System.out.println(SystemUtil.OS_NAME);
        System.out.println(SystemUtil.JAVA_IO_TMPDIR);
        System.out.println(SystemUtil.USER_DIR);
        System.out.println(SystemUtil.USER_HOME);
    }

     */
    public static final String USER_DIR = System.getProperty("user.dir");

    /**
     * <code>user.home</code> system property.
     */
    public static final String USER_HOME = System.getProperty("user.home");

    /**
     * Returns the system property value for the specified key.
     *
     * @param key the property key
     * @return the property value, or null if not found
     */

  /** 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;
  }