public abstract class  SearchPage extends BaseComponent {
 
 public ReportGet parameter;

 public  void setParameter(ReportGet parameter){
  this.parameter=parameter;
 }

 public  ReportGet getParameter(){
  return this.parameter;
 }
 
 // 设置设备参数PO类
 public BasePO po=null;

 /**
  * @return the po
  */
 public BasePO getPo() {
  return po;
 }

 /**
  * @param po the po to set
  */
 public void setPo(BasePO po) {
  this.po = po;
 }
。。。。。省略，和这个错误没关系

对应的.page如下

<component-specification class="com.longcredit.KEye.app.business.report.SearchPage">  

        
    <component id="report_alert" type="Hidden">
          <binding name="value" value="ognl:parameter"/>
    </component>
       
    <component id="device_type" type="PropertySelection">
        <binding name="model" value="ognl:getSelect('1000001','action=getdeviceprototypelist')"/>
        <binding name="value" value="ognl:parameter.prototypeid"/>
    </component>
   
 <component id="date" type="TextField">
        <binding name="value" value="ognl:parameter.date"/>
    </component>
             
    <component id="searchInfo" type="Submit">
        <binding name="listener" value="listener:getLink"/>
        <binding name="parameters" value='{"action=getSummaryReportByPrototype&amp;prototypeid="+po.prototypeid+"&amp;date="+po.date+"&amp;reporttype=1","ReportIndex","updateDeviceFail"}'/>
    </component>
</component-specification>

错误如下：

org.apache.tapestry.BindingException
Unable to read OGNL expression '<parsed OGNL expression>' of $SearchPage_10@e8e8bf[ReportIndex/DateSearch]: source is null for getProperty(null, "prototypeid")
binding:	ExpressionBinding[ReportIndex/DateSearch parameter.prototypeid]
location:	context:/WEB-INF/DeviceSearchDate.jwc, line 15, column 67 10 <binding name="value" value="ognl:parameter"/> 11 </component> 12   13 <component id="device_type" type="PropertySelection"> 14 <binding name="model" value="ognl:getSelect('1000001','action=getdeviceprototypelist')"/> 15 <binding name="value" value="ognl:parameter.prototypeid"/> 16 </component> 17   18 <component id="date" type="TextField"> 19 <binding name="value" value="ognl:parameter.date"/> 20 </component>