写一个Hibernate程序的步骤：
1.导入相关jar包。
2.创建持久化类。
3.创建映射文件。 
 1  <? xml version="1.0" encoding="UTF-8" ?>
 2  <! DOCTYPE hibernate-mapping PUBLIC 
  3      "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
  4      "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd" >
 5  < hibernate-mapping  package ="com.lei.pojo" >
 6      < class  name ="User"  table ="t_user" >
 7         
 8          < id  name ="id"  column ="id" >
 9              < generator  class ="native" />
10          </ id >
11         
12          < property  name ="username"  column ="username" />
13          < property  name ="password" />
14         
15      </ class >
16  </ hibernate-mapping > 
4.创建Hibernate配置文件。
<? 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 >
        
         < property  name ="hibernate.connection.driver_class" >com.mysql.jdbc.Driver </ property >
         < property  name ="hibernate.connection.url" >jdbc:mysql:///lei </ property >
         < property  name ="hibernate.connection.username" >root </ property >
         < property  name ="hibernate.connection.password" >root </ property >
    
         < property  name ="hibernate.dialect" >org.hibernate.dialect.MySQLDialect </ property >
        
         < property  name ="hibernate.c3p0.max_size" >10 </ property >
         < property  name ="hibernate.c3p0.min_size" >2 </ property >
         < property  name ="hibernate.c3p0.timeout" >5000 </ property >
         < property  name ="hibernate.c3p0.max_statements" >100 </ property >
         < property  name ="hibernate.c3p0.idle_test_period" >3000 </ property >
         < property  name ="hibernate.c3p0.acquire_increment" >2 </ property >
         < property  name ="hibernate.c3p0.validate" >false </ property >
        
         < property  name ="current_session_context_class" >thread </ property >
        
         < property  name ="show_sql" >true </ property >
        
         < mapping  resource ="com/lei/pojo/user.hbm.xml" />
    
     </ session-factory >


</ hibernate-configuration >
5.测试运行。