WSO2 EI，遍历JSON

Question

我正在通过WSO2 EI创建简单的REST。我要发送这个json：

{
    "array": ["Hello", "this", "is", "an", "arrray", "1", 3, 4]
}

我想迭代数组中的每个元素，并在日志中显示它们。

我为它创造了这样的序列：

<?xml version="1.0" encoding="UTF-8"?>
<sequence name="for_each_test_seq_in" trace="enable" xmlns="http://ws.apache.org/ns/synapse">
    <property expression="json-eval($.array)" name="array"
    scope="default" type="STRING" xmlns:ns="http://org.apache.synapse/xsd"/>
    <log level="full">
        <property expression="get-property('array')" name="ARRAY" xmlns:ns="http://org.apache.synapse/xsd"/>
    </log>
    <iterate expression="get-property('array')" id="iterate_one" xmlns:ns="http://org.apache.synapse/xsd">
        <target sequence="anon">
            <sequence>
                <log level="full"/>
            </sequence>
        </target>
    </iterate>
    <respond/>
</sequence>

当我启动它时，我会收到以下错误消息：

[2017-09-19 16:06:40,236] [] ERROR - SynapseXPath Evaluation of the XPath expression get-property('array') resulted in an error
org.jaxen.UnresolvableException: No Such Function get-property
    at 
org.jaxen.SimpleFunctionContext.getFunction(SimpleFunctionContext.java:127)
    at org.jaxen.ContextSupport.getFunction(ContextSupport.java:242)
    at org.jaxen.Context.getFunction(Context.java:216)
    ...

我不明白为什么get-property是未知的。我知道get-property是一个XPath函数。

我只想对array元素的每个元素进行迭代，并对它们执行一些操作。

有可能吗？

Answer 1

这是实现。

WSO的rest服务。接收请求，记录消息体，处理顺序并发送回客户端。序列for_each_test_seq_in不改变消息的内容

<?xml version="1.0" encoding="UTF-8"?>
<api context="/array" name="array" xmlns="http://ws.apache.org/ns/synapse">
    <resource methods="POST">
        <inSequence>
            <log>
                <property expression="json-eval($.*)" name="==============="/>
            </log>
            <sequence key="for_each_test_seq_in"/>
            <loopback/>
        </inSequence>
        <outSequence>
            <send/>
        </outSequence>
        <faultSequence/>
    </resource>
</api>

这是序列代码

<?xml version="1.0" encoding="UTF-8"?>
<sequence name="for_each_test_seq_in" trace="disable" xmlns="http://ws.apache.org/ns/synapse">
    <property expression="json-eval($.array)" name="array" scope="default" type="STRING"/>
    <log level="full">
        <property expression="get-property('array')" name="ARRAY" xmlns:ns="http://org.apache.synapse/xsd"/>
    </log>
    <foreach expression="//array">
        <sequence>
            <log level="full"/>
        </sequence>
    </foreach>
</sequence>

下面图片上的post请求示例

​

服务器状态日志

[2017-10-16 23:55:18,375] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, =============== = [[34,234,"example",56.3,"mom"]]
[2017-10-16 23:55:18,379] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, ARRAY = [34,234,"example",56.3,"mom"], Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><jsonObject><array>34</array><array>234</array><array>example</array><array>56.3</array><array>mom</array></jsonObject></soapenv:Body></soapenv:Envelope>
[2017-10-16 23:55:18,380] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><array>34</array></soapenv:Body></soapenv:Envelope>
[2017-10-16 23:55:18,381] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><array>234</array></soapenv:Body></soapenv:Envelope>
[2017-10-16 23:55:18,381] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><array>example</array></soapenv:Body></soapenv:Envelope>
[2017-10-16 23:55:18,381] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><array>56.3</array></soapenv:Body></soapenv:Envelope>
[2017-10-16 23:55:18,382] [EI-Core]  INFO - LogMediator To: /array, MessageID: urn:uuid:648f7e51-4c71-48d7-8d09-f914ce29a867, Direction: request, Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><array>mom</array></soapenv:Body></soapenv:Envelope>

第一行由

<log><property expression="json-eval($.*)" name="==============="/></log>
 ...=============== = [[34,234,"example",56.3,"mom"]]

第二条日志行是部分代码按顺序排列的结果。

<log level="full">
    <property expression="get-property('array')" name="ARRAY"/>
</log>
  ....Direction: request, ARRAY = [34,234,"example",56.3,"mom"], Envelope: <?xml version='1.0' encoding='utf-8'?><soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"><soapenv:Body><jsonObject><array>34</array><array>234</array><array>example</array><array>56.3</array><array>mom</array></jsonObject></soapenv:Body></soapenv:Envelope>

如您所见，它有两种表示形式。其中一种是json格式：

ARRAY = [34,234,"example",56.3,"mom"]

第二种是根据https://docs.wso2.com/display/ESB500/JSON+Support中描述的规则使用xml表示法( JSON有效载荷的表示章)

<?xml version='1.0' encoding='utf-8'?>
   <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
           <soapenv:Body>
               <jsonObject>
                   <array>34</array>
                   <array>234</array>
                   <array>example</array>
                   <array>56.3</array>
                   <array>mom</array>
           </jsonObject>
    </soapenv:Body>
</soapenv:Envelope>

文档声明，如果您考虑使用xml中的json表示，就可以在json有效负载上应用xpath。使用此方法，只需应用xpath // array 来获取数组的每个部分。

因此，在xml表示中，原始数组由数组的每个元素喷出并登录到控制台中。您可以在其余的日志中看到它。

LogMediator To: /array, MessageID: urn:uuid:6...  Envelope: <soapenv:Body><array>34</array></soapenv:Body>
LogMediator To: /array, MessageID: urn:uuid:6.... Envelope: <soapenv:Body><array>234</array></soapenv:Body>
LogMediator To: /array, MessageID: urn:uuid:6...  Envelope: <soapenv:Body><array>example</array></soapenv:Body>
LogMediator To: /array, MessageID: urn:uuid:6.... Envelope: <soapenv:Body><array>56.3</array></soapenv:Body>
LogMediator To: /array, MessageID: urn:uuid:6.... Envelope: <soapenv:Body><array>mom</array></soapenv:Body>