Unexpected character error when using multiple Json inputs in Dataweave

Question

I have a Json payload and Json flowVars. I am populating the Products array in the Stores Json payload with a Products Json flowVar but I'm seeing the following error:

INFO  2017-01-15 23:06:32,559 [[test].test-httpListenerConfig.worker.01] org.mule.api.processor.LoggerMessageProcessor: **** Stores JSON Payload: {"storeId":"1234"}
INFO  2017-01-15 23:06:32,574 [[test].test-httpListenerConfig.worker.01] org.mule.api.processor.LoggerMessageProcessor: *** Products JSON flowvar{"products": [{   "product": "phone",   "price": "499.99"  }]}
ERROR 2017-01-15 23:06:34,489 [[test].test-httpListenerConfig.worker.01] org.mule.exception.DefaultMessagingExceptionStrategy: 
********************************************************************************
Message               : Exception while executing: 
{stores={storeId=1234}, products=[]}
 ^
Unexpected character 's' at index 1 (line 1, position 2), expected '"'.
Payload               : {"storeId":"1234"}
Payload Type          : java.lang.String
Element               : /getFlow/processors/3/3 @ test:testcsv.xml:22 (Transform Message)
Element XML           : <dw:transform-message metadata:id="43b88f1f-032a-442f-94f7-09fbc853390b" doc:name="Transform Message">
                        <dw:input-payload mimeType="application/json"></dw:input-payload>
                        <dw:input-variable mimeType="application/json" variableName="varTest"></dw:input-variable>
                        <dw:set-payload>%dw 1.0%input payload application/json%output application/json---{products: flowVars.varTest.products map ((product , indexOfProduct) -> {product: product.product,price: product.price})}</dw:set-payload>
                        </dw:transform-message>
--------------------------------------------------------------------------------
Root Exception stack trace:
com.mulesoft.weave.mule.exception.WeaveExecutionException: Exception while executing: 
{stores={storeId=1234}, products=[]}
 ^
Unexpected character 's' at index 1 (line 1, position 2), expected '"'.
    at com.mulesoft.weave.mule.exception.WeaveExecutionException$.apply(WeaveExecutionException.scala:12)
    at com.mulesoft.weave.mule.WeaveMessageProcessor.execute(WeaveMessageProcessor.scala:121)
    at com.mulesoft.weave.mule.WeaveMessageProcessor.process(WeaveMessageProcessor.scala:67)

The logger shows the payload and flowVar to be in json format but the error looks like it is reading it as a hashmap. Not sure what is causing the error?

Test URL:

http://localhost:8083/api/test

XML flow:

    <?xml version="1.0" encoding="UTF-8"?>

    <mule xmlns:dw="http://www.mulesoft.org/schema/mule/ee/dw" xmlns:metadata="http://www.mulesoft.org/schema/mule/metadata" xmlns:tracking="http://www.mulesoft.org/schema/mule/ee/tracking" xmlns:json="http://www.mulesoft.org/schema/mule/json" xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:mongo="http://www.mulesoft.org/schema/mule/mongo" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
        xmlns:spring="http://www.springframework.org/schema/beans" 
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd
    http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
    http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-json.xsd
    http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
    http://www.mulesoft.org/schema/mule/mongo http://www.mulesoft.org/schema/mule/mongo/current/mule-mongo.xsd
    http://www.mulesoft.org/schema/mule/ee/tracking http://www.mulesoft.org/schema/mule/ee/tracking/current/mule-tracking-ee.xsd
    http://www.mulesoft.org/schema/mule/ee/dw http://www.mulesoft.org/schema/mule/ee/dw/current/dw.xsd">
        <flow name="getFlow">
            <http:listener config-ref="testdata-httpListenerConfig" path="/test" doc:name="HTTP"/>
        <set-variable variableName="varTest" value="{ &quot;products&quot;: [{      &quot;product&quot;: &quot;phone&quot;,         &quot;price&quot;: &quot;499.99&quot;   }]}" mimeType="application/json" doc:name="Variable"/>
        <set-payload value="[{  &quot;stores&quot;: {   &quot;storeId&quot;: &quot;1234&quot;  } }]" mimeType="application/json" doc:name="Set Payload"/>
        <json:json-to-object-transformer returnClass="java.lang.Object" doc:name="JSON to Object"/>
        <foreach doc:name="For Each" collection="#[payload]">
            <json:object-to-json-transformer mimeType="application/json" doc:name="Object to JSON"/>
            <logger message="#['**** Stores JSON Payload: ' + payload]" level="INFO" doc:name="Logger"/>
            <logger message="#['*** Products JSON flowvar' + flowVars.varTest]" level="INFO" doc:name="Logger"/>
            <dw:transform-message metadata:id="43b88f1f-032a-442f-94f7-09fbc853390b" doc:name="Transform Message">
                <dw:input-payload mimeType="application/json" doc:sample="C:\getStores.json"/>
                <dw:input-variable mimeType="application/json" variableName="varTest" doc:sample="sample_data\list_json_15.json"/>
                <dw:set-payload><![CDATA[%dw 1.0
%input payload application/json
%input in1 application/json
%output application/json
---
{
    stores: {
        storeId: payload.stores.storeId
    },
    products: flowVars.varTest.products map ((product , indexOfProduct) -> {
        product: product.product,
        price: product.price
    })
}]]></dw:set-payload>
            </dw:transform-message>                
            <logger message="#[payload]" level="INFO" doc:name="Logger"/>
            </foreach>
        </flow>
    </mule>

Stores JSON Payload:

{
    "stores": {
        "storeId": "1234"
    },
    "products": []
}

Products

{
    "products": [{
        "product": "phone",
        "price": "499.99"
    }]
}

Expected Result

{
    "stores": {
        "storeId": "1234"
    },
    "products": [{
        "product": "phone",
        "price": "499.99"
    }]
}

Thanks

Can you send me the expected JSON response?? I assume the above mentioned "stores JSON Payload" and "Products json" are the input payload's. — Senthil c
Given that Mule stores your Json objects as a string at first, your payload is not currently iterable. If you place a break-point before the for-each (maybe on the "JSON to Object" transformer) and step through, you will see that your loop never gets fired. You should also see the following message in your console: org.mule.routing.ExpressionSplitter: Splitter returned no results. If this is not expected, please check your split expression. If this is the case, then convert your payload into an iterable first. — Möoz
This is because the "payload.stores" will be returned as null, so if there's no value (or at least not one that the for-each can use), then it will never enter the loop. You should change that statement to payload[0].stores to explicitly call the first element in your object. — Möoz
In order to truly help you though, you need to tell us the actual payload you're expecting: Do you want a list of all stores (ID's) and the products within that store? — Möoz

user3165854 user3165854 · Accepted Answer · 2017-01-16T09:35:42

Thanks for looking at this. I found a solution.

When I updated my foreach collection to specify json: instead of payload <foreach collection="json:" doc:name="For Each"> then I found it completed successfully and it can iterate through the loop without the need to convert it to a Java list of hashmap.

I'm still a little confused why this works because even though I converted to Java to iterate through the list I converted the payload back to JSON using Object to JSON transformer but looks like it was not truly converted in this instance and the flow still treated it as Java.

Unexpected character error when using multiple Json inputs in Dataweave

1 Answers