用于检查 Apache Camel XML 中字符串的 JSONPath 表达式 [英] JSONPath expression for checking string in Apache Camel XML

问题描述

假设我有一个简单的 json 文件，如下所示

Let's say I have a simple json file such as the following

{
    "log": {
        "host": "blah",
        "severity": "INFO",
        "system": "1"
    }
}

我使用的是 Apache Camel，它是 Spring XML 来处理和路由 json 文件.我的路由代码如下所示:

I'm using Apache Camel, and it's Spring XML to process and route the json file. My routing code looks something like this:

<route>
    <from uri="file:/TESTFOLDER/input"/>
    <choice>
      <when>
        <jsonpath>$.log?(@.severity == 'WARNING')</jsonpath>
        <to uri="smtp://(smtpinfo...not important)"/>
      </when>
      <otherwise>
        <to uri="file:/TESTFOLDER/output"/>
      </otherwise>
    </choice>
</route>

我真正感到困惑的部分是 JSONPath 表达式.我上面的表达式甚至在语法上都不正确，因为在您不尝试对元素列表进行排序的情况下，很难找到示例.我的目标是仅在日志的严重性为警告"时发送电子邮件，但我无法想出表达式.

The part that I'm really confused about is the JSONPath expression. The expression I have above isn't even syntactically correct, because its hard to find examples for the case where you aren't trying to sort through a list of elements. My goal is to only send an email if the severity of the log is 'WARNING' but I can't come up with the expression.

推荐答案

这对我使用 Camel 2.13.1 有用(我检查了 INFO 因为您的 JSON 示例具有此 severity；您可以根据需要进行更改):

This worked for me using Camel 2.13.1 (I checked for INFO as your JSON example has this severity; you may change this according to your needs):

<jsonpath>$..log[?(@.severity == 'INFO')]</jsonpath>

注意 .. 和 [].但是，在搜索路径的开头使用单点 . 失败:

Note the .. and the []. However, using a single dot . at the beginning of the search path failed:

<jsonpath>$.log[?(@.severity == 'INFO')]</jsonpath>

错误信息说:

java.lang.IllegalArgumentException: Invalid container object

这可能是一个错误.

根据 JSON 路径 doc，.. 代表递归下降".这可能不符合您的要求.但是，由于单点 . 不起作用，这是我想到的唯一可能的解决方法.否则，您可能会收到错误通知单.

According to the JSON Path doc, .. stands for "recursive descent". This may not meet your requirements. However, as a single dot . didn't work, this was the only possible work around I figured out. Otherwise, you may rise a bug ticket.

这篇关于用于检查 Apache Camel XML 中字符串的 JSONPath 表达式的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！