使用`jsonPath`筛选出具有空数组的元素的表达式 [英] Expression to filter out elements with empty arrays using `jsonPath`

问题描述

我有以下格式的JSON有效负载:

I have a JSON payload of the form:

[
  {"id": 1, "list": [1], "name":"one"}, 
  {"id": 2, "list": [1,2], "name":"two"},
  {"id": 3, "list": [], "name":"three"}
]

我想从数组中滤除元素，其中包含一个空的"list"属性.换句话说，我想用id=3放弃该元素，而仅在上面的示例中处理第一个和第二个元素.

And I want to filter out the element from the array the contains an empty "list" property. In other words, I want to discard the element with id=3 and process only the first and second element in my example above.

当前，我的过滤器如下所示:

Currently, my filter looks like this:

<!-- ne == not equals -->
<int:filter id="filter" 
            input-channel="in" 
            output-channel="out" 
            expression="#jsonPath(payload, '$[*].list') ne '[]'"
            discard-channel="consoleOutputChannel" />

但这不起作用，如何向我的expression指示要排除具有空list属性的元素?

But this is not working, how should I indicate to my expression that I want to exclude elements with empty list properties?

推荐答案

将表达式更改为:

$.[?(@.list.length()> 0)]

• [?(<expression>)]:过滤器表达式
• @:正在处理的当前节点 通过过滤谓词
• list.length():list数组的长度
• [?(<expression>)] : filter expression
• @ : The current node being processed by a filter predicate
• list.length() : the length of list array

更多详细信息，请参见 JsonPath

More detail at JsonPath

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