如何在Java 9中使用Process API终止/销毁进程?

在Java 9中,Process API支持一种简单的方法来获取有关流程的更多信息。ProcessHandle 接口可以标识并提供对本地进程和方法的控制,以检查进程的活动性并销毁进程,而ProcessHandle.Info接口可以提供进程的信息快照。我们需要使用ProcessHandle 接口的destroy()方法销毁一个进程。

在下面的示例中,我们需要使用ProcessHandle 接口终止进程。

示例

import java.io.File;
import java.io.IOException;
import java.util.Objects;

public class DestroyProcessTest {
   public static void main(String[] args) throws InterruptedException {
      System.out.println("---------------------------");
      System.out.println("Destroy Process:");

      final String javaCmd = getJavaCmdFromParent();
      final String classpath = getClassPathFromParent();

      try {
         final Process process = new ProcessBuilder(javaCmd, "-cp", classpath, DestroyProcessTest.class.getName()).start();
         ProcessHandle processHandle = process.toHandle();
         printInfo(processHandle);
         destroyProcess(processHandle);

         Thread.sleep(1000);
         System.out.println("---------------------------");
         System.out.println("After destroying the process:");
         printInfo(processHandle);

      } catch(IOException e) {
         e.printStackTrace();
      }
   }
   private static String getClassPathFromParent() {
      return System.getProperty("java.class.path", "./*");
   }
   private static String getJavaCmdFromParent() {
      return Objects.isNull(System.getProperty("java.home")) ? "java"
: String.format("%s%sbin%sjava", System.getProperty("java.home"), File.separator, File.separator);
   }
   private static void destroyProcess(ProcessHandle processHandle) throws IllegalStateException {
      System.out.println("Ready to destroy Process with id: " + processHandle.pid());
      processHandle.destroy();
   }
   private static void printInfo(ProcessHandle processHandle) {
      System.out.println("---------");
      System.out.println("Id: " + processHandle.pid());
      System.out.println("isAlive(): " + processHandle.isAlive());
      System.out.println("isSupportsNormalTermination(): " + processHandle.supportsNormalTermination());

      ProcessHandle.Info processInfo = processHandle.info();
      System.out.println("Info: " + processInfo.toString());
      System.out.println("Info arguments().isPresent(): " + processInfo.arguments().isPresent());
      System.out.println("Info command().isPresent(): " + processInfo.command().isPresent());
      System.out.println("Info totalCpuDuration().isPresent(): " + processInfo.totalCpuDuration().isPresent());
      System.out.println("Info user().isPresent(): " + processInfo.user().isPresent());
   }
}

输出结果

---------------------------
Destroy Process:
---------
Id: 4384
isAlive(): true
isSupportsNormalTermination(): false
Info: [user: Optional[Nhooo\User], cmd: C:\Program Files\Java\jdk-9.0.4\bin\java.exe, startTime: Optional[2020-03-06T10:58:53.210Z], totalTime: Optional[PT0.046875S]]
Info arguments().isPresent(): false
Info command().isPresent(): true
Info totalCpuDuration().isPresent(): true
Info user().isPresent(): true
Ready to destroy Process with id: 4384
---------------------------
After destroying the process:
---------
Id: 4384
isAlive(): false
isSupportsNormalTermination(): false
Info: [user: Optional[Nhooo\User], startTime: Optional[2020-03-06T10:58:53.210Z], totalTime: Optional[PT0.109375S]]
Info arguments().isPresent(): false
Info command().isPresent(): false
Info totalCpuDuration().isPresent(): true
Info user().isPresent(): true