SSH执行一个复合查询

Question

做一个SSH的开发，项目是飞机 订票系统。写到了查找航班的模块，要求是在页面输入目的地以及起飞的时间，然后输出同时满足输入的目的地以及起飞时间的一条航班信息。

就是这个模块，我在DAO类写了一个复合查询的方法

//按目的地，起飞时间进行查询
    public Flight queryByLocationAndTime(String f_location, String f_time) {
        // TODO Auto-generated method stub
        String hql= "from Flight as fli where fli.f_location=? and fli._time=? ";
         List<Flight> entitise=getHibernateTemplate().findByExample(hql,new String[]{"f_location","f_time"});
           if (entitise.size() > 0) {           
               Flight entity = entitise.get(0);           
             return entity;           
         }           
         return null;  
    }

然后在Service类写了逻辑处理的方法

public Flight queryFlightScheduledByLocationAndTime(String f_location,
            String f_time) {
        // TODO Auto-generated method stub
        if(f_location!=null&&f_time!=null){
            return dao.queryByLocationAndTime(f_location, f_time);
        }else{
            System.out.println("不存在目标航班");
        }
        return null;
    }

然后写了一个Action用来实现复合查询

package com.air.action;
 
import java.util.Date;
 
import com.air.po.Flight;
import com.air.service.FlightService;
import com.opensymphony.xwork2.ActionSupport;
 
public class FlightQueryTargetAction extends ActionSupport{
    private String f_location;
    private String f_time;
     
    //业务逻辑组件
    private FlightService fs;
     
    //设置业务逻辑组件
     
    public void setFlightService(FlightService fs){
        this.fs=fs;
    }
 
    public String getF_location() {
        return f_location;
    }
 
    public void setF_location(String f_location) {
        this.f_location = f_location;
    }
 
    public String getF_time() {
        return f_time;
    }
 
    public void setF_time(String f_time) {
        this.f_time = f_time;
    }
     
public String execute()throws Exception{
         
         
    //将接受的参数设置到Product实例中
    Flight f=new Flight();
    f.setF_location(f_location);
    f.setF_time(f_time);
     
    //调用业务逻辑组件保存该产品
    fs.queryFlightScheduledByLocationAndTime(f_location, f_time);
     
    return SUCCESS;
    }
}

接着写一个显示查询记录的Action

package com.air.action;
 
import java.util.Date;
import java.util.List;
 
import org.apache.struts2.ServletActionContext;
 
import com.air.po.Flight;
import com.air.service.FlightService;
import com.opensymphony.xwork2.ActionSupport;
 
public class FlightShowTargetAction extends ActionSupport{
    private String f_location;
    private String f_time;
    //业务逻辑组件
    private FlightService fs;
     
    //设置业务逻辑组件
    public void setFlightService(FlightService fs){
        this.fs=fs;
    }
     
    public String getF_location() {
        return f_location;
    }
 
    public void setF_location(String f_location) {
        this.f_location = f_location;
    }
 
    public String getF_time() {
        return f_time;
    }
 
 
 
    public void setF_time(String f_time) {
        this.f_time = f_time;
    }
 
    public String execute()throws Exception{
     
        //通过调用业务逻辑组件获得所有的产品
        List <Flight>tag=(List<Flight>) fs.queryFlightScheduledByLocationAndTime(f_location, f_time);
        //将所有产品List存储在request范围中
        ServletActionContext.getRequest().setAttribute("tag",tag);
         
        return SUCCESS;
    }
}

Struts.xml配置

<action name="flightquerytarget" class="flightQueryTargetAction">
             <!-- 定义处理结果与试图资源之间的关系 -->
                <result name="success" type="redirect">flightshowtarget.action</result>   
           </action>
            
           <action name="flightshowtarget" class="flightShowTargetAction">
             <!-- 定义处理结果与试图资源之间的关系 -->
                <result name="success">/FlightShowTarget.jsp</result>   
           </action>

applicationContext.xml的配置

<!-- 创建FlightQueryTargetAction实例 -->
    <bean id="flightQueryTargetAction" class="com.air.action.FlightQueryTargetAction" scope="prototype">
        <property name="flightService" ref="flightService"></property>
    </bean>
     
    <!-- 创建FlightShowTargetAction实例 -->
    <bean id="flightShowTargetAction" class="com.air.action.FlightShowTargetAction" scope="prototype">
        <property name="flightService" ref="flightService"></property>
    </bean>

相应的jsp：写出片段

FlightQueryTarget.jsp

<s:form action="flightquerytarget" method="post">
            <s:textfield label="航班起飞时间" name="f_time"></s:textfield>
            <s:textfield label="航班目的地" name="f_location"></s:textfield>
            <s:submit value="提交"></s:submit>
            <s:reset value="重置"></s:reset>
        </s:form>

FlightShowTarget.jsp

<s:iterator value="#request.tag" id="flight">
                <tr>
                    <td><s:property value="#flight.f_id"/></td>
                    <td><s:property value="#flight.f_time"/></td>
                    <td><s:property value="#flight.f_price"/></td>
                    <td><s:property value="#flight.f_location"/></td>
                    <td><s:property value="#flight.f_sitnum"/></td>
                    <td><a href="OrderTicket.jsp">订票</a></td>
                </tr>
            </s:iterator>

好了。萝莉啰嗦一大段。结果就是出错了！
HTTP Status 500 - Unknown entity: from Flight as fli where fli.f_location=? and fli._time=? ; nested exception is org.hibernate.MappingException: Unknown entity: from Flight as fli where fli.f_location=? and fli._time=?

求大神解答，很重要的项目。新手自己从零动手，不容易。求解答，不求打劫

Answer 1

补充一点，po类和Flight,hbm.xml等配置不会出现问题的，因为已经测试过输出全部航班信息。所以Hibernate持久化那边应该没问题。。。