Java: How to scan ide output for the highest number?

Question

So i have this code which prints out the running processes from task manager to the ide in netbeans but i'd like to scan the output of processes so i can list the highest running process on my PC at the time?

public static void main(String[] args) throws IOException {
  try {
   String tasklist;
   Process p = Runtime.getRuntime().exec
    (System.getenv("windir") +"\\system32\\"+"tasklist.exe");
    try (BufferedReader input = new BufferedReader(new   InputStreamReader(p.getInputStream()))) {
      while ((tasklist = input.readLine()) != null) {
      System.out.println(tasklist); //<-- Parse data here.
  }
}
} catch (IOException err) {
  err.printStackTrace();
} 
}

This give me the below output for example and if i'd like to kill netbeans because it's running over 500,000k how would i do that?

Image Name                     PID Session Name        Session    Mem Usage

chrome.exe                    3464 Console                    3    159,672 K
netbeans64.exe                3664 Console                    3    592,216 K
chrome.exe                    3808 Console                    3    384,556 K
java.exe                      2040 Console                    3     36,732 K
tasklist.exe                  2208 Console                    3      6,196 K

Well, if you are running this *inside* netbeans, you had better not kill it or you won't be able to see the list anymore... In any case, in your program, you have the `tasklist` line. Parse it into meaningful data, put it in a list of objects, sort it, and do whatever you need with the sorted list. — RealSkeptic, Mar 01 '17 at 13:48
And hint: feel free to give feedback to my answer via comments. I have seen it too often the last days that some newbie asks a questions ... and doesn't ever come back. No comment, no upvote, no accept. So, please consider providing some form of feedback ;-) — GhostCat, Mar 01 '17 at 13:59
Example, now that you reach upvote rep, you could upvote ... and leave a comment ;-) — GhostCat, Mar 01 '17 at 14:07

score 4 · Accepted Answer · edited May 23 '17 at 12:25

You iterate that data; and collect those attributes that you are interested in; for example name, PID, and of course, mem usage.

You would probably create a class like

public class RunningProcessInfo {
  private final String name ...

  public RunningProcessInfo(String name, int pid, int memUsage) {

In other words: you write parsing code that takes a line as

chrome.exe 3464 Console 3 159,672 K

and turns that into

new RunningProcessInfo("chrome.exe", 3464, 159672)

(by parsing the string input; and turning strings like "3464" into numbers, and so on).

Meaning: you replace the line System.out.println(tasklist); with something along the lines of

processInfos.add( parseLine(tasklist) );

with processInfos being some ArrayList<RunningProcessInfo> and parseLine() being that method that takes a single line and fetches the data to build a new RunningProcessInfo object.

You collect those objects in a list. Then you iterate that list to find all objects that meet a certain criteria.

Finally you use another process builder to send a command to kill those PIDs you intend to kill ( see here for examples how to do that ). And of course, you pay attention - as you for sure do not want to kill your netbeans session while that session is running your program ...

Thanks for the help and quick response! Have you got any recommendations for iterating my data to collect the attributes? — Codeo, Mar 01 '17 at 14:19
I enhanced the answer about the "looping" part (as that is already there). The the parsing, you can get ideas here http://stackoverflow.com/questions/11871520/how-can-i-read-input-from-the-console-using-the-scanner-class-in-java (you can use a scanner; just not in System.in; but your file) or you go with a tokenizer: http://stackoverflow.com/questions/691184/scanner-vs-stringtokenizer-vs-string-split ... many options; up to you. So, please step back, and digest this first; and when you have a really specific question ... write up a new one. — GhostCat, Mar 01 '17 at 14:28

Java: How to scan ide output for the highest number?

1 Answers1