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1   /*
2    * Copyright (c) 2011-2024 Qulice.com
3    *
4    * All rights reserved.
5    *
6    * Redistribution and use in source and binary forms, with or without
7    * modification, are permitted provided that the following conditions
8    * are met: 1) Redistributions of source code must retain the above
9    * copyright notice, this list of conditions and the following
10   * disclaimer. 2) Redistributions in binary form must reproduce the above
11   * copyright notice, this list of conditions and the following
12   * disclaimer in the documentation and/or other materials provided
13   * with the distribution. 3) Neither the name of the Qulice.com nor
14   * the names of its contributors may be used to endorse or promote
15   * products derived from this software without specific prior written
16   * permission.
17   *
18   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
20   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
22   * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29   * OF THE POSSIBILITY OF SUCH DAMAGE.
30   */
31  package com.qulice.checkstyle;
32  
33  import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
34  import com.puppycrawl.tools.checkstyle.api.FileText;
35  import java.io.File;
36  
37  /**
38   * Check if import lines are all together without any empty lines or comments.
39   *
40   * <p>All {@code import} instructions shall stay together, without any empty
41   * lines between them. If you need to separate them because the list is too
42   * big - it's time to refactor the class and make is smaller.
43   *
44   * @since 0.3
45   */
46  @SuppressWarnings("PMD.CyclomaticComplexity")
47  public final class ImportCohesionCheck extends AbstractFileSetCheck {
48  
49      /**
50       * The "import" keyword.
51       */
52      private static final String IMPORT = "import ";
53  
54      @Override
55      public void processFiltered(final File file, final FileText lines) {
56          int first = -1;
57          int last = -1;
58          for (int pos = 0; pos < lines.size(); pos += 1) {
59              final String line = lines.get(pos);
60              if (line.startsWith(ImportCohesionCheck.IMPORT)) {
61                  if (first == -1) {
62                      first = pos;
63                  }
64                  last = pos;
65              }
66          }
67          if (first == -1) {
68              return;
69          }
70          if (this.check(first, last, lines)) {
71              this.fireErrors(file.getPath());
72          }
73      }
74  
75      /**
76       * Perform check for empty lines and comments inside imports.
77       * @param first Line number where import occurred first
78       * @param last Line number where import occurred first
79       * @param lines All file line by line
80       * @return True if check is failed
81       */
82      private boolean check(final int first, final int last,
83          final FileText lines
84      ) {
85          boolean failure = false;
86          if (first == 0 || !lines.get(first - 1).isEmpty()) {
87              this.log(first, "Line before imports should be empty");
88              failure = true;
89          }
90          if (lines.size() > last + 1 && !lines.get(last + 1).isEmpty()) {
91              this.log(last + 2, "Line after imports should be empty");
92              failure = true;
93          }
94          for (int pos = first; pos < last; pos += 1) {
95              final String line = lines.get(pos);
96              if (!line.startsWith(ImportCohesionCheck.IMPORT)) {
97                  this.log(
98                      pos + 1,
99                      "Empty line or comment between imports is not allowed"
100                 );
101                 failure = true;
102             }
103         }
104         return failure;
105     }
106 
107 }