FileNullCheck.java

package os;

import java.io.File;
import java.io.IOException;

public class FileNullCheck
{
    public static void main(String[] args)
    {
        File tmp = new File("a.jsp");
        try
        {
            tmp.createNewFile();
        }
        catch (IOException e)
        {
            e.printStackTrace();
            return;
        }
        
        String a = "a.jsp";
        System.out.printf("a.jsp exists: %b (len=%d)%n",new File(a).exists(),a.length());
        
        String anull = new String(new byte[] { 'a', '.', 'j', 's', 'p', 0x00 });
        System.out.printf("a.jsp (null) exists: %b (len=%d)%n",new File(anull).exists(),anull.length());

        String anullx = new String(new byte[] { 'a', '.', 'j', 's', 'p', 0x00, 'x' });
        System.out.printf("a.jsp (nullx) exists: %b (len=%d)%n",new File(anullx).exists(),anullx.length());
    }
}


/* returns the following

a.jsp exists: true (len=5)
a.jsp (null) exists: true (len=6)
a.jsp (nullx) exists: true (len=7)

*/