How to get a list of current open windows/process with Java?
This is another approach to parse the the process list from the command "ps -e":
try {
String line;
Process p = Runtime.getRuntime().exec("ps -e");
BufferedReader input =
new BufferedReader(new InputStreamReader(p.getInputStream()));
while ((line = input.readLine()) != null) {
System.out.println(line); //<-- Parse data here.
}
input.close();
} catch (Exception err) {
err.printStackTrace();
}
If you are using Windows, then you should change the line: "Process p = Runtime.getRun..." etc... (3rd line), for one that looks like this:
Process p = Runtime.getRuntime().exec
(System.getenv("windir") +"\\system32\\"+"tasklist.exe");
Hope the info helps!
Finally, with Java 9+ it is possible with ProcessHandle
:
public static void main(String[] args) {
ProcessHandle.allProcesses()
.forEach(process -> System.out.println(processDetails(process)));
}
private static String processDetails(ProcessHandle process) {
return String.format("%8d %8s %10s %26s %-40s",
process.pid(),
text(process.parent().map(ProcessHandle::pid)),
text(process.info().user()),
text(process.info().startInstant()),
text(process.info().commandLine()));
}
private static String text(Optional<?> optional) {
return optional.map(Object::toString).orElse("-");
}
Output:
1 - root 2017-11-19T18:01:13.100Z /sbin/init
...
639 1325 www-data 2018-12-04T06:35:58.680Z /usr/sbin/apache2 -k start
...
23082 11054 huguesm 2018-12-04T10:24:22.100Z /.../java ProcessListDemo
On Windows there is an alternative using JNA:
import com.sun.jna.Native;
import com.sun.jna.platform.win32.*;
import com.sun.jna.win32.W32APIOptions;
public class ProcessList {
public static void main(String[] args) {
WinNT winNT = (WinNT) Native.loadLibrary(WinNT.class, W32APIOptions.UNICODE_OPTIONS);
WinNT.HANDLE snapshot = winNT.CreateToolhelp32Snapshot(Tlhelp32.TH32CS_SNAPPROCESS, new WinDef.DWORD(0));
Tlhelp32.PROCESSENTRY32.ByReference processEntry = new Tlhelp32.PROCESSENTRY32.ByReference();
while (winNT.Process32Next(snapshot, processEntry)) {
System.out.println(processEntry.th32ProcessID + "\t" + Native.toString(processEntry.szExeFile));
}
winNT.CloseHandle(snapshot);
}
}