Jeff Norris wrote:
>
> I have determined the source of the error I encountered with the xsi:type=""
> attribute. The problem is that I have installed castor as a java extension (the
> jar file is symlinked in the jdk/jre/lib/ext/ directory), and I would bet money
> that you (Keith) have it on your classpath. Java extensions use the
> ExtClassLoader by default, which unfortunately does not have access to the
> application classpath. This is not a security issue-- it is in my opinion an
> unfortunate by-product of some design decisions made by Sun.
>
> http://www.javageeks.com/Papers/ClassForName/ClassForName.pdf
>
> What this means for Castor users is that Castor, if installed as a java
> extension, will NOT be able to locate any user-defined classes that are not
> themselves installed as extensions through the simple, one argument
> Class.forName() call. Fortunately, there are some workarounds, described in
> detail in the document referenced above. Each workaround has some minor
> consequences that will have to be considered by the Castor development team.
> Most notably, one of the workarounds uses features that are only in Java 1.2 and
> above. Does Castor even support the 1.1 JVM at all? If not, then I think that
> the workarounds have no serious consequences and should become part of Castor.
Yes, as Arnaud mentioned in his e-mail, Castor XML does support JDK 1.1
(Castor JDO does not have this requirement).
The main reason is that we have some "influential" users that require
JDK 1.1 support. When I say influential users, I mean users that enable
me to continue working on Castor. :-)
>
> Keith- I plan to try making the modifications described in the document above on
> my local copy of Castor and will let you know how it goes. I'd be very
> interested to hear your thoughts on this, though, particularly whether *you* are
> comfortable with the consequences of the workaround.
I'll need to read the document, but I need to grab some food first...
Also please let me know if my fix for "xsi:type" with regards to Schema
name vs. Java class name works for you.
Thanks,
--Keith
> > -----Original Message-----
> > From: Keith Visco [mailto:[EMAIL PROTECTED]]
> > Sent: Monday, January 14, 2002 7:33 PM
> > To: [EMAIL PROTECTED]
> > Subject: Re: [castor-dev] BUG: Castor fails to find class for
> > xsi:type="java:MyClass" - Example included.
> >
> >
> >
> > Hi Jeff,
> >
> > I just ran your test case, and it appears fine for me. The output I get
> > is:
> >
> > BugTest
> > Beginning test #1
> > Test 1 suceeded.
> > Beginning test #2
> > Test 2 suceeded.
> >
> >
> > I am using the CVS version. I don't think any changes have gone into the
> > CVS that would affect this issue, but you might want to try it.
> >
> > If not, it sounds to me like it could be a CLASSPATH issue. Are you
> > running inside of a Servlet or App server engine?
> >
> > I will still look into the second issue: xsi:type="java:ChildType"
> > instead of xsi:type="childType"
> >
> > Thanks,
> >
> > --Keith
> >
> >
> > Jeff Norris wrote:
> > >
> > > First, I continue to be amazed by Castor. It is truly a first-rate
> > product and
> > > has saved my development staff countless hours. I have taken the time to
> > > carefully write a detailed bug report and include a test program because I
> > > appreciate Castor so much and want to see it continue to improve. On to the
> > > bug...
> > >
> > > Castor 0.9.3.9 is not able to locate the class for a derived type
> > that has been
> > > specified in an XML file with xsi:type="java:fully.qualified.ClassName" and
> > > throws a ClassNotFoundException. This occurs even when the file being
> > > unmarshalled was originally written by Castor. Note that I *AM*
> > including the
> > > "java:" prefix and am specifing the fully qualified class name of
> > the desired
> > > derived type.
> > >
> > > I have constructed a simple schema, xml file, and test program which will
> > > illustrate the problem. Note that I am using the "type" method in
> > the source
> > > generator - if you use the "element" method then you will have to slightly
> > > modify BugTest.java.
> > >
> > > ***** THE SCHEMA (bugtest.xsd):
> > >
> > > <?xml version="1.0" encoding="UTF-8"?>
> > > <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema";>
> > > <xs:element name="root">
> > > <xs:complexType>
> > > <xs:sequence>
> > > <xs:element name="foo" type="parentType"/>
> > > </xs:sequence>
> > > </xs:complexType>
> > > </xs:element>
> > > <xs:complexType name="parentType">
> > > <xs:sequence>
> > > <xs:element name="a" type="xs:int"/>
> > > </xs:sequence>
> > > </xs:complexType>
> > > <xs:complexType name="childType">
> > > <xs:complexContent>
> > > <xs:extension base="parentType">
> > > <xs:sequence>
> > > <xs:element name="b" type="xs:int"/>
> > > </xs:sequence>
> > > </xs:extension>
> > > </xs:complexContent>
> > > </xs:complexType>
> > > </xs:schema>
> > >
> > > ***** THE XML FILE (bugtest.xml):
> > >
> > > <?xml version="1.0" encoding="UTF-8"?>
> > > <root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
> > > xsi:noNamespaceSchemaLocation="bugtest.xsd">
> > > <foo xsi:type="java:ChildType">
> > > <a>0</a>
> > > <b>1</b>
> > > </foo>
> > > </root>
> > >
> > > ***** THE TEST PROGRAM (BugTest.java):
> > >
> > > import java.io.*;
> > >
> > > public class BugTest
> > > {
> > > public static void main (String[] args)
> > > {
> > > try {
> > > // TEST 1 - attempt to unmarshal a hand-written xml file that
> > > // contains a derived element.
> > > System.out.println("Beginning test #1");
> > > FileReader reader = new FileReader("bugtest.xml");
> > > Root root = Root.unmarshalRoot(reader);
> > > System.out.println("Test 1 suceeded.");
> > > } catch (Exception e) {
> > > System.out.println("Test 1 failed.");
> > > e.printStackTrace();
> > > } // end of try-catch
> > >
> > > try {
> > > // TEST 2 - attempt to marshal and unmarshal an xml file with
> > > // a derived element
> > > System.out.println("Beginning test #2");
> > > Root root = new Root();
> > > root.setFoo(new ChildType());
> > > ((ChildType)root.getFoo()).setA(1);
> > > ((ChildType)root.getFoo()).setB(2);
> > > FileWriter writer = new FileWriter("bugtest2.xml");
> > > root.marshal(writer);
> > > FileReader reader = new FileReader("bugtest2.xml");
> > > root = Root.unmarshalRoot(reader);
> > > System.out.println("Test 2 suceeded.");
> > > } catch (Exception e) {
> > > System.out.println("Test 2 failed.");
> > > e.printStackTrace();
> > > } // end of try-catch
> > >
> > > } // end of main ()
> > > }
> > >
> > > ***** OUTPUT FROM THE TEST PROGRAM:
> > >
> > > > java BugTest
> > > Beginning test #1
> > > Test 1 failed.
> > > org.xml.sax.SAXException: unable to instantiate ChildType;
> > > java.lang.ClassNotFoundException: ChildType
> > > at
> > >
> > org.exolab.castor.xml.UnmarshalHandler.startElement(UnmarshalHandler.java:957)
> > > at
> > org.apache.xerces.parsers.SAXParser.startElement(SAXParser.java:1335)
> > > at
> > >
> > org.apache.xerces.validators.common.XMLValidator.callStartElement(XMLV
> > alidator.j
> > > ava:823)
> > > at
> > >
> > org.apache.xerces.framework.XMLDocumentScanner.scanElement(XMLDocument
> > Scanner.ja
> > > va:1852)
> > > at
> > >
> > org.apache.xerces.framework.XMLDocumentScanner$ContentDispatcher.dispa
> > tch(XMLDoc
> > > umentScanner.java:1233)
> > > at
> > >
> > org.apache.xerces.framework.XMLDocumentScanner.parseSome(XMLDocumentSc
> > anner.java
> > > :380)
> > > at org.apache.xerces.framework.XMLParser.parse(XMLParser.java:900)
> > > at
> > org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:338)
> > > at
> > org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:270)
> > > at
> > org.exolab.castor.xml.Unmarshaller.unmarshal(Unmarshaller.java:391)
> > > at Root.unmarshalRoot(Root.java:173)
> > > at BugTest.main(BugTest.java:10)
> > > Beginning test #2
> > > Test 2 failed.
> > > org.xml.sax.SAXException: unable to instantiate ChildType;
> > > java.lang.ClassNotFoundException: ChildType
> > > at
> > >
> > org.exolab.castor.xml.UnmarshalHandler.startElement(UnmarshalHandler.java:957)
> > > at
> > org.apache.xerces.parsers.SAXParser.startElement(SAXParser.java:1335)
> > > ... etc, same as above
> > >
> > > ***** XML FILE WRITTEN DURING TEST #2:
> > >
> > > For reference, here is bugtest2.xml, which is the xml file written by Castor
> > > during test #2:
> > >
> > > <?xml version="1.0"?>
> > > <root><foo xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
> > > xsi:type="java:ChildType"><a>1</a><b>2</b></foo></root>
> > >
> > > Note that the xsi:type tag is exactly the same as it was in the hand-written
> > > bugtest.xml above.
> > >
> > > As a side note, It would be fantastic if Castor were able to handle derived
> > > types without the "java:" prefix in the xsi:type attribute. Castor-written
> > > documents with derived types can't be loaded into any commercial
> > xml editor (IE,
> > > XMLSpy) since they don't recongnize the "java:" prefix.
> > >
> > > Jeff
> > >
> > > /**
> > > * [EMAIL PROTECTED]
> > > * http://robotics.jpl.nasa.gov/people/jnorris/
> > > */
> > >
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