How to get all children of a process using Process API in Java 9?

Process handling classes and related API have been introduced in Java 9. We can use the ProcessHandle interface and related methods to get pid and information about other related processes. We need to get all children of a process, then use java.lang.ProcessHandle.children() method. This method returns a stream, typically a process that has no children.

In the below example, we can get the first process and retrieve its children's process information.

Example

import java.util.stream.Stream;
import java.util.Optional;

public class ChilderenProcessTest {
   public static void main(String args[]) throws InterruptedException {
      System.out.println("---------------------------");
      System.out.println("Children Processes:");
      Optional<ProcessHandle> processHandle = ProcessHandle.allProcesses().findFirst();
      processHandle.ifPresent(proc -> proc.children().forEach(child -> System.out.println("PID: [ " + child.pid() + " ], Cmd: [ " + child.info().command() + " ]")));
   }
}

Output

---------------------------
Children Processes:
PID: [ 0 ], Cmd: [ Optional.empty ]
PID: [ 4 ], Cmd: [ Optional.empty ]
PID: [ 424 ], Cmd: [ Optional.empty ]
PID: [ 504 ], Cmd: [ Optional.empty ]
PID: [ 560 ], Cmd: [ Optional.empty ]
PID: [ 444 ], Cmd: [ Optional.empty ]
PID: [ 1236 ], Cmd: [ Optional.empty ]
PID: [ 1288 ], Cmd: [ Optional.empty ]
PID: [ 1408 ], Cmd: [ Optional.empty ]
PID: [ 1424 ], Cmd: [ Optional.empty ]
PID: [ 1452 ], Cmd: [ Optional.empty ]
PID: [ 1468 ], Cmd: [ Optional.empty ]
PID: [ 5412 ], Cmd: [ Optional[C:\WINDOWS\System32\taskhostex.exe] ]
PID: [ 3760 ], Cmd: [ Optional[C:\Program Files\Synaptics\SynTP\SynTPEnh.exe] ]
PID: [ 5216 ], Cmd: [ Optional[C:\WINDOWS\explorer.exe] ]
PID: [ 2460 ], Cmd: [ Optional[C:\Program Files (x86)\Dell Wireless\Bluetooth Suite\BtvStack.exe] ]
PID: [ 6064 ], Cmd: [ Optional[C:\Program Files\Realtek\Audio\HDA\RtkNGUI64.exe] ]
PID: [ 7172 ], Cmd: [ Optional[C:\Program Files (x86)\Google\Chrome\Application\chrome.exe] ]
PID: [ 860 ], Cmd: [ Optional[C:\Program Files (x86)\Google\Chrome\Application\chrome.exe] ]
PID: [ 9000 ], Cmd: [ Optional.empty ]
PID: [ 4180 ], Cmd: [ Optional[C:\WINDOWS\System32\cmd.exe] ]
PID: [ 3748 ], Cmd: [ Optional[C:\WINDOWS\System32\conhost.exe] ]
PID: [ 3376 ], Cmd: [ Optional.empty ]
PID: [ 2548 ], Cmd: [ Optional.empty ]
PID: [ 1820 ], Cmd: [ Optional[C:\Program Files\Java\jdk-9.0.4\bin\java.exe] ]

Raja

Published on 06-Mar-2020 22:53:41