1 /*
2 * Copyright (c) 2011-2025 Yegor Bugayenko
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 }