* being a real directory to being a symlink to another directory. It then calls
   * deleteDirectoryContents thousands of times on a directory whose subtree contains the file
   * that's switching between directory and symlink to try to ensure that under no circumstance does
   * deleteDirectoryContents follow the symlink to the other directory and delete that directory's
   * contents.
   *

 * a file or directory that would be more accessible.
 */
@J2ktIncompatible
@GwtIncompatible
@J2ObjCIncompatible
@ElementTypesAreNonnullByDefault
abstract class TempFileCreator {
  static final TempFileCreator INSTANCE = pickSecureCreator();

  /**
   * @throws IllegalStateException if the directory could not be created (to implement the contract

      try {
        try {
          urls.add(new File(entry).toURI().toURL());
        } catch (SecurityException e) { // File.toURI checks to see if the file is a directory
          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {
        AssertionError error = new AssertionError("malformed class path entry: " + entry);

  /** Line separator ("\n" on UNIX). */
  LINE_SEPARATOR("line.separator"),

  /** User's account name. */
  USER_NAME("user.name"),

  /** User's home directory. */
  USER_HOME("user.home"),

  /** User's current working directory. */
  USER_DIR("user.dir");

  private final String key;

  StandardSystemProperty(String key) {
    this.key = key;
  }

      try {
        try {
          urls.add(new File(entry).toURI().toURL());
        } catch (SecurityException e) { // File.toURI checks to see if the file is a directory
          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {
        AssertionError error = new AssertionError("malformed class path entry: " + entry);

      try {
        try {
          urls.add(new File(entry).toURI().toURL());
        } catch (SecurityException e) { // File.toURI checks to see if the file is a directory
          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {
        AssertionError error = new AssertionError("malformed class path entry: " + entry);

   * create a directory, not a regular file. A common pitfall is to call {@code createTempFile},
   * delete the file and create a directory in its place, but this leads a race condition which can
   * be exploited to create security vulnerabilities, especially when executable files are to be
   * written into the directory.
   *

    if (testFileUrl == null) {
      throw new RuntimeException("unable to locate testdata directory");
    }

    if (testFileUrl.getProtocol().equals("file")) {
      try {
        File testFile = new File(testFileUrl.toURI());
        testDir = testFile.getParentFile(); // the testdata directory
      } catch (Exception ignore) {
        // probably URISyntaxException or IllegalArgumentException

      currentPath.add(directory.getCanonicalFile());
      scanDirectory(directory, "", currentPath, builder);
    }

    /**
     * Recursively scan the given directory, adding resources for each file encountered. Symlinks
     * which have already been traversed in the current tree path will be skipped to eliminate
     * cycles; otherwise symlinks are traversed.
     *
     * @param directory the root of the directory to scan

      try {
        try {
          urls.add(new File(entry).toURI().toURL());
        } catch (SecurityException e) { // File.toURI checks to see if the file is a directory
          urls.add(new URL("file", null, new File(entry).getAbsolutePath()));
        }
      } catch (MalformedURLException e) {
        AssertionError error = new AssertionError("malformed class path entry: " + entry);