freemarker 一些错误整理

1.关于boolean的配置
freemarker中输出时可以使用这种方式输出${xxx?string("true","flase")}
当xxx为true时显示字符串true,否则为字符串false，当然true,false字符串也可以换成其他字符串，比如yes和no。

单纯的输出true/false,可以这样写 ${xxx?c}

 "isBundle": "${APIProfileMaintenanceService.response.body.isBundle?c}" 

2.关于对象为空的配置
有时候请求或者响应里，如果有一个对象会为空，要对对象进行null的判断，不然会抛异常。
如下所示
需要用<#if ()??> 括号内填写条件

{
   "body":
   {
      "productOfferingPrice":
      {
          <#if (APIOfferMaintenanceService.response.body.productOfferingPrice)??>
         "unitOfMeasure":"${APIOfferMaintenanceService.response.body.productOfferingPrice.unitOfMeasure!}"
          
      }
   }
}

3.For "." left-hand operand: Expected a hash, but this has evaluated to a sequence (wrapper: f.t.SimpleSequence):

==> APIBillingMaintenanceService.response.body.transcationList [in template "sid-ED4B5F2B-1A2F-4A0F-80E4-8EEB0DD65CA9" at line 1, column 2308]
这个错误一般是模板内部写的有问题，比如我这个，

{
      "body":
      {
            "transcationList":
            [
                  <#if  (APIBillingMaintenanceService.response.body.transcationList)??>
                  <#list    APIBillingMaintenanceService.response.body.transcationList  as  transcationList>
                  {    
                        "operationCharacteristic":
                        [
                          <#if  (APIBillingMaintenanceService.response.body.transcationList.operationCharacteristic)??>
                           <#list  APIBillingMaintenanceService.response.body.transcationList.operationCharacteristic  as  operationCharacteristic>
                              {
                                    "name":"${operationCharacteristic.name!}",
                                    "value":"${operationCharacteristic.value!}"
                              }
                          
                          
                        ]

                  
                  
       ]
   }

}

外部list起了别名，内部List就不能从最开始的APIBillingMaintenanceService.response.body.transcationList开始，更改如下

{
      "body":
      {
            "transcationList":
            [
                  <#if  (APIBillingMaintenanceService.response.body.transcationList)??>
                  <#list    APIBillingMaintenanceService.response.body.transcationList  as  transcationList>
                  {    
                        "operationCharacteristic":
                        [
                          <#if  (transcationList.operationCharacteristic)??>
                           <#list  transcationList.operationCharacteristic  as  operationCharacteristic>
                              {
                                    "name":"${operationCharacteristic.name!}",
                                    "value":"${operationCharacteristic.value!}"
                              }
                          
                          
                        ]

                  
                  
       ]

   }

}

4.freemarker处理List,process之后为空

{"BillingAccountList":[]}

如上，这是freemarker处理之后显示的内容，list里的所有东西都丢了，模板如下

{
   "body":
   {
      "BillingAccountList":
      [
         <#if (APIProfileQueryService.response.body.BillingAccountList)??>
          <#list APIProfileQueryService.response.body.BillingAccountList as BillingAccountList>
         {
            "defaultPaymentMethod":
            {
               "id":"${BillingAccountList.defaultPaymentMethod.id!}",
               "type":"${BillingAccountList.defaultPaymentMethod.type!}"
            }
             
          
            
      ]

   }

}

经过测试，将所有的BillingAccountList改成billingAccountList，就有映射值了

{
   "body":
   {
      "billingAccountList":
      [
         <#if (APIProfileQueryService.response.body.billingAccountList)??>
          <#list APIProfileQueryService.response.body.billingAccountList as billingAccountList>
         {
            "defaultPaymentMethod":
            {
               "id":"${billingAccountList.defaultPaymentMethod.id!}",
               "type":"${billingAccountList.defaultPaymentMethod.type!}"
            }
             
          
            
      ]

   }

}

暂时原理未知，没有细看源码