Dbms_xmlschema.generateschema - JAXB

Question

dbms_xmlschema.generateschema - JAXB
We want to use our Oracle produced xsd to build JAVA content trees for unmarshalling and marshalling USING JAXB. The Oracle generated xsd does NOT nest complex sequence elements properly for JAXB. Any input is appreciated.
Below is an example from the sun tutorial for using JAXB. Notice the ITEMS/ITEM structure. Below that is our example types, PL/SQL to generate xsd and the results.
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:element name="purchaseOrder" type="PurchaseOrderType"/>
<xsd:element name="comment" type="xsd:string"/>
<xsd:complexType name="PurchaseOrderType">
<xsd:sequence>
<xsd:element name="shipTo" type="USAddress"/>
<xsd:element name="billTo" type="USAddress"/>
<xsd:element ref="comment" minOccurs="0"/>
<xsd:element name="items" type="Items"/>
</xsd:sequence>
<xsd:attribute name="orderDate" type="xsd:date"/>
</xsd:complexType>
<xsd:complexType name="USAddress">
<xsd:sequence>
<xsd:element name="name" type="xsd:string"/>
<xsd:element name="street" type="xsd:string"/>
<xsd:element name="city" type="xsd:string"/>
<xsd:element name="state" type="xsd:string"/>
<xsd:element name="zip" type="xsd:decimal"/>
</xsd:sequence>
<xsd:attribute name="country" type="xsd:NMTOKEN" fixed="US"/>
</xsd:complexType>
<xsd:complexType name="Items">
<xsd:sequence>
<xsd:element name="item" minOccurs="1" maxOccurs="unbounded">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="productName" type="xsd:string"/>
<xsd:element name="quantity">
<xsd:simpleType>
<xsd:restriction base="xsd:positiveInteger">
<xsd:maxExclusive value="100"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
<xsd:element name="USPrice" type="xsd:decimal"/>
<xsd:element ref="comment" minOccurs="0"/>
<xsd:element name="shipDate" type="xsd:date" minOccurs="0"/>
</xsd:sequence>
<xsd:attribute name="partNum" type="SKU" use="required"/>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
</xsd:complexType>
<!-- Stock Keeping Unit, a code for identifying products -->
<xsd:simpleType name="SKU">
<xsd:restriction base="xsd:string">
<xsd:pattern value="\d{3}-[A-Z]{2}"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:schema>
CREATE OR REPLACE TYPE sjs.Item AS OBJECT
( "productName"                    VARCHAR2(100),
"quantity"               INTEGER
CREATE OR REPLACE TYPE sjs.Items AS TABLE OF sjs.Item
CREATE OR REPLACE TYPE sjs.purchaseOrder AS OBJECT
("comment"               VARCHAR2(100),
"Items"               Items
DECLARE
RECURSE BOOLEAN := TRUE;
ANNOTATE BOOLEAN := FALSE;
EMBEDCOLL BOOLEAN := FALSE;
Schemaurl VARCHAR2(10) := 'WWW';
XSD_TYPE XMLTYPE;
XSD_CLOB CLOB;
XML_CLOB CLOB;
XML_TYPE XMLsequenceTYPE;
valid_flag INTEGER;
p_out     CLOB;
message VARCHAR2(4000);
BEGIN
EXECUTE IMMEDIATE 'CREATE OR REPLACE DIRECTORY XML_DIR AS ''C:\XMLAPI_PRODUCE''';
XSD_TYPE := dbms_xmlschema.generateschema('SJS','ITEMS','purchaseOrder',RECURSE,ANNOTATE,EMBEDCOLL);
XSD_CLOB := XSD_TYPE.getclobval;
sjs.file_util.write_clob(XSD_CLOB,'po.xsd','C:\XMLAPI_PRODUCE');
DBMS_LOB.CREATETEMPORARY(xml_CLOB,TRUE,dbms_lob.CALL);
DBMS_LOB.OPEN(xml_CLOB, DBMS_LOB.LOB_READWRITE);
DBMS_LOB.CREATETEMPORARY(xsd_CLOB,TRUE,dbms_lob.CALL);
DBMS_LOB.OPEN(xsd_CLOB, DBMS_LOB.LOB_READWRITE);
DBMS_LOB.CLOSE(xml_CLOB);
DBMS_LOB.FREETEMPORARY(xml_CLOB);
DBMS_LOB.CLOSE(xsd_CLOB);
DBMS_LOB.FREETEMPORARY(xsd_CLOB);
END;
<?xml version="1.0"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xdb="http://xmlns.oracle.com/xdb" xsi:schemaLocation="http://xmlns.oracle.com/xdb http://xmlns.oracle.com/xdb/XDBSchema.xsd">
<xsd:element name="purchaseOrder" type="ITEMSType"/>
<xsd:complexType name="ITEMSType">
<xsd:sequence>
<xsd:element name="ITEMS_ITEM" type="ITEMType" maxOccurs="unbounded" minOccurs="0"/>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="ITEMType">
<xsd:sequence>
<xsd:element name="productName">
<xsd:simpleType>
<xsd:restriction base="xsd:string">
<xsd:maxLength value="100"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
<xsd:element name="quantity" type="xsd:integer"/>
</xsd:sequence>
</xsd:complexType>
</xsd:schema>

Answer 1

DB Structure
Parent Table - Incident --> Child Table - IncidentCharges --> Child Table of IncidentCharges --> IncidentChargeWeapons
Container
Oracle Containers for JAVA(OC4J)
We have a schema (Incident.xsd) which comprises of our entire database structure. We unmarshalled the schema using JAXB to Java classes and interfaces .
It created 2 .java classes and 2 .java interfaces for each high level tag . for eg for our Incident tag it created a Incident interface and a IncidentType Interface
and also it created 2 classes IncidentImpl and IncidentTypeImpl . The IncidentTypeImpl has all the get and set properties we require eg. getIncidentType,
setIncidentType,getIncidentNumber,setIncidentNumber,getOccuranceDate,setOccuranceDate etc.
Our objective is to create a JSP page which has form fields to enter data which use these JAXB generated classes get and set properties. In other words
we want to bind the JSP form fields to these JAXB generated classes. And once these JAXB objects are populated we want to marshal it and create a XML file with the data from those JAXB . Our database would then consume the generated XML. We tried creating a simple incident form with just 3 fields IncidentType,Occurance date and Incident Number and tried to bind these fields with the properties from IncidentTypeImpl classes using the <jsp:usebean> tag . When we deployed it to our container and tried to load the Incident.jsp page , it would not load up . Only when we cleared all the bindings it loaded up .
Then we tried another workaround (just to get it working. Not a preferred approach) . We created another simple JAVA bean(not JAXB generated beans) which has set and get properties for the form fields and bound the form fields to it.
On submitting the JSP page we called a servlet which takes data from our created bean and transfers it to the JAXB generated IncidentTypeImpl bean. When we deployed this the jsp page loads up and also our bean is filled with data . But the servlet bombs with this error below.
500 Internal Server Error
java.lang.NoClassDefFoundError: javax/xml/bind/JAXBContext
     at Servlets.IncidentServlet.doPost(Unknown Source)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:760)
     at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.invoke(ServletRequestDispatcher.java:765)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.ServletRequestDispatcher.forwardInternal(ServletRequestDispatcher.java:317)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.processRequest(HttpRequestHandler.java:790)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:270)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].server.http.HttpRequestHandler.run(HttpRequestHandler.java:112)
     at com.evermind[Oracle Application Server Containers for J2EE 10g (9.0.4.0.0)].util.ReleasableResourcePooledExecutor$MyWorker.run(ReleasableResourcePooledExecutor.java:186)
     at java.lang.Thread.run(Thread.java:534)
We have 2 questions .
1. Can a JSP page be bound directly to this JAXB generated bean in pretty much the same way as we bind it to our own bean ? (We would like to do this so that we dont have to create duplicate classes which mirror the JAXB generated classes.)
2. Is there something special we have to do to deploy this application to recognize the JAXB classes. Do we have to deploy some jar file for it to recognize those classes ?