content: package openjoe.smart.sso.server.util;
  
  import java.math.BigInteger;
  import java.security.MessageDigest;
  import java.security.NoSuchAlgorithmException;
  
  public class ClientCredentialsGenerator {
  
      public static String generateClientSecret(String clientId) {
          try {
              return md5(new StringBuilder(clientId).append(System.currentTimeMillis()).toString());
          } catch (Exception e) {
              throw new RuntimeException("Error generating client secret", e);
          }
      }
  
      private static String md5(String str) {
          String password = null;
          try {
              // 生成一个MD5加密计算摘要
              MessageDigest md = MessageDigest.getInstance("MD5");
              // 计算md5函数
              md.update(str.getBytes());
              // digest()最后确定返回md5 hash值，返回值为8为字符串。因为md5 hash值是16位的hex值，实际上就是8位的字符
              // BigInteger函数则将8位的字符串转换成16位hex值，用字符串来表示；得到字符串形式的hash值
              password = new BigInteger(1, md.digest()).toString(16);
          }
          catch (NoSuchAlgorithmException e) {
              e.printStackTrace();
          }
          return password;
      }
  
      public static void main(String[] args) {
          String clientId = "1000";
          System.err.println(generateClientSecret(clientId));
      }
  }
  