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1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2017 the original author or authors.
4   //
5   // This library is free software; you can redistribute it and/or
6   // modify it under the terms of the GNU Lesser General Public
7   // License as published by the Free Software Foundation; either
8   // version 2.1 of the License, or (at your option) any later version.
9   //
10  // This library is distributed in the hope that it will be useful,
11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  // Lesser General Public License for more details.
14  //
15  // You should have received a copy of the GNU Lesser General Public
16  // License along with this library; if not, write to the Free Software
17  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  ////////////////////////////////////////////////////////////////////////////////
19  
20  package com.puppycrawl.tools.checkstyle.checks;
21  
22  import java.nio.charset.StandardCharsets;
23  import java.util.Arrays;
24  
25  /**
26   * Represents the options for line separator settings.
27   *
28   * @author lkuehne
29   * @see NewlineAtEndOfFileCheck
30   */
31  public enum LineSeparatorOption {
32      /** Windows-style line separators. **/
33      CRLF("\r\n"),
34  
35      /** Mac-style line separators. **/
36      CR("\r"),
37  
38      /** Unix-style line separators. **/
39      LF("\n"),
40  
41      /**
42       * Matches CR, LF and CRLF line separators.
43       * Only the length is used - the actual value is ignored.
44       */
45      LF_CR_CRLF("##"),
46  
47      /** System default line separators. **/
48      SYSTEM(System.getProperty("line.separator"));
49  
50      /** The line separator representation. */
51      private final byte[] lineSeparator;
52  
53      /**
54       * Creates a new {@code LineSeparatorOption} instance.
55       * @param sep the line separator, e.g. "\r\n"
56       */
57      LineSeparatorOption(String sep) {
58          lineSeparator = sep.getBytes(StandardCharsets.US_ASCII);
59      }
60  
61      /**
62       * Checks that bytes is equal to the byte representation of this line separator.
63       * @param bytes a bytes array to check
64       * @return if bytes is equal to the byte representation
65       *     of this line separator
66       */
67      public boolean matches(byte... bytes) {
68          final boolean result;
69          if (this == LF_CR_CRLF) {
70              // this silently assumes CRLF and ANY have the same length
71              // and LF and CR are of length 1
72              result = CRLF.matches(bytes)
73                  || LF.matches(Arrays.copyOfRange(bytes, 1, 2))
74                  || CR.matches(Arrays.copyOfRange(bytes, 1, 2));
75          }
76          else {
77              result = Arrays.equals(bytes, lineSeparator);
78          }
79          return result;
80      }
81  
82      /**
83       * Returns length of file separator in bytes.
84       * @return the length of the file separator in bytes,
85       *     e.g. 1 for CR, 2 for CRLF, ...
86       */
87      public int length() {
88          return lineSeparator.length;
89      }
90  }