| 1 | package be.nikiroo.utils; |
| 2 | |
| 3 | import java.io.Closeable; |
| 4 | import java.io.File; |
| 5 | import java.io.IOException; |
| 6 | |
| 7 | /** |
| 8 | * A small utility class to generate auto-delete temporary files in a |
| 9 | * centralised location. |
| 10 | * |
| 11 | * @author niki |
| 12 | */ |
| 13 | public class TempFiles implements Closeable { |
| 14 | /** |
| 15 | * Root directory of this instance, owned by it, where all temporary files |
| 16 | * must reside. |
| 17 | */ |
| 18 | protected File root; |
| 19 | |
| 20 | /** |
| 21 | * Create a new {@link TempFiles} -- each instance is separate and have a |
| 22 | * dedicated sub-directory in a shared temporary root. |
| 23 | * <p> |
| 24 | * The whole repository will be deleted on close (if you fail to call it, |
| 25 | * the program will <b>try</b> to call it on JVM termination). |
| 26 | * |
| 27 | * @param name |
| 28 | * the instance name (will be <b>part</b> of the final directory |
| 29 | * name) |
| 30 | * |
| 31 | * @throws IOException |
| 32 | * in case of I/O error |
| 33 | */ |
| 34 | public TempFiles(String name) throws IOException { |
| 35 | this(null, name); |
| 36 | } |
| 37 | |
| 38 | /** |
| 39 | * Create a new {@link TempFiles} -- each instance is separate and have a |
| 40 | * dedicated sub-directory in a given temporary root. |
| 41 | * <p> |
| 42 | * The whole repository will be deleted on close (if you fail to call it, |
| 43 | * the program will <b>try</b> to call it on JVM termination). |
| 44 | * <p> |
| 45 | * Be careful, this instance will <b>own</b> the given root directory, and |
| 46 | * will most probably delete all its files. |
| 47 | * |
| 48 | * @param base |
| 49 | * the root base directory to use for all the temporary files of |
| 50 | * this instance (if NULL, will be the default temporary |
| 51 | * directory of the OS) |
| 52 | * @param name |
| 53 | * the instance name (will be <b>part</b> of the final directory |
| 54 | * name) |
| 55 | * |
| 56 | * @throws IOException |
| 57 | * in case of I/O error |
| 58 | */ |
| 59 | public TempFiles(File base, String name) throws IOException { |
| 60 | if (base == null) { |
| 61 | base = File.createTempFile(".temp", ""); |
| 62 | } |
| 63 | |
| 64 | root = base; |
| 65 | |
| 66 | if (root.exists()) { |
| 67 | IOUtils.deltree(root, true); |
| 68 | } |
| 69 | |
| 70 | root = new File(root.getParentFile(), ".temp"); |
| 71 | root.mkdir(); |
| 72 | if (!root.exists()) { |
| 73 | throw new IOException("Cannot create root directory: " + root); |
| 74 | } |
| 75 | |
| 76 | root.deleteOnExit(); |
| 77 | |
| 78 | root = createTempFile(name); |
| 79 | IOUtils.deltree(root, true); |
| 80 | |
| 81 | root.mkdir(); |
| 82 | if (!root.exists()) { |
| 83 | throw new IOException("Cannot create root subdirectory: " + root); |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Create an auto-delete temporary file. |
| 89 | * |
| 90 | * @param name |
| 91 | * a base for the final filename (only a <b>part</b> of said |
| 92 | * filename) |
| 93 | * |
| 94 | * @return the newly created file |
| 95 | * |
| 96 | * @throws IOException |
| 97 | * in case of I/O errors |
| 98 | */ |
| 99 | public synchronized File createTempFile(String name) throws IOException { |
| 100 | name += "_"; |
| 101 | while (name.length() < 3) { |
| 102 | name += "_"; |
| 103 | } |
| 104 | |
| 105 | while (true) { |
| 106 | File tmp = File.createTempFile(name, ""); |
| 107 | IOUtils.deltree(tmp, true); |
| 108 | |
| 109 | File test = new File(root, tmp.getName()); |
| 110 | if (!test.exists()) { |
| 111 | test.createNewFile(); |
| 112 | if (!test.exists()) { |
| 113 | throw new IOException( |
| 114 | "Cannot create temporary file: " + test); |
| 115 | } |
| 116 | |
| 117 | test.deleteOnExit(); |
| 118 | return test; |
| 119 | } |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Create an auto-delete temporary directory. |
| 125 | * <p> |
| 126 | * Note that creating 2 temporary directories with the same name will result |
| 127 | * in two <b>different</b> directories, even if the final name is the same |
| 128 | * (the absolute path will be different). |
| 129 | * |
| 130 | * @param name |
| 131 | * the actual directory name (not path) |
| 132 | * |
| 133 | * @return the newly created file |
| 134 | * |
| 135 | * @throws IOException |
| 136 | * in case of I/O errors, or if the name was a path instead of a |
| 137 | * name |
| 138 | */ |
| 139 | public synchronized File createTempDir(String name) throws IOException { |
| 140 | File localRoot = createTempFile(name); |
| 141 | IOUtils.deltree(localRoot, true); |
| 142 | |
| 143 | localRoot.mkdir(); |
| 144 | if (!localRoot.exists()) { |
| 145 | throw new IOException("Cannot create subdirectory: " + localRoot); |
| 146 | } |
| 147 | |
| 148 | File dir = new File(localRoot, name); |
| 149 | if (!dir.getName().equals(name)) { |
| 150 | throw new IOException( |
| 151 | "Cannot create temporary directory with a path, only names are allowed: " |
| 152 | + dir); |
| 153 | } |
| 154 | |
| 155 | dir.mkdir(); |
| 156 | dir.deleteOnExit(); |
| 157 | |
| 158 | if (!dir.exists()) { |
| 159 | throw new IOException("Cannot create subdirectory: " + dir); |
| 160 | } |
| 161 | |
| 162 | return dir; |
| 163 | } |
| 164 | |
| 165 | @Override |
| 166 | public synchronized void close() throws IOException { |
| 167 | File root = this.root; |
| 168 | this.root = null; |
| 169 | |
| 170 | if (root != null) { |
| 171 | IOUtils.deltree(root); |
| 172 | |
| 173 | // Since we allocate temp directories from a base point, |
| 174 | // try and remove that base point |
| 175 | root.getParentFile().delete(); // (only works if empty) |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | @Override |
| 180 | protected void finalize() throws Throwable { |
| 181 | try { |
| 182 | close(); |
| 183 | } finally { |
| 184 | super.finalize(); |
| 185 | } |
| 186 | } |
| 187 | } |