logback-android/src/main/java/ch/qos/logback/core/util/FileUtil.java
static public boolean createMissingParentDirectories(File file) {
    File parent = file.getParentFile();
    if (parent == null) {
      // Parent directory not specified, therefore it's a request to
      // create nothing. Done! ;)
      return true;
    }
    // File.mkdirs() creates the parent directories only if they don't
    // already exist; and it's okay if they do.
    parent.mkdirs();
    return parent.exists();
  }
static public boolean createMissingParentDirectories(File file) {
    File parent = file.getParentFile();
    if (parent == null) {
      // Parent directory not specified, therefore it's a request to
      // create nothing. Done! ;)
      return true;
    }
    // File.mkdirs() creates the parent directories only if they don't
    // already exist; and it's okay if they do.
    parent.mkdirs();
    return parent.exists();
  }
Creates the parent directories of a file. If parent directories not
specified in file's path, then nothing is done and this returns
gracefully.

@param file file whose parent directories (if any) should be created
@return {@code true} if either no parents were specified, or if all
parent directories were created successfully; {@code false} otherwise