Struts2.3.4+Hibernate4.2.4+Mysql6.0整合

<filter>
       <filter-name>struts2</filter-name>    
　　　　<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
      <filter-name>struts2</filter-name>
      <url-pattern>/* </url-pattern>
</filter-mapping>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
　　　　 <!-- 连接数据库的用户名和密码 -->
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">password1!</property>
　　　　　<!--mysql数据库驱动-->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <!-- url，并且设置编码格式，其中&amp;是html中对&的转义  -->
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/数据库名称?useUnicode=true&amp;characterEncoding=UTF-8</property>
        <!--设置方言为mysql -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
　　　   <!-- 执行操作时，打印sql语句 -->
        <property name="show_sql">true</property>
        <!-- 格式化输出的sql语句 -->
        <property name="format_sql">true</property>
        <!-- 表的生成策略 -->
        <property name="hbm2ddl.auto">update</property>
　　　　　<!-- 采用getCurrentSession的方式获取session对象时，此处需要加上这句话 -->
        <property name="hibernate.current_session_context_class">thread</property> 
    </session-factory>
</hibernate-configuration>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
    <!-- 开发者模式打开，便于调试-->
    <constant name="struts.devMode" value="true"></constant>
    <package name="default" namespace="/" extends="struts-default">
</struts>  

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2016-7-23 10:35:39 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
    <!-- class的name属性值一定要从包名开始引用 -->
    <class name="com.imooc.entity.Student" table="student">
        <id type="java.lang.String" name="sid" column="SID" length="8">
　　　　　　　<!--主键增长策略，assigned表示以自定义的方式增加主键，而不是由数据库自动生成-->
            <generator class="assigned"></generator>
        </id>


         <property name="sname" type="java.lang.String">
            <column name="SNAME" />
        </property>
        
        <property name="sgender" type="java.lang.String">
            <column name="SGENDER" />
        </property>
      
    　　<!-- type类型，可以写hibernate映射类型date(只显示年月日) time(只显示时间) timestamp(年月日时分秒)，也可以写Java对应的类型：java.util.Date -->
        <property name="sbirthday" type="date">
            <column name="SBIRTHDAY" />
        </property>
        
        <property name="saddress" type="java.lang.String">
            <column name="SADDRESS" />
        </property>
        
    </class>
</hibernate-mapping>

<session-factory>
...
<mapping resource="com/imooc/entity/Student.hbm.xml"/>
<mapping resource="com/imooc/entity/User.hbm.xml"/>
...
</session-factory>

public class SessionFactoryUtil {

    private static SessionFactory sessionFactory;
    // 单例模式
    private SessionFactoryUtil() {
    }

    public static SessionFactory getSessionFactory() {
        if (sessionFactory == null) {
            // 获取配置信息
            Configuration configuration = new Configuration().configure();
            // 获取服务注册对象
            ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
                    .applySettings(configuration.getProperties())
                    .buildServiceRegistry();
            sessionFactory = configuration.buildSessionFactory(serviceRegistry);
        }
        return sessionFactory;
    }
}

Session session = SessionFactoryUtil.getSessionFactory()
                    .getCurrentSession();
transaction = session.beginTransaction();

//这种方式的前提是，在实体类student中必须存在包含选项列的构造函数才可以
String hql = "SELECT new Student(sid, sname, sgender, sbirthday, saddress) FROM Student";
List<Student> s = query.list();

//String hql = "SELECT new List(sid, sname, sgender, sbirthday, saddress) FROM Student";
//List<List> lists = query.list();

//String hql = "SELECT new Map(sid, sname, sgender, sbirthday, saddress) FROM Student";
//List<Map> maps= query.list();

//默认
//String hql = "SELECT sid, sname, sgender, sbirthday, saddress FROM Student";
//List<Object[]> lists = query.list();

<form name="loginForm" action="<%=path%>/user/User_login.action" method="post">

解释一下<%=path%>后面的user是什么？User_login又是什么？
首先，user代表namespace。后面的User_login采用通配符的方式匹配action

<package name="student" namespace="/student" extends="struts-default">
        <action name="*_*" class="com.imooc.action.{1}Action" method="{2}">
            <result name="list_success">/student/Students_query_success.jsp</result>
            <result name="list_failer">/student/Students_query_success.jsp</result>
            <result name="add_success">/student/Students_add_success.jsp</result>
            <result name="modify_middle">/student/Students_modify.jsp</result>
            <result name="save_success">/student/Students_modify_success.jsp</result>
            <result name="delete_success" type="chain">Student_query</result><!-- 注意路径。type中chain代表页面跳转到其他的请求。不可以跳转到某一个页面 -->
        </action>
</package>
这里想说，在result中跳转到其他的action，type="chain". 如果由result中跳转到其他的jsp页面，默认type="dispatcher"