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. 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. Jeff /** * [EMAIL PROTECTED] (818) 354-5472 * http://robotics.jpl.nasa.gov/people/jnorris/ */ > -----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/ > > */ > > > > ----------------------------------------------------------- > > If you wish to unsubscribe from this mailing, send mail to > > [EMAIL PROTECTED] with a subject of: > > unsubscribe castor-dev > > ----------------------------------------------------------- > If you wish to unsubscribe from this mailing, send mail to > [EMAIL PROTECTED] with a subject of: > unsubscribe castor-dev > ----------------------------------------------------------- If you wish to unsubscribe from this mailing, send mail to [EMAIL PROTECTED] with a subject of: unsubscribe castor-dev
