thread-safety of XPath classes

[Jesus M. Salvo Jr.]

Would just like to know if there any thread-safety issues with Xalan's 
XPath classes.

What I am doing are the following:
Declare the following as intance variables in a servlet:
 protected org.apache.xpath.compiler.Compiler  xPathcompiler;
 protected SAXSourceLocator  locator;
 protected XPathParser       xParser;
... initialise them:
   this.xPathcompiler = new org.apache.xpath.compiler.Compiler();
   this.locator = new SAXSourceLocator();
   this.xParser = new XPathParser( new DefaultErrorHandler( System.out 
), locator );

The rest are local to a method, such as intances of XPath and instances 
of XObject.