存储键值对以供WSO2ESB代理服务中引用

Question

我使用peopleHr连接器以以下格式获取json数据，其中包含大约500名员工的详细信息：

{
  "Result": [
    {
      "EmployeeId": {
        "DisplayValue": "UK20900"
      },
      "Title": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "FirstName": {
        "DisplayValue": "Riyafa",
        "FieldHistory": []
      },
      "LastName": {
        "DisplayValue": "Abdul Hameed",
        "FieldHistory": []
      },
      "OtherName": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "KnownAs": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "EmailId": {
        "DisplayValue": "[e-mail]",
        "FieldHistory": []
      },
      "StartDate": {
        "DisplayValue": "2015-11-18",
        "FieldHistory": []
      },
      "DateOfBirth": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "JobRole": {
        "DisplayValue": "",
        "FieldHistoryForJobRole": [
          {
            "JobRole": null,
            "EffectiveDate": "2015-11-18",
            "ChangedOn": "2015-11-18",
            "ReasonForChange": "New Starter"
          }
        ]
      }
    },
    {
      "EmployeeId": {
        "DisplayValue": "LK500200",
        "FieldHistory": [
          {
            "OldValue": "LK",
            "NewValue": "LK500200",
            "ChangedOn": "2015-11-18",
            "ReasonForChange": "We choose our own employee ids"
          },
          {
            "OldValue": "PW2",
            "NewValue": "LK",
            "ChangedOn": "2015-11-18",
            "ReasonForChange": "Because we have a specific format for our employee ids"
          }
        ]
      },
      "Title": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "FirstName": {
        "DisplayValue": "Kalani",
        "FieldHistory": []
      },
      "LastName": {
        "DisplayValue": "Gayathri",
        "FieldHistory": []
      },
      "OtherName": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "KnownAs": {
        "DisplayValue": "",
        "FieldHistory": []
      },
      "EmailId": {
        "DisplayValue": "[e-mail]",
        "FieldHistory": []
      },
      "StartDate": {
        "DisplayValue": "2015-11-17",
        "FieldHistory": []
      },
      "DateOfBirth": {
        "DisplayValue": "1992-05-08",
        "FieldHistory": []
      },
      "JobRole": {
        "DisplayValue": "IT",
        "FieldHistoryForJobRole": [
          {
            "JobRole": "IT",
            "EffectiveDate": "2015-11-17",
            "ChangedOn": "2015-11-18",
            "ReasonForChange": "New Starter"
          }
        ]
      }
    }
  ]
}

我想将EmailId和EmployeeId存储为键值对，以便将来在WSO2 ESB代理服务中引用，在该服务中我需要使用EmailId引用Employe_Id。我曾想过使用一个名称为EmailId、值为EmployeeId的属性中介器，但表达式不能用作属性中介器中的名称。如何提取这些值并将其存储在ESB代理服务中以供将来参考？

Answer 1

您可以在属性中介器中使用'expression'属性来提取值（使用xpath或jsonpath）。

但是使用属性中介器在这种情况下不起作用，因为这些属性是消息的本地属性。也就是说，当您收到一条新消息时，您将获得该属性的一个单独的新副本，而不是以前设置的值。

因此，您可以尝试以下方法之一：
-使用DBReport和DBLookup中介来存储和检索值。这将涉及建立一个数据库
-使用一个自定义中介，它将在传入消息中保存值。这里有一个示例代码，它保存一个值（来自属性）并将其与新值进行比较。您可以将其修改为仅保留值，并将其设置为新属性，以便在收到新消息时使用。