How to get commandLine & arguments of Process in Java 9

Question

Java 9 provied pretty way to get information of the Process, but I still don't know how to get the CommandLine & arguments of the process:

Process p = Runtime.getRuntime().exec("notepad.exe E:\\test.txt");
ProcessHandle.Info info = p.toHandle().info();
String[] arguments = info.arguments().orElse(new String[]{});
System.out.println("Arguments : " + arguments.length);
System.out.println("Command : " + info.command().orElse("")); 
System.out.println("CommandLine : " + info.commandLine().orElse(""));

Result:

Arguments : 0
Command : C:\Windows\System32\notepad.exe
CommandLine : 

But I am expecting:

Arguments : 1
Command : C:\Windows\System32\notepad.exe
CommandLine : C:\Windows\System32\notepad.exe E:\\test.txt

Answer 1

JDK-8176725 indicates that this feature is not implemented yet for Windows. Here is an easy but slow workaround:

  /**
   * Returns the full command-line of the process.
   * <p>
   * This is a workaround for
   * <a href="https://stackoverflow.com/a/46768046/14731">https://stackoverflow.com/a/46768046/14731</a>
   *
   * @param processHandle a process handle
   * @return the command-line of the process
   * @throws UncheckedIOException if an I/O error occurs
   */
  private Optional<String> getCommandLine(ProcessHandle processHandle) throws UncheckedIOException {
    if (!isWindows) {
      return processHandle.info().commandLine();
    }
    long desiredProcessid = processHandle.pid();
    try {
      Process process = new ProcessBuilder("wmic", "process", "where", "ProcessID=" + desiredProcessid, "get",
        "commandline", "/format:list").
        redirectErrorStream(true).
        start();
      try (InputStreamReader inputStreamReader = new InputStreamReader(process.getInputStream());
           BufferedReader reader = new BufferedReader(inputStreamReader)) {
        while (true) {
          String line = reader.readLine();
          if (line == null) {
            return Optional.empty();
          }
          if (!line.startsWith("CommandLine=")) {
            continue;
          }
          return Optional.of(line.substring("CommandLine=".length()));
        }
      }
    } catch (IOException e) {
      throw new UncheckedIOException(e);
    }
  }