Java EE (Java Enterprise Edition) General Discussion

Trying to follow a contract-first approach for creating web services. I got stuck when created the following WSDL (I didn't finish as I ran into a problem with the types/schema tags):

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

<wsdl:definitions name="MyWebService"
    targetNamespace="http://web.foobar.com"
    xmlns:tns="http://web.foobar.com"
    xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
    xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema">

    <!-- T Y P E S -->
    <wsdl:types>
        <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            targetNamespace="http://transactions.foobar.com"
            xmlns="http://transactions.foobar.com"
            elementFormDefault="qualified">

            <xsd:element name="Transactions">
                <xsd:complexType>
                    <xsd:sequence maxOccurs="10">
                        <xsd:element name="Transaction" type="xsd:string"/>
                    </xsd:sequence>
                </xsd:complexType>
            </xsd:element>
           
        </xsd:schema>
       
        <xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            targetNamespace="http://web.foobar.com"
            xmlns="http://web.foobar.com"
            xmlns:txn="http://transactions.foobar.com"
            elementFormDefault="qualified">
           
            <xsd:element name="processTransactionsInput" type="processTransactionsInputType"/>

            <xsd:complexType name="processTransactionsInputType">
                <xsd:sequence>
                    <!-- Does not like referencing from the previous schema tag -->
                    <xsd:element ref="txn:Transactions"/>

                    <!-- This one is okay cuz it is easy -->
                    <xsd:element name="SendDate" type="xsd:date"/>
                </xsd:sequence>
            </xsd:complexType>
           
        </xsd:schema>
    </wsdl:types>
</wsdl:definitions>

I get the following warning when running WsImport using JAX-WS RI 2.1.1:

[WARNING] src-resolve.4.2: Error resolving component 'txn:Transactions'. It was detected that 'txn:Transactions' is in namespace 'http://transactions.foobar.com', but components from this namespace are not referenceable from schema document 'file:/C:/foobar/MyWebService.wsdl#types?schema2'. If this is the incorrect namespace, perhaps the prefix of 'txn:Transactions' needs to be changed. If this is the correct namespace, then an appropriate 'import' tag should be added to 'file:/C:/foobar/MyWebService.wsdl#types?schema2'.

I have one XML object "Transactions" is in different namespace as my web service.

Transactions has the following namespace: http://transactions.foobar.com
My web service has the following namespace: http://web.foobar.com

The actual message my web service needs is a "Transactions" object AND a timestamp. These two together form the input message to my web service.

What's going on here?