Problem:
NB5.5 EntPack xmltools provides capability to edit schema using its Schema view (a tree or column representation), and it internally calls JDK Schema validator, at certain point when the user is editing xml schema. For the attached schema, the issue is that IDE appears hanging while invoking JDK JAXP schema validator.

Issue:
Schema validator that comes bundled with JDK 1.5.0_09 or JDK1.6beta2 is slow with attached schema (See source code section for the schema)

Steps to reproduce:

1. download attachment, and unzip to "C:\tmp"
2. cd c:\tmp\SchemaValidate
3. java -Xmx256m -classpath .\dist\SchemaValidate.jar;$classpath schemavaliate.Main c:\tmp\SchemaValidate\src\schemavalidate\CREMAS04.xsd

This would take about 20min to validate.

There is no error message, however I have taken the thread dump, below is the relevant information:

The code seems to be hanging at CMStateSet.java:226

==========================================================
        at com.sun.org.apache.xerces.internal.impl.dtd.models.CMStateSet.union(C
MStateSet.java:226)
        at com.sun.org.apache.xerces.internal.impl.xs.models.XSDFACM.buildDFA(XS
DFACM.java:562)
        at com.sun.org.apache.xerces.internal.impl.xs.models.XSDFACM.<init>(XSDF
ACM.java:182)
        at com.sun.org.apache.xerces.internal.impl.xs.models.CMBuilder.createDFA
CM(CMBuilder.java:132)
        at com.sun.org.apache.xerces.internal.impl.xs.models.CMBuilder.getConten
tModel(CMBuilder.java:92)
        at com.sun.org.apache.xerces.internal.impl.xs.XSComplexTypeDecl.getConte
ntModel(XSComplexTypeDecl.java:153)
        - locked <0x05fe2ef0> (a com.sun.org.apache.xerces.internal.impl.xs.XSCo
mplexTypeDecl)
        at com.sun.org.apache.xerces.internal.impl.xs.XSConstraints.fullSchemaCh
ecking(XSConstraints.java:421)
        at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGramma
r(XMLSchemaLoader.java:526)
        at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaLoader.loadGramma
r(XMLSchemaLoader.java:485)
        at com.sun.org.apache.xerces.internal.jaxp.validation.XMLSchemaFactory.n
ewSchema(XMLSchemaFactory.java:206)
        at javax.xml.validation.SchemaFactory.newSchema(SchemaFactory.java:585)
=======================================================
Attaching schema from http://www.netbeans.org/issues/show_bug.cgi?id=87152 for testing purposes
Also, found that validating following following (each) schema would take 3-4 sec.
I would expect each validation should be <<1 sec (in millis rather than seconds).

The issue here is if in our tool (NB5.5 EntPack Schema tool) user (after opening file messages.xsd in IDE), tries to expand messages.xsd|Groups|ALLMESSAGES.CONTENT|choice|ACK element, it will try to open files "ACK.xsd" "segments.xsd|" fields.xsd" "datatypes.xsd". While opening this file it will also try to validate these schema files. This will cause the IDE to appear slow to user doing certain basic operation in schema tools. You can see we are talking about some 10-15 sec, on top on other UI time spend by the schema tool. This is unacceptable to schema tools user.

To get this schema download attached hl7_v2.3.zip file into c:\tmp\hld.

C:\Documents and Settings\Owner\SchemaValidate>java -Xmx256m -classpath dist\Sch
emaValidate.jar;%classpath% schemavalidate.Main "C:\tmp\hld\messages.xsd"

C:\Documents and Settings\Owner\SchemaValidate>java -Xmx256m -classpath dist\Sch
emaValidate.jar;%classpath% schemavalidate.Main "C:\tmp\hld\ACK.xsd"

C:\Documents and Settings\Owner\SchemaValidate>java -Xmx256m -classpath dist\Sch
emaValidate.jar;%classpath% schemavalidate.Main "C:\tmp\hld\segments.xsd"

C:\Documents and Settings\Owner\SchemaValidate>java -Xmx256m -classpath dist\Sch
emaValidate.jar;%classpath% schemavalidate.Main "C:\tmp\hld\fields.xsd"

C:\Documents and Settings\Owner\SchemaValidate>java -Xmx256m -classpath dist\Sch
emaValidate.jar;%classpath% schemavalidate.Main "C:\tmp\hld\datatypes.xsd"