初次使用hibernate

1、在servlet中调用hibernate中的方法时，必须将hibernate中的包放在WEB-INF下的lib文件夹下，否则会报java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter异常。
2、出现h2.org.driver异常，是因为缺少h2-1.3.164.jar包造成的。
3、hibernate.cfg.xml配置文件

 

<hibernate-configuration>
  <session-factory>
    <property name="hibernate.hbm2ddl.auto">updateproperty>
    
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driverproperty>
    
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/nginx_reportproperty>
    
    <property name="hibernate.connection.username">rootproperty>
    
    <property name="hibernate.connection.password">123456property>
    
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialectproperty>
    
    <mapping resource="com/zjlao/createtable/UrlCount.hbm.xml" />
  session-factory>
hibernate-configuration>

此配置文件是由org.hibernate.cfg.Configuration自动获取的，必须放在src目录下

4、UrlCount.hbm.xml配置文件

<hibernate-mapping package="com/zjlao/createtable">
    
    <class name="com.zjlao.createtable.UrlCount" table="urlcount_20170308">
        <id name="url">
            
            <generator class="uuid">generator>
        id>
        <property name="sum">property>
    class>


hibernate-mapping>

id必须为UrlCount类中的字段
5、UrlCount类

package com.zjlao.createtable;

public class UrlCount {
    private String url;
    private String sum;
    public String getSum() {
        return sum;
    }
    public void setSum(String sum) {
        this.sum = sum;
    }
    public String getUrl() {
        return url;
    }
    public void setUrl(String url) {
        this.url = url;
    }
}

6、创建表

package com.zjlao.createtable;

import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

/*
 * 将hbm生成ddl
 */

public class ExportDB {
    public boolean createTable(){
        //默认读取hibernate.cfg.xml文件
        Configuration configuration = new Configuration().configure();
        //生成并输出sql到文件(当前文件)和数据库
        SchemaExport schemaExport = new SchemaExport(configuration);
        schemaExport.create(true,true);
        return true;
    }
    public static void main(String[] args) {
        ExportDB exportDB = new ExportDB();
        exportDB.createTable();
    }
}

将hibernate.cfg.xml,UrlCount.hbm.xml配置完成，UrlCount，
ExportDB类写好，运行ExportDB就能在数据库中创建urlcount_20170308表