Java9ProcessAPI增强

在Java 9 Process API中，负责控制和管理操作系统进程的API已得到很大改进。 ProcessHandle类提供了检查进程活动性和销毁进程的方法。它具有onExit方法，CompletableFuture类可以在进程退出时异步执行操作。

import java.time.ZoneId;
import java.util.stream.Stream;
import java.util.stream.Collectors;
import java.io.IOException;

public class Tester {
   public static void main(String[] args) throws IOException {
      ProcessBuilder pb=new ProcessBuilder("notepad.exe");
      String np="Not Present";
      Process p=pb.start();
      ProcessHandle.Info info=p.info();
      System.out.printf("Process ID : %s%n", p.pid());
      System.out.printf("Command name : %s%n", info.command().orElse(np));
      System.out.printf("Command line : %s%n", info.commandLine().orElse(np));

      System.out.printf("Start time: %s%n",
         info.startInstant().map(i -> i.atZone(ZoneId.systemDefault())
         .toLocalDateTime().toString()).orElse(np));

      System.out.printf("Arguments : %s%n",
         info.arguments().map(a -> Stream.of(a).collect(
         Collectors.joining(" "))).orElse(np));

      System.out.printf("User : %s%n", info.user().orElse(np));
   } 
}

Process ID : 5800
Command name : C:\Windows\System32\notepad.exe
Command line : Not Present
Start time: 2017-11-04T21:35:03.626
Arguments : Not Present
User: administrator