1. sun.io.useCanonPrefixCache cannot be disabled.

    private static boolean getBooleanProperty(String prop, boolean defaultVal) {
        String val = System.getProperty("sun.io.useCanonCaches");

  "sun.io.useCanonCaches" should be prop

2. For an existing file, getCanonicalPath() sometimes can produce
a pathname whose case doesn't match that of the existing file's pathname.
This doesn't matter in terms of being able to access the file, but it appears
that some applications, such as TomCat, depend on getting the correct case.
Sometimes the answer for the same input is inconsistent. Here's the
test program from the customer.

import java.io.*;

public class Test {

    public static void main(String args[]) {
        
        File test = null;
        test = new File("foo/Test.txt");
        try {
            System.out.println("Can path: " + test.getCanonicalPath())
;
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        test = new File("foo/test.Txt");
        try {
            System.out.println("Can path: " + test.getCanonicalPath())
;
        } catch (Exception e) {
            e.printStackTrace();
        }
        test = new File("foo/Test.Txt");
        try {
            System.out.println("Can path: " + test.getCanonicalPath())
;
        } catch (Exception e) {
            e.printStackTrace();
        }
        
    }

}

touch foo\test.txt
rm -f foo\Test.txt

On 1.4.2, this produces
c:\foo\test.txt
c:\foo\test.txt
c:\foo\Test.txt

With the cache disabled, it produces
c:\foo\test.txt
c:\foo\test.txt
c:\foo\test.txt

It is strange that #1 and #3 are different when the cache is enabled.

rm -f foo\test.txt
touch foo\Test.txt

1.4.2 with cache enabled produces:
c:\foo\Test.txt
c:\foo\test.txt
c:\foo\Test.txt

Cache disabled:
c:\foo\Test.txt
c:\foo\Test.txt
c:\foo\Test.txt