### Question:
TokenUtils { public static PublicKey readPublicKey(String pemResName) throws Exception { InputStream contentIS = TokenUtils.class.getResourceAsStream(pemResName); byte[] tmp = new byte[4096]; int length = contentIS.read(tmp); PublicKey publicKey = decodePublicKey(new String(tmp, 0, length)); return publicKey; } private  TokenUtils(); static String generateTokenString(String jsonResName); static String generateTokenString(String jsonResName, Set<InvalidClaims> invalidClaims); static String generateTokenString(String jsonResName, Set<InvalidClaims> invalidClaims, Map<String, Long> timeClaims); static PrivateKey readPrivateKey(String pemResName); static PublicKey readPublicKey(String pemResName); static KeyPair generateKeyPair(int keySize); static PrivateKey decodePrivateKey(String pemEncoded); static PublicKey decodePublicKey(String pemEncoded);  }### Answer:
@Test public void testReadPublicKey() throws Exception { RSAPublicKey publicKey = (RSAPublicKey) TokenUtils.readPublicKey("/publicKey.pem"); System.out.println(publicKey); System.out.printf("RSAPublicKey.bitLength: %s\n", publicKey.getModulus().bitLength()); }