FULL PRODUCT VERSION :
java version "1.6.0_13"
Java(TM) SE Runtime Environment (build 1.6.0_13-b03)
Java HotSpot(TM) Client VM (build 11.3-b02, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Windows XP SP2

A DESCRIPTION OF THE PROBLEM :
org.xml.sax.helpers.XMLReaderFactory.createXMLReader () contains some very slow code.

If no classname is set as a system property, then the code underneath line 114 ("2. if that fails, try META-INF/services/") gets run. This gets the resource as stream and reads it in _every_ time that createXMLReader is called!

I changed the implementation of createXMLReader so as to cache the classname once it has been found the first time. This resulted in a 10-fold speed increase for my simple test case that calls MLReaderFactory.createXMLReader () 10,000 times.



REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import org.xml.sax.helpers.XMLReaderFactory;

public class XMLReaderTest {

  public static void main(String[] args) {
    try {
      int times = 10000;
      long start = System.currentTimeMillis();
      for(int i=0;i<times;i++) {
        XMLReaderFactory.createXMLReader();
      }
      long end = System.currentTimeMillis();
      double speed = ((end-start));
      System.out.println(speed+"ms");
    } catch (Throwable e) {
      e.printStackTrace();
    }
  }
}

---------- END SOURCE ----------