code: /**
   * This file is part of Eclipse Steady.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   * SPDX-License-Identifier: Apache-2.0
   * SPDX-FileCopyrightText: Copyright (c) 2018-2020 SAP SE or an SAP affiliate company and Eclipse Steady contributors
   */
  package org.eclipse.steady.backend.util;
  
  import java.nio.charset.StandardCharsets;
  
  import org.eclipse.steady.shared.enums.DigestAlgorithm;
  import org.eclipse.steady.shared.util.DigestUtil;
  
  /**
   * <p>TokenUtil class.</p>
   */
  public class TokenUtil {
  
    /**
     * Returns a random 64-char long token (MD5 hash generated over a randum
     * number and the current time milliseconds). Used for generating
     * {@link org.eclipse.steady.backend.model.Tenant} and
     * {@link org.eclipse.steady.backend.model.Space} tokens.
     *
     * @return a {@link java.lang.String} object.
     */
    public static String generateToken() {
      long rnd = (long) Math.abs(Math.random() * 100000000);
      long ms = System.currentTimeMillis();
      return DigestUtil.getDigestAsString(
          rnd + "-" + ms, StandardCharsets.UTF_8, DigestAlgorithm.MD5);
    }
  }
  