Sources

Faire un journal court pourquoi pas mais mettre les sources dedans serait quand même plus agréable pour ceux qui veulent lire ce que tu as fait :

package com.i2bp.taptempo;
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.CommandLineParser;
import org.apache.commons.cli.DefaultParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;
import java.text.DecimalFormat;
import java.util.Scanner;
import java.util.ArrayDeque;
import java.util.Date;
import java.util.Deque;
public class TapTempo {
 static double computeBPM(long currentTime, long lastTime, int occurenceCount) {
 if (occurenceCount == 0) {
 occurenceCount = 1;
 }
 double elapsedTime = currentTime - lastTime;
 double meanTime = elapsedTime / occurenceCount;
 double bpm = 60.0 * 1000 / meanTime;
 return bpm;
 }
 public static void main(String[] args) throws Exception {
 int precision = 0;
 int resetTime = 5;
 int sampleSize = 5;
 Options options = new Options();
 Deque<Long> hitTimePoints = new ArrayDeque<Long>();;
 Option optHelp = new Option("h", "help", false, "Display this help message.");
 optHelp.setRequired(false);
 options.addOption(optHelp);
 Option optPrecision = new Option("p", "precision", true, "Set the decimal precision of the tempo display. Default is 0 digits, max is 5 digits.");
 optPrecision.setRequired(false);
 options.addOption(optPrecision);
 Option optResetTime = new Option("r", "reset-time", true, "Set the time in second to reset the computation. Default is 5 seconds.");
 optResetTime.setRequired(false);
 options.addOption(optResetTime);
 Option optSampleSize = new Option("s", "sample-size", true, "Set the number of samples needed to compute the tempo. Default is 5 samples.");
 optSampleSize.setRequired(false);
 options.addOption(optSampleSize);
 Option optVersion = new Option("v", "version", false, "Display the version.");
 optVersion.setRequired(false);
 options.addOption(optVersion);
 CommandLineParser parser = new DefaultParser();
 HelpFormatter formatter = new HelpFormatter();
 CommandLine cmd = null;
 try {
 cmd = parser.parse(options, args);
 if (cmd.hasOption('p')) {
 precision = Integer.parseInt(cmd.getOptionValue('p'));
 if (precision < 0) {
 precision = 0;
 } else if (precision > 5) {
 precision = 5;
 }
 }
 if (cmd.hasOption('r')) {
 resetTime = Integer.parseInt(cmd.getOptionValue('r'));
 if (resetTime < 1) {
 resetTime = 1;
 }
 }
 if (cmd.hasOption('s')) {
 sampleSize = Integer.parseInt(cmd.getOptionValue('s'));
 if (sampleSize < 1) {
 sampleSize = 1;
 }
 }
 } catch (ParseException|NumberFormatException e) {
 System.out.println(e.getClass() + ": "+ e.getMessage());
 formatter.printHelp("TempoTap", options);
 System.exit(1);
 }
 if (cmd.hasOption('h') || cmd.hasOption('v')) {
 if (cmd.hasOption('h')) {
 formatter.printHelp("TempoTap", options);
 }
 if (cmd.hasOption('v')) {
 System.out.println("Version: 1.0");
 }
 System.exit(0);
 }
 DecimalFormat df = new DecimalFormat();
 df.setMaximumFractionDigits(precision);
 df.setMinimumFractionDigits(precision);
 System.out.println("Hit enter key for each beat (q to quit).\n"); 
 Scanner keyboard = new Scanner(System.in);
 keyboard.useDelimiter("");
 boolean shouldContinue = true;
 while (shouldContinue) {
 char c;
 do {
 c = keyboard.next().charAt(0);
 if (c == 'q') {
 shouldContinue = false;
 System.out.println("Bye Bye!\n");
 break;
 }
 } while (c != 10);
 if(shouldContinue) {
 long currentTime = System.currentTimeMillis();
 // Reset if the hit diff is too big.
 if (!hitTimePoints.isEmpty() && currentTime - hitTimePoints.getLast() > resetTime * 1000) {
 // Clear the history.
 hitTimePoints.clear();
 }
 hitTimePoints.add(currentTime);
 if (hitTimePoints.size() > 1) {
 double bpm = computeBPM(hitTimePoints.getLast(), hitTimePoints.getFirst(), hitTimePoints.size() - 1);
 String bpmRepresentation = df.format(bpm);
 System.out.println("Tempo: " + bpmRepresentation + " bpm");
 } else {
 System.out.println("[Hit enter key one more time to start bpm computation...]");
 }
 while (hitTimePoints.size() > sampleSize) {
 hitTimePoints.pop();
 }
 }
 }
 }
}