Physical Data Service from a Java Function

This page last changed on Mar 24, 2008.

Physical Data Service from a Java Function - Example Code

This topic provides examples showing the use of imported Java functions in an XQuery and the processing of complex types.

Using a Function Returning an Array of Java Primitives
Processing complex types represented via XMLBeans

Using a Function Returning an Array of Java Primitives

As an example, the Java function getRunningTotal can be defined as follows:

public static float[] getRunningTotal(float[] list) {
   if (null == list || 1 >= list.length)
      return list;
   for (int i = 1; i < list.length; i++) {
      list[i] = list[i-1] + list[i];
   }
   return list;
}

The corresponding XQuery for executing the above function is as follows:

Declare namespace f1="ld:javaFunc/float"
Let $y := (2.0, 4.0, 6.0, 8.0, 10.0)
Let $x := f1:getRunningTotal($y)
Return $x

The results of the query is as follows:

2.0, 6.0, 12.0, 20.0, 30.0

Processing complex types represented via XMLBeans

Consider a schema called Customer (customer.xsd), as shown in the following:

<?xml version="1.0" encoding="UTF-8" ?>
   <xs:schema targetNamespace="ld:xml/cust:/BEA_BB10000" xmlns:xs="http://www.w3.org/2001/XMLSchema">
   <xs:element name="CUSTOMER">
      <xs:complexType>
         <xs:sequence>
            <xs:element name="FIRST_NAME" type="xs:string" minOccurs="1"/>
            <xs:element name="LAST_NAME" type="xs:string" minOccurs="1"/>
         </xs:sequence>
      </xs:complexType>
   </xs:element>
</xs:schema>

You could compile the schema using XMLBeans to generate a Java class corresponding to the types in the schema.

xml.cust.beaBB10000.CUSTOMERDocument.CUSTOMER

For more information, see http://xmlbeans.apache.org.

Following this, you can use the CUSTOMER element as shown in the following:

public static xml.cust.beaBB10000.CUSTOMERDocument.CUSTOMER[]
      getCustomerListGivenCustomerList(xml.cust.beaBB10000.CUSTOMERDocument.CUSTOMER[] ipListOfCust)
      throws XmlException {
   xml.cust.beaBB10000.CUSTOMERDocument.CUSTOMER [] mylocalver = pListOfCust;
   return mylocalver;
}

The resulting metadata information produced by the New Physical Data Service wizard will be:

(::pragma function <f:function xmlns:f="urn:annotations.ld.bea.com" kind="datasource" access="public">
<params>
<param nativeType="[Lxml.cust.beaBB10000.CUSTOMERDocument$CUSTOMER;"/>
</params>
</f:function>::)

declare function f1:getCustomerListGivenCustomerList($x1 as element(t1:CUSTOMER)*) as element(t1:CUSTOMER)* external;

The corresponding XQuery for executing the above function is:

declare namespace f1 = "ld:javaFunc/CUSTOMER";
let $z := (
validate(<n:CUSTOMER xmlns:n="ld:xml/cust:/BEA_BB10000"><FIRST_NAME>John2</FIRST_NAME><LAST_NAME>Smith2</LAST_NAME>
</n:CUSTOMER>),

validate(<n:CUSTOMER xmlns:n="ld:xml/cust:/BEA_BB10000"><FIRST_NAME>John2</FIRST_NAME><LAST_NAME>Smith2</LAST_NAME>
</n:CUSTOMER>),

validate(<n:CUSTOMER xmlns:n="ld:xml/cust:/BEA_BB10000"><FIRST_NAME>John2</FIRST_NAME><LAST_NAME>Smith2</LAST_NAME>
</n:CUSTOMER>),

validate(<n:CUSTOMER xmlns:n="ld:xml/cust:/BEA_BB10000"><FIRST_NAME>John2</FIRST_NAME><LAST_NAME>Smith2</LAST_NAME>
</n:CUSTOMER>))

for $zz in $z
return