content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.
   */
  
  package com.aliyun.oss.common.auth;
  
  /**
   * Default implementation of {@link CredentialsProvider}.
   */
  public class DefaultCredentialProvider implements CredentialsProvider {
  
      private volatile Credentials creds;
  
      public DefaultCredentialProvider(Credentials creds) {
          setCredentials(creds);
      }
  
      public DefaultCredentialProvider(String accessKeyId, String secretAccessKey) {
          this(accessKeyId, secretAccessKey, null);
      }
  
      public DefaultCredentialProvider(String accessKeyId, String secretAccessKey, String securityToken) {
          checkCredentials(accessKeyId, secretAccessKey);
          setCredentials(new DefaultCredentials(accessKeyId, secretAccessKey, securityToken));
      }
  
      @Override
      public synchronized void setCredentials(Credentials creds) {
          if (creds == null) {
              throw new InvalidCredentialsException("creds should not be null.");
          }
  
          checkCredentials(creds.getAccessKeyId(), creds.getSecretAccessKey());
          this.creds = creds;
      }
  
      @Override
      public Credentials getCredentials() {
          if (this.creds == null) {
              throw new InvalidCredentialsException("Invalid credentials");
          }
  
          return this.creds;
      }
  
      private static void checkCredentials(String accessKeyId, String secretAccessKey) {
          if (accessKeyId == null || accessKeyId.equals("")) {
              throw new InvalidCredentialsException("Access key id should not be null or empty.");
          }
  
          if (secretAccessKey == null || secretAccessKey.equals("")) {
              throw new InvalidCredentialsException("Secret access key should not be null or empty.");
          }
      }
  
  }
  