Java / Junit: how to test if an external program/process/application is running?

Question

I have a Junit / Silkuli test that runs on windows 7 and is dependent on an external program already running.

How can I check if the external program is running from inside the test?

Answer 1

You can run command "tasklist" from within java and look at the returned list to see if your program is in the list. something like:

String program = "eclipse.exe";   //or any other process
String listOfProcesses = getCommandOutput("tasklist");
 if (listOfProcesses == null || listOfProcesses.isEmpty()) {
        System.err.println("Unable to automatically determine if " + program + " is running");
    } else {
        if (listOfProcesses.contains(program)) {
            System.out.println(program + " is running!");
        } else {
            System.out.println(program + " is not running!");
        }
    }//else: process list can be retrieved

and get the output from a command using a method such as:

public static String getCommandOutput(String command)  {
    String output = null;       //the string to return

    Process process = null;
    BufferedReader reader = null;
    InputStreamReader streamReader = null;
    InputStream stream = null;

    try {
        process = Runtime.getRuntime().exec(command);

        //Get stream of the console running the command
        stream = process.getInputStream();
        streamReader = new InputStreamReader(stream);
        reader = new BufferedReader(streamReader);

        String currentLine = null;  //store current line of output from the cmd
        StringBuilder commandOutput = new StringBuilder();  //build up the output from cmd
        while ((currentLine = reader.readLine()) != null) {
            commandOutput.append(currentLine + "\n");
        }

        int returnCode = process.waitFor();
        if (returnCode == 0) {
            output = commandOutput.toString();
        }

    } catch (IOException e) {
        System.err.println("Cannot retrieve output of command");
        System.err.println(e);
        output = null;
    } catch (InterruptedException e) {
        System.err.println("Cannot retrieve output of command");
        System.err.println(e);
    } finally {
        //Close all inputs / readers

        if (stream != null) {
            try {
                stream.close();
            } catch (IOException e) {
                System.err.println("Cannot close stream input! " + e);
            }
        } 
        if (streamReader != null) {
            try {
                streamReader.close();
            } catch (IOException e) {
                System.err.println("Cannot close stream input reader! " + e);
            }
        }
        if (reader != null) {
            try {
                reader.close();
            } catch (IOException e) {
                System.err.println("Cannot close reader! " + e);
            }
        }
    }
    //Return the output from the command - may be null if an error occured
    return output;
}