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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  
20  package org.apache.shiro.lang.util;
21  
22  import java.io.Closeable;
23  import java.io.IOException;
24  
25  /**
26   * To use try-with-resources idiom, this class supports wrapping existing ByteSource
27   * object or byte array. At end of try block, it gets zeroed out automatically.
28   */
29  public final class ByteSourceWrapper implements Closeable {
30      private final byte[] bytes;
31  
32      private ByteSourceWrapper(byte[] bytes) {
33          this.bytes = bytes;
34      }
35  
36      /**
37       * This method generically accepts byte array or ByteSource instance.
38       */
39      public static ByteSourceWrapper wrap(Object value) {
40          if (value instanceof byte[]) {
41              byte[] bytes = (byte[]) value;
42              return new ByteSourceWrapper(bytes);
43          } else if (value instanceof ByteSource) {
44              byte[] bytes = ((ByteSource) value).getBytes();
45              return new ByteSourceWrapper(bytes);
46          }
47          throw new IllegalArgumentException();
48      }
49  
50      public byte[] getBytes() {
51          return bytes;
52      }
53  
54      public void close() throws IOException {
55          ByteUtils.wipe(bytes);
56      }
57  }