code: public static PublicKey decryptPublicKey(String publicKeyStr) {
          try {
              KeyFactory keyFactory = KeyFactory.getInstance(algorithm);
              X509EncodedKeySpec keySpec = new X509EncodedKeySpec(Base64Util.decode(publicKeyStr));
              return keyFactory.generatePublic(keySpec);
          } catch (NoSuchAlgorithmException e) {
              e.printStackTrace();
          } catch (InvalidKeySpecException e) {
              e.printStackTrace();
          }
          return null;
      }
docs: 从Base64字符中解出公钥
  <p>Function: decryptPublicKey</p>
  <p>Description: </p>
  
  @param publicKeyStr
  @return
  @author acexy@thankjava.com
  @date 2016年8月11日 上午9:50:30
  @version 1.0