code: public static InputStream openKeyStore(String fileName) throws MalformedURLException, IOException {
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              Tr.entry(tc, "openKeyStore: " + fileName);
  
          URL urlFile = null;
  
          // Check if the filename exists as a File.
          File kfile = new File(fileName);
  
          if (kfile.exists() && kfile.length() == 0) {
              throw new IOException("Keystore file exists, but is empty: " + fileName);
          } else if (!kfile.exists()) {
              urlFile = new URL(fileName);
          } else {
              // kfile exists
              urlFile = new URL("file:" + kfile.getCanonicalPath());
          }
  
          // Finally open the file.
          InputStream fis = urlFile.openStream();
  
          if (TraceComponent.isAnyTracingEnabled() && tc.isEntryEnabled())
              Tr.exit(tc, "openKeyStore: " + (null != fis));
          return fis;
      }
docs: The purpose of this method is to open the passed in file which represents
  the key store.
  
  @param fileName
  @return InputStream
  @throws MalformedURLException
  @throws IOException