customer.getRegisteredTime());
- out.println("自我介紹: "+customer.getDescription());
- }
/** 把Customer對象的信息輸出到動態網頁 */
private
void printCustomerInWeb(ServletContext context,PrintWriter out,Customer customer)throws Exception{
//保存照片
byte[] buffer=customer.getImage();- String path=context.getRealPath("/"); FileOutputStream fout=new FileOutputStream(path+"photo_copy.gif");
- fout.write(buffer); fout.close();
out.println("------以下是"+customer.getName()+"的個人信息------"+"<br>");- out.println("ID: "+customer.getId()+"<br>"); out.println("口令: "+customer.getPassword()+"<br>");
- out.println("E-Mail: "+customer.getEmail()+"<br>"); out.println("電話: "+customer.getPhone()+"<br>");
- out.println("地址: "+customer.getAddress()+"<br>"); String sex=customer.getSex()=='M'? "男":"女";
- out.println("性別: "+sex+"<br>"); String marriedStatus=customer.isMarried()? "已婚":"未婚";
- out.println("婚姻狀況: "+marriedStatus+"<br>"); out.println("生日: "+customer.getBirthday()+"<br>");
- out.println("註冊時間: "+customer.getRegisteredTime()+"<br>"); out.println("自我介紹: "+customer.getDescription()+"<br>");
- out.println("<img src='photo_copy.gif' border=0><p>"); }
public
void test(ServletContext context,PrintWriter out) throws Exception{
- Customer customer=new Customer(); customer.setName("Tom");
- customer.setEmail("[email protected]"); customer.setPassword("1234");
- customer.setPhone(55556666); customer.setAddress("Shanghai");
- customer.setSex('M'); customer.setDescription("I am very honest.");
//設置Customer對象的p_w_picpath屬性,它是字節數組,存放photo.gif文件中的二進制數據
//photo.gif文件和BusinessService.class文件位於同一個目錄下
InputStream in=this.getClass().getResourceAsStream("photo.gif");
byte[] buffer = new
byte[in.available()]; in.read(buffer);- customer.setImage(buffer);
//設置Customer對象的birthday屬性,它是java.sql.Date類型
- customer.setBirthday(Date.valueOf("1980-05-06"));
- saveCustomer(customer);
- findAllCustomers(context,out); loadAndUpdateCustomer(customer.getId(),"Beijing");
- findAllCustomers(context,out); deleteCustomer(customer);
- }
public
static
void main(String args[]) throws Exception {
new BusinessService().test(null,new PrintWriter(System.out,true));- sessionFactory.close(); }
- }
該方法調用Session的save()方法,把Customer對象持久化到數據庫中。
- tx = session.beginTransaction();
session.save(customer);
- tx.commit();
- insert into CUSTOMERS (ID, NAME, EMAIL, PASSWORD, PHONE, ADDRESS, SEX,
IS_MARRIED,DESCRIPTION, IMAGE, BIRTHDAY, REGISTERED_TIME)
- values(1,'Tom','[email protected]','1234',55556666,'Shanghai','M',0,'I am very honest.', ☺,'1980-05-06',null)
- <id name="id" column="ID" type="long">
<generator class="increment"/>
- </id>
該方法通過Query接口查詢所有的Customer對象。
- tx = session.beginTransaction(); //開始一個事務
Query query=session.createQuery("from Customer as c order by c.name asc");
List customers=query.list();
for (Iterator it = customers.iterator(); it.hasNext();) {
printCustomer(context,out,(Customer) it.next());
}
- tx.commit(); //提交事務
- select * from CUSTOMERS order by NAME asc;
該方法調用Session的get()方法,加載Customer對象,然後再修改Customer對象的屬性。
- tx = session.beginTransaction();
Customer c=(Customer)session.get(Customer.class,customer_id);
c.setAddress(address); //修改內存中Customer對象的address屬性
- tx.commit();
- select * from CUSTOMERS where ID=1;
- update CUSTOMERS set NAME="Tom",EMAIL="[email protected]"…ADDRESS="Beijing"…
- where ID=1;
deleteCustomer()方法
該方法調用Session的delete()方法,刪除特定的Customer對象:
- tx = session.beginTransaction();
session.delete(customer);
- tx.commit();
- delete from CUSTOMERS where ID=1;