WSO2，XML 到 JSON，强制将单个元素视为数组 [英] WSO2, XML to JSON, force a single element to be treated as array

问题描述

在 Enterprise Integrator 6.6.0 中，我将 XML 转换为 JSON 有效负载.

In Enterprise Integrator 6.6.0 I'm converting a XML to JSON payload.

如果 XML 源只有一个元素，它显然会被视为单个对象

If the XML source has a single element it gets obviously treated as a single object

<items>
 <item></item>
</items>

变成

{
    "items": {
        "item": {}
    }
}

但如果有更多元素，则将特定对象视为数组

but if there are more element, the specific object is treated as an array

<items>
 <item></item>
 <item></item>
</items>

变成

{
    "items": {
        "item": [{}, {}]
    }
}

有没有办法对齐特定子对象的转换?在这种情况下，我试图始终返回一个 item 数组，即使只有一个元素.

Is there a way to align the conversion of a specific sub-object? In this case, I'm trying to always return an item array, even when there is only a single element.

我了解了 xml-multiple 属性，但我不明白如何使用它；是否要手动设置为源 xml 负载?

I read about the xml-multiple property but I couldn't understand how to use it; is it to be set manually to the source xml payload?

推荐答案

您可以使用 Json 转换介体[1] 来实现您的用例.这里我们需要定义 json 模式以匹配预期的数据结构.对于上述情况，您将能够使用类似于以下内容的 json 模式.

You can use the Json transform mediator[1] to achieve your use-case. Here we need to define the json schema to match the expected data structure. For the above case you will be able to use a json schema similar to the following.

 {
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "items": {
      "type": "object",
      "properties": {
        "item": {
          "type": "array",
          "items": [
            {
              "type": "object"
            }
          ]
        }
      },
      "required": [
        "item"
      ]
    }
  },
  "required": [
    "items"
  ]
}

这指定项目是一个数组.然后可以将模式添加到注册表 [2] 并在 json 转换介体中引用.Json 转换中介器需要在 xml 到 json 转换之后添加.请参阅以下示例代理服务.

This specifies that the item is an array. Then the schema can be added to the registry [2] and referred in the json transform mediator. The Json transform mediator needs to be added after the xml to json transformation. Refer to the following sample proxy service.

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="transform"
       startOnLoad="true"
       statistics="disable"
       trace="disable"
       transports="http,https">
   <target>
      <inSequence>
         <property name="messageType" scope="axis2" value="application/json"/>
         <property name="ContentType" scope="axis2" value="application/json"/>
         <jsontransform schema="conf:/schema.json"/>
         <respond/>
      </inSequence>
   </target>
   <description/>
</proxy>
           

输入 1

<items>
 <item><val1></val1></item>
 <item><val1></val1></item>
</items>

输出 1

{
    "items": {
        "item": [
            {
                "val1": null
            },
            {
                "val1": null
            }
        ]
    }
}
        

输入 2

<items>
 <item><val1></val1></item>
</items>

输出 2

{
    "items": {
        "item": [
            {
                "val1": null
            }
        ]
    }
}

[1]-https://docs.wso2.com/display/EI660/JSON+Transform+Mediator

[1]-https://docs.wso2.com/display/EI660/JSON+Transform+Mediator

[2]-https://docs.wso2.com/display/EI660/Managing+the+Registry+

[2]-https://docs.wso2.com/display/EI660/Managing+the+Registry+

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