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1 /* |
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2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 package java.nio.file; |
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27 |
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28 import java.io.Closeable; |
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29 import java.io.IOException; |
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30 import java.io.UncheckedIOException; |
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31 import java.util.Arrays; |
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32 import java.util.Iterator; |
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33 import java.util.NoSuchElementException; |
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34 import java.util.Objects; |
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35 import java.nio.file.FileTreeWalker.Event; |
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36 |
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37 /** |
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38 * An {@code Iterator to iterate over the nodes of a file tree. |
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39 * |
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40 * <pre>{@code |
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41 * try (FileTreeIterator iterator = new FileTreeIterator(start, maxDepth, options)) { |
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42 * while (iterator.hasNext()) { |
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43 * Event ev = iterator.next(); |
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44 * Path path = ev.file(); |
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45 * BasicFileAttributes attrs = ev.attributes(); |
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46 * } |
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47 * } |
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48 * }</pre> |
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49 */ |
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50 |
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51 class FileTreeIterator implements Iterator<Event>, Closeable { |
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52 private final FileTreeWalker walker; |
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53 private Event next; |
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54 |
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55 /** |
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56 * Creates a new iterator to walk the file tree starting at the given file. |
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57 * |
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58 * @throws IllegalArgumentException |
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59 * if {@code maxDepth} is negative |
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60 * @throws IOException |
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61 * if an I/O errors occurs opening the starting file |
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62 * @throws SecurityException |
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63 * if the security manager denies access to the starting file |
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64 * @throws NullPointerException |
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65 * if {@code start} or {@code options} is {@ocde null} or |
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66 * the options array contains a {@code null} element |
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67 */ |
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68 FileTreeIterator(Path start, int maxDepth, FileVisitOption... options) |
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69 throws IOException |
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70 { |
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71 this.walker = new FileTreeWalker(Arrays.asList(options), maxDepth); |
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72 this.next = walker.walk(start); |
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73 assert next.type() == FileTreeWalker.EventType.ENTRY || |
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74 next.type() == FileTreeWalker.EventType.START_DIRECTORY; |
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75 |
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76 // IOException if there a problem accessing the starting file |
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77 IOException ioe = next.ioeException(); |
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78 if (ioe != null) |
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79 throw ioe; |
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80 } |
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81 |
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82 private void fetchNextIfNeeded() { |
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83 if (next == null) { |
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84 FileTreeWalker.Event ev = walker.next(); |
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85 while (ev != null) { |
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86 IOException ioe = ev.ioeException(); |
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87 if (ioe != null) |
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88 throw new UncheckedIOException(ioe); |
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89 |
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90 // END_DIRECTORY events are ignored |
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91 if (ev.type() != FileTreeWalker.EventType.END_DIRECTORY) { |
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92 next = ev; |
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93 return; |
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94 } |
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95 ev = walker.next(); |
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96 } |
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97 } |
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98 } |
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99 |
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100 @Override |
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101 public boolean hasNext() { |
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102 if (!walker.isOpen()) |
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103 throw new IllegalStateException(); |
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104 fetchNextIfNeeded(); |
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105 return next != null; |
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106 } |
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107 |
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108 @Override |
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109 public Event next() { |
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110 if (!walker.isOpen()) |
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111 throw new IllegalStateException(); |
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112 fetchNextIfNeeded(); |
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113 if (next == null) |
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114 throw new NoSuchElementException(); |
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115 Event result = next; |
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116 next = null; |
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117 return result; |
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118 } |
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119 |
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120 @Override |
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121 public void close() { |
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122 walker.close(); |
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123 } |
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124 } |