Hibernate学习（一）创建数据表

（1）生成数据库表的创建：

             // 默认读取hibernate.cfg.xml文件
             Configuration cfg = new Configuration().configure();  

             // 生成并输出sql到文件（当前目录）和数据库
             SchemaExport export = new SchemaExport(cfg);  

             // 创建表结构，第一个true 表示在控制台打印sql语句，第二个true 表示导入sql语句到数据库
             export.create(true, true); 

(2)Hibernate.cfg.xml文件

 <?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">

 <hibernate-configuration>
 <session-factory>
     <!-- 必须去配置的属性 -->
     <!-- 配置数据库连接的基本信息: -->
     <property name="hibernate.connection.driver_class">
         com.mysql.jdbc.Driver
     </property>
     <property name="hibernate.connection.url">
         jdbc:mysql:///hibernate
     </property>
     <property name="hibernate.connection.username">root</property>
     <property name="hibernate.connection.password">123456</property>
     <!-- Hibernate的方言 -->
     <!-- 生成底层SQL不同的 -->
     <property name="hibernate.dialect">
         org.hibernate.dialect.MySQLDialect
     </property>

     <!-- 可选的属性 -->
     <!-- 显示SQL -->
     <property name="hibernate.show_sql">true</property>
     <!-- 格式化SQL -->
     <property name="hibernate.format_sql">true</property>
     <!-- hbm:映射 to DDL: create drop alter -->
     <property name="hibernate.hbm2ddl.auto">update</property>

     <!-- 通知Hibernate加载那些映射文件 -->
     <mapping resource="cn/lonecloud/domain/User.hbm.xml" />
     <mapping resource="cn/lonecloud/domain/Customer.hbm.xml" />
     <mapping resource="cn/lonecloud/domain/Order.hbm.xml" />

 </session-factory>
 </hibernate-configuration>

(3)log4j.properties文件

 ### direct log messages to stdout ###
 log4j.appender.stdout=org.apache.log4j.ConsoleAppender
 log4j.appender.stdout.Target=System.err
 log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
 log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

 ### direct messages to file mylog.log ###
 log4j.appender.file=org.apache.log4j.FileAppender
 log4j.appender.file.File=c\:mylog.log
 log4j.appender.file.layout=org.apache.log4j.PatternLayout
 log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

 ### set log levels - for more verbose logging change 'info' to 'debug' ###

 log4j.rootLogger=off, stdout 

（4）User.java

 package cn.lonecloud.domain;

 import java.io.Serializable;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.Date;

 public class User implements Serializable,Cloneable {

       private String id;
       private String name;
       private String password;
       private Date birthday;
       public User(){
           System.out.println("user");
       }
     public String getId() {
         return id;
     }
     public void setId(String id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getPassword() {
         return password;

     }
     public void setPassword(String password) {
         this.password = password;
     }
     public Date getBirthday() {
         return birthday;
     }
     public void setBirthday(Date birthday) {
         this.birthday = birthday;
     }
     @Override
     public  Object clone() throws CloneNotSupportedException {
          Class clazz = User.class;
          User user =null;
          try {
              user = (User)clazz.newInstance();
              /*user.setBirthday(this.birthday);
              user.setId(this.id);
              user.setPassword(this.password);
              user.setName(this.name);*/
              Field[] declaredFields = clazz.getDeclaredFields();
              for(Field field :declaredFields){
                   Class<?> parameterTypes = field.getType();
                   String fieldName = field.getName();
                   String methodName = "set"+fieldName.substring(0,1).toUpperCase()+field.getName().substring(1);
                   Method method = clazz.getDeclaredMethod(methodName, parameterTypes);
                   field.setAccessible(true);
                   method.invoke(user,field.get(this));
              }
              return user;
         } catch (Exception e) {
             e.printStackTrace();
         }
          return null;
     }

 }

(5).user.hbm.xml

 <?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 package="cn.lonecloud.domain" >
     <class name="User" table="t_user"  select-before-update="false">
         <!--hibernate为我们生成主键id-->
         <id name="id">
             <generator class="uuid" />
         </id>  

         <!--默认把类的变量映射为相同名字的表列，当然我们使用column属性修改表字段-->
         <property name="name" column="names"></property>
         <property name="password"></property>
         <property name="birthday" type="date"></property> <!--当为日期类型的时候标明date类型-->

     </class>
 </hibernate-mapping>

6.Customer.java

 package cn.lonecloud.domain;

 import java.io.Serializable;
 import java.util.HashSet;
 import java.util.Set;

 public class Customer implements Serializable {

     private String id;

     private String customerName;

     private Set<Order> orders = new HashSet<Order>();

     public String getId() {
         return id;
     }

     public void setId(String id) {
         this.id = id;
     }

     public String getCustomerName() {
         return customerName;
     }

     public void setCustomerName(String customerName) {
         this.customerName = customerName;
     }

     public Set<Order> getOrders() {
         return orders;
     }

     public void setOrders(Set<Order> orders) {
         this.orders = orders;
     }

 }

7.Customer.hbm.xml

 <?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 package="cn.lonecloud.domain" >
     <class name="Customer" table="t_customer" lazy="true">
         <!--hibernate为我们生成主键id-->
         <id name="id">
             <generator class="uuid" />
         </id>  

         <!--默认把类的变量映射为相同名字的表列，当然我们使用column属性修改表字段-->
         <property name="customerName" column="customerName"></property>
         <set name="orders" lazy="extra" fetch="join" cascade="all-delete-orphan">  <!-- lazy fetch -->
             <key column="customer_id"></key>
             <one-to-many class="cn.lonecloud.domain.Order"/>
         </set>

     </class>
 </hibernate-mapping>

8.Order.java

 package cn.lonecloud.domain;

 import java.io.Serializable;

 public class Order  implements Serializable{

      private String id;

      private String orderNumber;

      private float price;

      private Customer customer;

     public Customer getCustomer() {
         return customer;
     }

     public void setCustomer(Customer customer) {
         this.customer = customer;
     }

     public String getId() {
         return id;
     }

     public void setId(String id) {
         this.id = id;
     }

     public String getOrderNumber() {
         return orderNumber;
     }

     public void setOrderNumber(String orderNumber) {
         this.orderNumber = orderNumber;
     }

     public float getPrice() {
         return price;
     }

     public void setPrice(float price) {
         this.price = price;
     }

 }

9.Order.hbm.xml

 <?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 package="cn.lonecloud.domain" >
     <class name="Order" table="t_order" >
         <!--hibernate为我们生成主键id-->
         <id name="id">
             <generator class="uuid" />
         </id>  

         <!--默认把类的变量映射为相同名字的表列，当然我们使用column属性修改表字段-->
         <property name="orderNumber" column="orderNumber"></property>
         <property name="price" column="price"></property>
         <many-to-one name="customer" class="cn.lonecloud.domain.Customer">
            <column name="customer_id"/>
         </many-to-one>
     </class>
 </hibernate-mapping>