如何在Java 9中使用Process API终止/销毁进程?
在Java9中,ProcessAPI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