ssh项目中一个控制器抛出java.lang.NullPointerException异常，搞了好几天不知如何解决(急)!!!!![上次操作失误,这次补过]

二、CreateOrderItemAction代码如下：
/**
*
*/
package com.iwtxokhtd.action;import java.util.Date;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;import com.iwtxokhtd.dao.CreateOrderItemDao;
import com.iwtxokhtd.form.OrderItemBeanForm;/**
* @author iwtxokhtd
*
*/
public class CreateOrderItemAction extends Action{ //航班日程安排dao
private CreateOrderItemDao itemdao; @Override
public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
// TODO Auto-generated method stub
//错误消息对象
ActionMessages errors=new ActionMessages();

//从模型中获取数据
String id=(String)((OrderItemBeanForm)form).getId();
String year=(String)((OrderItemBeanForm)form).getYear();
String month=(String)((OrderItemBeanForm)form).getMonth();
String day=(String)((OrderItemBeanForm)form).getDay();

//转换字符格式

  id=new String(id.getBytes("ISO-8859-1"),"gb2312");
  year=new String(year.getBytes("ISO-8859-1"),"gb2312");
      month=new String(month.getBytes("ISO-8859-1"),"gb2312");
      day=new String(day.getBytes("ISO-8859-1"),"gb2312");
  Long lid=new Long(Long.parseLong(id));
          Date date=new Date(Integer.parseInt(year),Integer.parseInt(month),Integer.parseInt(day));
           //若id,year,month,day为空，则报错
     if(id==null||year==null||month==null||day==null)
     {
     errors.add("fail_1",new ActionMessage("CreateOrderItemAction.c"));
     saveErrors(request,errors);
     return mapping.getInputForward();
     }

//保存新的航班日程安排
if(!itemdao.CreateOrderItem(lid, date))
{
errors.add("fail_2", new ActionMessage("CreateOrderItemAction.a"));
saveErrors(request,errors);

}
else
{
errors.add("succeed_1",new ActionMessage("CreateOrderItemAction.b"));
saveErrors(request,errors);
}

return mapping.findForward("createok");

}
public CreateOrderItemDao getItemdao() {
return itemdao;
} public void setItemdao(CreateOrderItemDao itemdao) {
this.itemdao = itemdao;
}
}

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三、对应的DAO代码如下：
/**
* 管理员安排航班日程操作
*/
package com.iwtxokhtd.dao;import java.util.Date;import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;import com.iwtxokhtd.orm.Flight;
import com.iwtxokhtd.orm.OrderItem;/**
* @author iwtxokhtd
*
*/
public class CreateOrderItemDao extends HibernateDaoSupport { //Log4j日志对象
private static final Log log=LogFactory.getLog(CreateOrderItemDao.class);

//初始化dao
protected void initDao()
{
//这里我们为空实现
}

//判断航班日程安排是否成功
public boolean CreateOrderItem(long flightid,Date date)
{
//Flight实体对象
Flight flight=(Flight) this.getHibernateTemplate().load(Flight.class, flightid);

//订单实体对象
OrderItem item=new OrderItem();

//保存订单设置
item.setFlight(flight);
item.setDate(date);

//执行保存操作
try {

this.getHibernateTemplate().save(item);
return true;//保存成功
} catch (Exception e) {
// TODO: handle exception
//报告异常
log.error(e.getMessage());
return false;
}
}
}
四、对应的CreateOrderItem.JSP如下：
<%@ page language="java" import="java.util.List" pageEncoding="gb2312"%>
<%@ page import="java.util.Iterator" %>
<%@ page import="com.iwtxokhtd.orm.Flight" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %><%
  String tmp=(String)session.getAttribute("curr_admin");
  if(tmp==null)
  {

%>
  <jsp:forward page="/index.jsp"></jsp:forward>
  <%
   }
   List allFlights=(List)session.getAttribute("items");
   Iterator it=(Iterator)allFlights.iterator();
   Flight flight=null;
   String id=null,str=null,year=null,month=null,day=null;
   int y=2008,m=4,d=14;
   %>
<html>
  <head>
   <title><bean:message key="admin.manage.page"/></title>
  </head>

  <body>
   <html:form action="/createOrderItem.do">
   <table width="97%" height="495"  border="0">
    <tr>
    <td height="27" align="center">
    <table width="68%" height="38"  border="0">
      <tr>
        <td align="center" bgcolor="#0099FF"><bean:message key="admin.system"/></td>
      </tr>
    </table>
    </td>
  </tr>
  <tr>
    <td height="17" align="center"><hr></td>
  </tr>
  <tr>
  <td align="center"><font color="red"><html:errors/></font></td>
  </tr>
  <tr>
      <td height="280" align="center">
      <table width="66%" height="201"  border="0">
      <tr>
        <td width="33%" height="73" align="center"><bean:message key="select.flight"/></td>
         <td width="67%">
         <html:select property="id" multiple="false" size="1">
         <%
           while(it.hasNext())
           {
           flight=(Flight)it.next();
           id=flight.getId()+"";
           str=flight.getFlight_no();
          %>
          <html:option value="<%=id%>"><%=str%></html:option>
          <%
          }
           %>
         </html:select>
         </td>
      </tr>
      <tr>
          <td height="69" align="center"><bean:message key="asign.flight.date"/></td>
          <td align="center">
          <table width="95%"  border="0">
          <tr>
          <td height="34">
          <html:select property="year" multiple="false" size="1">
           <%
             while(y<=2020)
             {
               year=""+y;
           %>
           <html:option value="<%=year%>"></html:option>
           <%
             y++;
             }
            %>
          </html:select>
          <bean:message key="year"/>
          </td>
          <td>
            <html:select property="month" multiple="false" size="1">
<%
while(m <= 12){
month = ""+m;
%>
<html:option value="<%=month%>"></html:option>
<%
m ++;
}
%>
</html:select>
<bean:message key="month"/>
          </td>
          <td>
             <html:select property="day" multiple="false" size="1">
<%
while(d <= 31){
day = ""+d;
%>
<html:option value="<%=day%>"></html:option>
<%
d++;
}
%>
</html:select>
<bean:message key="day"/>
          </td>
          </tr>
          </table>
          </td>
      </tr>
      <tr>
        <td colspan="2" align="center">
        <table width="58%" height="37"  border="0" cellspacing="0">
          <tr align="center">
          <td><html:submit><bean:message key="queding"/></html:submit></td>
          </tr>
        </table>
        </td>
       </tr>
    </table>
    </td>
      </tr>
    </table>
      </td>
  </tr>
   </table>
   </html:form>
  </body>
</html>
五、对应的Bean如下：
/*
* Generated by MyEclipse Struts
* Template path: templates/java/JavaClass.vtl
*/
package com.iwtxokhtd.form;import javax.servlet.http.HttpServletRequest;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;/**
* MyEclipse Struts
* Creation date: 04-14-2008
*
* XDoclet definition:
* @struts.form name="orderItemBeanForm"
*/
public class OrderItemBeanForm extends ActionForm {
/*
* Generated fields
*/ /**
*
*/
private static final long serialVersionUID = 1L; /** month property */
private String month; /** day property */
private String day; /** year property */
private String year; /** id property */
private String id; /*
* Generated Methods
*/ /**
* Method validate
* @param mapping
* @param request
* @return ActionErrors
*/
public ActionErrors validate(ActionMapping mapping,
HttpServletRequest request) {
// TODO Auto-generated method stub
return null;
} /**
* Method reset
* @param mapping
* @param request
*/
public void reset(ActionMapping mapping, HttpServletRequest request) {
// TODO Auto-generated method stub
} /**
* Returns the month.
* @return String
*/
public String getMonth() {
return month;
} /**
* Set the month.
* @param month The month to set
*/
public void setMonth(String month) {
this.month = month;
} /**
* Returns the day.
* @return String
*/
public String getDay() {
return day;
} /**
* Set the day.
* @param day The day to set
*/
public void setDay(String day) {
this.day = day;
} /**
* Returns the year.
* @return String
*/
public String getYear() {
return year;
} /**
* Set the year.
* @param year The year to set
*/
public void setYear(String year) {
this.year = year;
} /**
* Returns the id.
* @return String
*/
public String getId() {
return id;
} /**
* Set the id.
* @param id The id to set
*/
public void setId(String id) {
this.id = id;
}
}
六、对应的持久化类如下：
/**
* 航班日程持久化类
*/
package com.iwtxokhtd.orm;import java.util.Date;/**
* @author iwtxokhtd
*
*/
public class OrderItem { //对应数据库的ID字段为主键
private long id;

//Flight持久类对象
private Flight flight;
//对应数据库Date字段,航班日程安排
private Date date; //生成相应的setter和getter方法

public Date getDate() {
return date;
} public void setDate(Date date) {
this.date = date;
} public Flight getFlight() {
return flight;
} public void setFlight(Flight flight) {
this.flight = flight;
} public long getId() {
return id;
} public void setId(long id) {
this.id = id;
}}
七、ORM映射文件OrderItem.hbm.xml文件:
<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
                            "-//Hibernate/Hibernate Mapping DTD//EN"
                            "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>
     <class name="com.iwtxokhtd.orm.OrderItem" table="orderitems" lazy="false">
         <id name="id" column="id" type="long">
           <generator class="increment"/>
         </id>

         <property name="date" column="date" type="java.sql.Date" not-null="true"/>

         <many-to-one
            name="flight"
            column="flight_id"
            class="com.iwtxokhtd.orm.Flight"
            not-null="true"/>
     </class>
</hibernate-mapping>
以及Flight.hbm.xml文件:
<?xml version="1.0" encoding='UTF-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
                            "-//Hibernate/Hibernate Mapping DTD//EN"
                            "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >

<hibernate-mapping>
     <class name="com.iwtxokhtd.orm.Flight" table="flights" lazy="false">
         <id name="id" column="id" type="long">
           <generator class="increment"/>
         </id>

         <property name="flight_no" column="flight_no" type="string" not-null="true"/>
         <property name="start_place" column="start_place" type="string" not-null="true"/>
         <property name="end_place" column="end_place" type="string" not-null="true"/>
         <property name="time" column="time" type="int" not-null="true"/>
         <property name="price" column="price" type="double" not-null="true"/>
     </class>
</hibernate-mapping>
八、Flight持久化类:
/**
* 航班信息持久化类
*/
package com.iwtxokhtd.orm;import java.io.Serializable;/**
* @author iwtxokhtd
*
*/
public class Flight implements Serializable{ /**
*
*/
private static final long serialVersionUID = 1L;
private long id;//对应数据库ID字段为主键
private String flight_no;//航班编号
private String start_place;//起飞地
private String end_place;//到达目的地
private int time;//整个航程的耗时
private double price;//航班机票价格

//生成相应的setter和getter方法

public String getEnd_place() {
return end_place;
}
public void setEnd_place(String end_place) {
this.end_place = end_place;
}
public String getFlight_no() {
return flight_no;
}
public void setFlight_no(String flight_no) {
this.flight_no = flight_no;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public String getStart_place() {
return start_place;
}
public void setStart_place(String start_place) {
this.start_place = start_place;
}
public int getTime() {
return time;
}
public void setTime(int time) {
this.time = time;
}

}
九、Struts-config.xml位于/WEB-INF下:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://struts.apache.org/dtds/struts-config_1_2.dtd"><struts-config>
  <data-sources />
  <form-beans >
    <form-bean name="logUserForm" type="com.iwtxokhtd.form.LogUserForm" />
    <form-bean name="adminUserForm" type="com.iwtxokhtd.form.AdminUserForm" />
    <form-bean name="regUserForm" type="com.iwtxokhtd.form.RegUserForm" />
    <form-bean name="manageUserForm" type="com.iwtxokhtd.form.ManageUserForm" />
    <form-bean name="flightBeanForm" type="com.iwtxokhtd.form.FlightBeanForm" />
    <form-bean name="orderItemBeanForm" type="com.iwtxokhtd.form.OrderItemBeanForm" />  </form-beans>  <global-exceptions />
  <global-forwards />
  <action-mappings>
    <action
      attribute="logUserForm"
      input="/index.jsp"
      name="logUserForm"
      path="/log"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy"
      validate="true">
      <forward name="login" path="/view/content.jsp" />
    </action>
    <action
      attribute="adminUserForm"
      input="/admin.jsp"
      name="adminUserForm"
      path="/adminLog"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="login" path="/view/admincontent.jsp" />
    </action>
    <action
      attribute="regUserForm"
      input="/view/reg.jsp"
      name="regUserForm"
      path="/reg"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="regin" path="/view/regok.jsp" />
    </action>
    <action
      path="/retrieve"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy"
      validate="false">
      <forward name="retrok" path="/view/shoppingcar.jsp" />
    </action>
    <action
      input="/view/purchase.jsp"
      path="/purchase"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="purchaok" path="/view/purchaseok.jsp" />
    </action>
    <action
      path="/purchaseReturn"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="return" path="/view/content.jsp" />
    </action>
    <action
      path="/indexReturn"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy"
      validate="false">
      <forward name="return" path="/index.jsp" />
    </action>
    <action
      attribute="manageUserForm"
      input="/view/PersonInfo.jsp"
      name="manageUserForm"
      path="/manageUserAct"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="manageok" path="/view/content.jsp" />
    </action>
    <action
      attribute="flightBeanForm"
      input="/view/CreateFlight.jsp"
      name="flightBeanForm"
      path="/createFlight"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy" />
    <action
      input="/view/admincontent.jsp"
      path="/readFlight"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="readok" path="/view/CreateOrderItem.jsp" />
    </action>
    <action
      attribute="orderItemBeanForm"
      input="/view/admincontent.jsp"
      name="orderItemBeanForm"
      path="/createOrderItem"
      scope="request"
      type="org.springframework.web.struts.DelegatingActionProxy">
      <forward name="createok" path="/view/admincontent.jsp" />
    </action>

  </action-mappings>
<controller processorClass="org.springframework.web.struts.DelegatingRequestProcessor" />
  <message-resources parameter="com.iwtxokhtd.struts.ApplicationResources" null="false" /><plug-in className="org.springframework.web.struts.ContextLoaderPlugIn">
<set-property property="contextConfigLocation" value="/WEB-INF/applicationContext.xml"/>
</plug-in>
</struts-config>
applicationContext.xml位于/WEB-INF下:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"><beans>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref bean="dataSource" />
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
    <prop key="hibernate.show_sql">true</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>com/iwtxokhtd/orm/Admin.hbm.xml</value>
<value>com/iwtxokhtd/orm/Flight.hbm.xml</value>
<value>com/iwtxokhtd/orm/Order.hbm.xml</value>
<value>com/iwtxokhtd/orm/OrderItem.hbm.xml</value>
<value>com/iwtxokhtd/orm/User.hbm.xml</value>
</list>
</property>
</bean>
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName">
<value>org.gjt.mm.mysql.Driver</value>
</property>
<property name="url">
<value>jdbc:mysql://localhost/flight</value>
</property>
<property name="username">
<value>root</value>
</property>
<property name="password">
<value>localhost</value>
</property>
</bean>
<bean id="transactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="userDAOProxy"
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager">
<ref bean="transactionManager" />
</property>
<property name="target">
<list>
<ref local="userdao" />
<ref local="adminlog" />
<ref local="regdao" />
<ref local="cardao" />
<ref local="retrievedao" />
<ref local="purchasedao" />
<ref local="managedao" />
<ref local="flightdao" />
<ref local="readdao" />
<ref local="itemdao" />
</list>
</property>
<property name="transactionAttributes">
<props>
<prop key="insert*">PROPAGATION_REQUIRED</prop>
<prop key="get*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="is*">PROPAGATION_REQUIRED,readOnly</prop>
</props>
</property>
</bean>

<bean id="hibernateTemplate"
class="org.springframework.orm.hibernate3.HibernateTemplate">
<property name="sessionFactory">
<ref bean="sessionFactory" />
</property>
</bean>

<bean id="userdao" class="com.iwtxokhtd.dao.LogUserDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="adminlog" class="com.iwtxokhtd.dao.LogAdminDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="regdao" class="com.iwtxokhtd.dao.RegUserDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="cardao" class="com.iwtxokhtd.dao.ShoppingCarDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="retrievedao" class="com.iwtxokhtd.dao.RetrieveTicketsDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="purchasedao" class="com.iwtxokhtd.dao.PurchaseDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="managedao" class="com.iwtxokhtd.dao.ManageUserDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="flightdao" class="com.iwtxokhtd.dao.CreateFlightDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="readdao" class="com.iwtxokhtd.dao.ReadFlightDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean id="itemdao" class="com.iwtxokhtd.dao.CreateOrderItemDao">
<property name="sessionFactory">
<ref local="sessionFactory" />
</property>
</bean>
<bean name="/log" class="com.iwtxokhtd.action.LogAction"
singleton="false">
<property name="userdao">
<ref bean="userdao" />
</property>
</bean>
<bean name="/adminLog" class="com.iwtxokhtd.action.AdminLogAction"
singleton="false">
<property name="adminlog">
<ref bean="adminlog" />
</property>
</bean>
<bean name="/reg" class="com.iwtxokhtd.action.RegAction"
singleton="false">
<property name="regdao">
<ref bean="regdao" />
</property>
</bean>
<bean name="/retrieve" class="com.iwtxokhtd.action.RetrieveTicketsAction"
singleton="false">
<property name="retrievedao">
<ref bean="retrievedao" />
</property>
</bean>
<bean name="/purchase" class="com.iwtxokhtd.action.PurchaseAction"
singleton="false">
<property name="purchasedao">
<ref bean="purchasedao" />
</property>
</bean>
<bean name="/purchaseReturn"
class="com.iwtxokhtd.action.PurchaseReturnAction"
singleton="false">
</bean>
<bean name="/indexReturn"
class="com.iwtxokhtd.action.IndexReturnAction"
singleton="false">
</bean>
<bean name="/manageUserAct"
class="com.iwtxokhtd.action.ManageUserAction"
singleton="false" >
<property name="managedao">
<ref bean="managedao" />
</property>
</bean>
<bean name="/createFlight"
class="com.iwtxokhtd.action.CreateFlightAction"
singleton="false" >
<property name="flightdao">
<ref bean="flightdao" />
</property>
</bean>
<bean name="/readFlight"
class="com.iwtxokhtd.action.ReadFlightAction"
singleton="false" >
<property name="readdao">
<ref bean="readdao" />
</property>
</bean>
<bean name="/createOrderItem"
class="com.iwtxokhtd.action.CreateOrderItemAction"
singleton="false">
<property name="itemdao">
<ref bean="itemdao" />
</property>
</bean>
<bean id="shopcar" class="com.iwtxokhtd.business.ShoppingCar"
singleton="false">
<property name="cardao">
<ref bean="cardao" />
</property>
</bean>
<bean id="purchase" class="com.iwtxokhtd.business.Purchase"
singleton="false">
<property name="purchasedao">
<ref bean="purchasedao" />
</property>
</bean></beans>
十、orderitems表：
id(pk) bigint 20  auto_increment
flight_id bigint 20 not null
date datetime 19 not null
flights表:
id(pk)bigint 20 auto_increment
flight_no varchar 20 not null
start_place varchar 20 not null
end_place varchar 20 not null
time int 11 not null
price double 22 not null
空指针异常，你看看你要操作的javabean中哪个属性的值为空不就可以了？
就是OrderItemBeanForm中的id,year,month,day四个属性的值为空，这个我知道，就是解决不了
这四个属性值是通过JSP中的select手动选择值(见上面的CreateOrderItem.jsp),相关联的是:OrderItemBeanForm、OrderItem.hbm.xml,OrderItem等，在上面全部贴出来了
CreateOrderItemAction.java:47表示CreateOrderItemAction.java的47行出错，我贴过去看了一下好像是id=new String(id.getBytes("ISO-8859-1"),"gb2312");这里，不知道是不是准确。
String id=(String)((OrderItemBeanForm)form).getId();
之后如果id是null，那么id.getBytes("ISO-8859-1")就会抛出空指针异常，要么保证id不是null，要么加上if(id != null)的判断
//保存新的航班日程安排
if(!itemdao.CreateOrderItem(lid, date))
出错。
是不是取值没有取到？？