Jasperserver report execution service with collection parameter

I have some trouble generating jasper report when i try to pass more than on value to a collection type parameter in my request body. In my rapport my parameter is decribed like this

<parameter name="skillList" class="java.util.Collection" nestedType="java.lang.String">
 <parameterDescription><![CDATA[list of skill]]></parameterDescription>
</parameter>

In jaspersoft studio when i tried to visualize my report and add more value it work well and my report is generated

But when i try to use the execution service of the server using HTTP POST with a request body like this one :

<reportExecutionRequest>
    <reportUnitUri>MyReportURI</reportUnitUri>
    <async>false</async>
    <outputFormat>pdf</outputFormat>
    <parameters>
        <reportParameter name="title">
            <value>--- titre test ---</value>
        </reportParameter>
        <reportParameter name="header">
            <value>@@@ header test @@@</value>
        </reportParameter>
        <reportParameter name="name">
            <value>LE TUTOUR</value>
        </reportParameter>
        <reportParameter name="surname">
            <value>Erwan</value>
        </reportParameter>
        <reportParameter name="skillList">
                <value>java</value>
                <value>maven</value>
        </reportParameter>
    </parameters>
</reportExecutionRequest>

If I have only one value in the skillList parameter my rapport is well generated, but when I add another one I have a HTTP 400 bad request.

In the documentation of the service there is many exemple with more than one value so i don't understand why my repport is not generated.

If someone have a solution or have encountered the same issue and solved it i woul not say no to some help.

edit In a new attempt I changed my parameter, it's now a subdataset

    <subDataset name="listSkill" uuid="8027f62e-3b29-4faf-b11a-185b4db46d6f">
            <field name="skill" class="java.lang.String">
                <fieldDescription><![CDATA[_THIS]]></fieldDescription>
            </field>

</subDataset>

and the way to use it

<componentElement>
                <reportElement x="0" y="200" width="100" height="30" uuid="26b52f0f-e1e0-451e-9183-2df0f1f1ce65"/>
                <jr:list xmlns:jr="http://jasperreports.sourceforge.net/jasperreports/components" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports/components http://jasperreports.sourceforge.net/xsd/components.xsd">
                    <datasetRun subDataset="listSkill" uuid="593d4d96-cbaf-46ba-94ef-97344e0cb4f2">
                        <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($P{skills}) ]]></dataSourceExpression>
                    </datasetRun>
                    <jr:listContents height="30" width="100">
                        <textField>
                            <reportElement x="0" y="0" width="100" height="30" uuid="061f84d9-205a-4f49-a711-1f657b1fa5fd"/>
                            <textFieldExpression><![CDATA[$F{skill}]]></textFieldExpression>
                        </textField>
                    </jr:listContents>
                </jr:list>
            </componentElement>

still work in jaspersoft studio when I generate my report, but not when in try to execute it, using the REST API of the server.

Solved this:

Now I only pass 1 parameter to my rapport, a json string with all my parameters as fields.

I use a data adapter that match that string and replaced all the $P{xxxx} by $F{xxxx}.

Then I use the JSON_INPUT_STREAM parameter of the report to cast that string to byte array input stream.

In this json string, my lists object are described like this

"LIST_SKILL": [
    ["skill one", "value 1"],
    ["skill two", "value 2"],
    ["skill three", "value 3"]
]

Then on my list object, in the dataSet properties::JRDatasource expression

((net.sf.jasperreports.engine.data.JsonDataSource)$P{REPORT_DATA_SOURCE}).subDataSource("LIST_SKILL")

After that, my report is correctly generated in jaspersoft studio / server and with rest service call.