enabled easier/ custom creation of loggers

to all of the ones of the java.util.logging.Logger by extending from it

Darlehenberechner.java

@@ -69,6 +69,12 @@ class Darlehenberechner {
       }
 
 
+      public Konfiguration setLaufzeitJahre(Integer jahre) {
+         this.laufzeitMonate = (jahre * 12);
+         return this;
+      }
+
+
       public Konfiguration setLaufzeit(Integer jahre, Integer monate) {
          this.laufzeitMonate = (jahre * 12) + monate;
          return this;
@@ -172,7 +178,7 @@ class Darlehenberechner {
    }
 
 
-   private static void askParametersAndRun() throws IOException {
+   private static void askParametersAndRun() throws ParseException, IOException {
       DECIMAL_FORMAT.setParseBigDecimal(true);
 
       var konfig = new Konfiguration();
@@ -211,7 +217,7 @@ class Darlehenberechner {
    }
 
 
-   private static void parseParametersAndRun(String[] args) {
+   private static void parseParametersAndRun(String[] args) throws ParseException {
       var konfig = new Konfiguration();
       int count = 0;
       DECIMAL_FORMAT.setParseBigDecimal(true);

DrinkingBar.java

@@ -0,0 +1,165 @@
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.math.MathContext;
+import java.math.RoundingMode;
+import java.nio.charset.StandardCharsets;
+import java.text.DecimalFormat;
+import java.time.LocalTime;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoUnit;
+import java.util.concurrent.TimeUnit;
+
+public class DrinkingBar {
+
+   private static final DateTimeFormatter TIME_FORMATTER = DateTimeFormatter.ofPattern("HH:mm");
+   private static final int MINS_PER_HOUR = 60;
+   private static final int MINS_PER_HALF_HOUR = MINS_PER_HOUR / 2;
+   private static final int MINUTES_BEFORE_PAUSE = 4 * MINS_PER_HOUR + MINS_PER_HALF_HOUR;
+   private static final int MINUTES_WITH_PAUSE = 6 * MINS_PER_HOUR;
+   private static final int DEFAULT_TOTAL_TIME = 8 * MINS_PER_HOUR + MINS_PER_HALF_HOUR;
+   private static final BigDecimal DEFAULT_TOTAL_TIME_BD = BigDecimal.valueOf(DEFAULT_TOTAL_TIME);
+   private static final BigDecimal DEFAULT_TOTAL_LITRES = BigDecimal.valueOf(2.0);
+   private static final BigDecimal QUARTER_LITRE = BigDecimal.valueOf(0.25);
+   private static final DecimalFormat LITRE_FORMAT = new DecimalFormat("0.00");
+   private static final DecimalFormat PERCENTAGE_FORMAT = new DecimalFormat("00.00");
+   private static final BigDecimal MINS_PER_HOUR_BD = BigDecimal.valueOf(MINS_PER_HOUR);
+   private static final MathContext MC_INTEGER = new MathContext(1, RoundingMode.HALF_EVEN);
+
+   private final LocalTime startTime;
+   private LocalTime endTime;
+   private long totalMinutes;
+   private BigDecimal totalMinutesBD;
+   private BigDecimal totalLitres;
+
+
+   private DrinkingBar(LocalTime startTime) {
+      this.startTime = startTime;
+      this.totalMinutes = DEFAULT_TOTAL_TIME;
+      this.totalMinutesBD = BigDecimal.valueOf(totalMinutes);
+      this.endTime = startTime.plusMinutes(totalMinutes);
+      this.totalLitres = DEFAULT_TOTAL_LITRES;
+   }
+
+
+   public static void main(String[] args) throws IOException {
+      var br = new BufferedReader(new InputStreamReader(System.in, StandardCharsets.UTF_8));
+      print("Ankunftszeit: ");
+      var startTime = LocalTime.parse(br.readLine(), TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
+      var db = new DrinkingBar(startTime);
+      db.showLoadingBar();
+   }
+
+
+   private static void println(Object o) {
+      System.out.println(o);
+   }
+
+
+   private static void print(Object o) {
+      System.out.print(o);
+   }
+
+
+   protected long getPassedMinutes() {
+      return startTime.until(LocalTime.now().truncatedTo(ChronoUnit.MINUTES), ChronoUnit.MINUTES);
+   }
+
+
+   private void setEndTime(LocalTime endTime) {
+      this.endTime = endTime;
+      this.totalMinutes = startTime.until(endTime, ChronoUnit.MINUTES);
+      this.totalMinutesBD = BigDecimal.valueOf(totalMinutes);
+      extraInitEndTimeTotalMinutes();
+   }
+
+
+   protected void extraInitEndTimeTotalMinutes() {
+      // correct necessary litres to drink based on the end time.
+      // lower the volume in quarter litre steps
+      BigDecimal calcTotalLitres = DEFAULT_TOTAL_LITRES;
+      BigDecimal totalLitresFromMinutes = DEFAULT_TOTAL_LITRES
+         .multiply(totalMinutesBD) // reverse dreisatz
+         .divide(DEFAULT_TOTAL_TIME_BD, MathContext.DECIMAL64);
+      do {
+         calcTotalLitres = calcTotalLitres.subtract(QUARTER_LITRE);
+      } while (calcTotalLitres.compareTo(totalLitresFromMinutes) >= 0);
+      // add quarter since we always did a step "too many", due to the do ... while loop
+      this.totalLitres = calcTotalLitres.add(QUARTER_LITRE);
+   }
+
+
+   private void showLoadingBar() {
+      long passedMinutes = getPassedMinutes();
+      // long passedMinutes = 0; // DEBUG
+      if (passedMinutes > totalMinutes) {
+         passedMinutes = totalMinutes;
+      } else if (passedMinutes < 0) {
+         var now = LocalTime.now().truncatedTo(ChronoUnit.SECONDS);
+         println("!ACHTUNG! Startzeit \"" + startTime + ":00\" liegt in der Zukunft von jetzt an (" + now + ") gesehen.");
+      }
+      println(minutesToTimeString(totalMinutesBD) + " gesamt; Endzeit: " + TIME_FORMATTER.format(endTime));
+      while (passedMinutes < totalMinutes) {
+         print(fillLoadingBar(passedMinutes, true));
+         waitUntilNextMinute();
+         passedMinutes++;
+      }
+      println(fillLoadingBar(passedMinutes, false));
+   }
+
+
+   private String fillLoadingBar(long passedMinutes, boolean progressive) {
+      long effectivePassedMinutes = passedMinutes < 0 ? 0 : passedMinutes;
+      if (totalMinutes > MINUTES_WITH_PAUSE && passedMinutes > MINUTES_BEFORE_PAUSE && passedMinutes <= MINUTES_WITH_PAUSE) {
+         effectivePassedMinutes = MINUTES_BEFORE_PAUSE;
+      }
+      var effectivePassedMinutesBD = BigDecimal.valueOf(effectivePassedMinutes);
+      BigDecimal currentLitres = totalLitres
+         .multiply(effectivePassedMinutesBD) // reverse dreisatz
+         .divide(totalMinutesBD, MathContext.DECIMAL64)
+         .add(QUARTER_LITRE);
+      BigDecimal printedLitres = currentLitres.subtract(currentLitres.remainder(QUARTER_LITRE, MathContext.DECIMAL64));
+      /* BigDecimal currentProgressToNextStep = ONE_HUNDRED_PERCENT
+         .multiply(currentLitres.subtract(printedLitres)) // reverse dreisatz
+         .divide(QUARTER_LITRE, MathContext.DECIMAL64); */
+      BigDecimal minutesToNextStep = getMinutesToNextStep(currentLitres);
+      String progressivePart = progressive ? "\r" : "";
+      return progressivePart + "Aktuelles Volumen: " + LITRE_FORMAT.format(printedLitres) + "L - "
+         // + PERCENTAGE_FORMAT.format(currentProgressToNextStep) + "% - "
+         + minutesToTimeString(minutesToNextStep);
+   }
+
+
+   private BigDecimal getMinutesToNextStep(BigDecimal currentLitres) {
+      // berechne Liter benötigt bis zum nächsten 0.25er Schritt
+      BigDecimal litresToNextStep = QUARTER_LITRE.subtract(currentLitres.remainder(QUARTER_LITRE));
+      // berechne Minuten benötigt für 1 Liter
+      BigDecimal minutesPerLitre = totalMinutesBD.divide(totalLitres, MathContext.DECIMAL64);
+      // berechne Minuten benötigt bis zum nächsten 0.25er Schritt
+      // runde auf ganze Zahl, da wir nur ganze Minuten anzeigen und damit 1.999 = 2 Minuten sind
+      return minutesPerLitre.multiply(litresToNextStep).setScale(0, RoundingMode.HALF_EVEN);
+   }
+
+
+   private String minutesToTimeString(BigDecimal minutes) {
+      BigDecimal[] hoursAndMinutes = minutes.divideAndRemainder(MINS_PER_HOUR_BD, MC_INTEGER);
+      return LocalTime.of(hoursAndMinutes[0].intValue(), hoursAndMinutes[1].intValue()).format(TIME_FORMATTER);
+   }
+
+
+   private void waitUntilNextMinute() {
+      try {
+         var now = LocalTime.now();
+         var oneMinuteLater = now.plusMinutes(1).truncatedTo(ChronoUnit.MINUTES);
+         /* We wait whole seconds to not make it overly complicated.
+            That results in cut milliseconds: if we would have to wait 1 second and 526 milliseconds, we wait only 1 second.
+            So, adjust for ignored milliseconds, add +1 second as it is better to switch between 00 and 01 as between 59 and 00 */
+         TimeUnit.SECONDS.sleep(now.until(oneMinuteLater, ChronoUnit.SECONDS) + 1);
+         // TimeUnit.MILLISECONDS.sleep(100L); // DEBUG
+      } catch (InterruptedException ie) {
+         Thread.currentThread().interrupt();
+         throw new RuntimeException(ie);
+      }
+   }
+}

FabianUtil.java

@@ -1,20 +1,26 @@
-package de.vorsorge.theo.util;
+package FIXME;
 
-import java.io.IOException;
+import java.io.*;
 import java.math.BigDecimal;
 import java.math.MathContext;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.text.DecimalFormat;
 import java.time.Duration;
 import java.time.ZonedDateTime;
 import java.time.temporal.ChronoUnit;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Supplier;
+import java.util.logging.Level;
 
+@SuppressWarnings("unused")
 public class FabianUtil {
 
+   private static final Logger LOG = new Logger(FabianUtil.class);
+
    private static final String STD_DIR_TEMP = "/FIXME/temp/";
+   private static final String TEST_OUTPUT_DIR = "testOutput/";
    public static final String ENDING_TXT = "txt";
    public static final String ENDING_JSON = "json";
    public static final String ENDING_HTML = "html";
@@ -25,8 +31,92 @@ public class FabianUtil {
    private FabianUtil() {}
 
 
+   public static class Logger extends java.util.logging.Logger {
+
+      public Logger(Class<?> clazz) {
+         this(java.util.logging.Logger.getLogger(clazz.getName()));
+      }
+
+
+      public Logger(java.util.logging.Logger logger) {
+         super(logger.getName(), logger.getResourceBundleName());
+      }
+
+
+      public void severe(String msg, Object param) {
+         log(Level.SEVERE, msg, param);
+      }
+
+
+      public void severe(String msg, Object... params) {
+         log(Level.SEVERE, msg, params);
+      }
+
+
+      public void warning(String msg, Object param) {
+         log(Level.WARNING, msg, param);
+      }
+
+
+      public void warning(String msg, Object... params) {
+         log(Level.WARNING, msg, params);
+      }
+
+
+      public void info(String msg, Object param) {
+         log(Level.INFO, msg, param);
+      }
+
+
+      public void info(String msg, Object... params) {
+         log(Level.INFO, msg, params);
+      }
+
+
+      public void config(String msg, Object param) {
+         log(Level.CONFIG, msg, param);
+      }
+
+
+      public void config(String msg, Object... params) {
+         log(Level.CONFIG, msg, params);
+      }
+
+
+      public void fine(String msg, Object param) {
+         log(Level.FINE, msg, param);
+      }
+
+
+      public void fine(String msg, Object... params) {
+         log(Level.FINE, msg, params);
+      }
+
+
+      public void finer(String msg, Object param) {
+         log(Level.FINER, msg, param);
+      }
+
+
+      public void finer(String msg, Object... params) {
+         log(Level.FINER, msg, params);
+      }
+
+
+      public void finest(String msg, Object param) {
+         log(Level.FINEST, msg, param);
+      }
+
+
+      public void finest(String msg, Object... params) {
+         log(Level.FINEST, msg, params);
+      }
+   }
+
+
    public static class ProgressHandler {
 
+      private static final Logger LOG = new Logger(ProgressHandler.class);
       private static final DecimalFormat TIME_DECIMAL_FORMAT = new DecimalFormat("00");
       protected static final int DEFAULT_LOG_DISTANCE = 50;
       protected static final int DEFAULT_TIME_LOG_DISTANCE = 15;
@@ -36,22 +126,29 @@ public class FabianUtil {
       private final int timeLogDistance;
       private BigDecimal counter = BigDecimal.ZERO;
       private ZonedDateTime lastLoggedAt;
+      protected final PrintStream printer;
 
 
       public ProgressHandler() {
-         this(DEFAULT_LOG_DISTANCE, DEFAULT_TIME_LOG_DISTANCE);
+         this(DEFAULT_LOG_DISTANCE, DEFAULT_TIME_LOG_DISTANCE, null);
       }
 
 
       public ProgressHandler(int logDistance) {
-         this(logDistance, DEFAULT_TIME_LOG_DISTANCE);
+         this(logDistance, DEFAULT_TIME_LOG_DISTANCE, null);
       }
 
 
       public ProgressHandler(int logDistance, int timeLogDistance) {
+         this(logDistance, timeLogDistance, null);
+      }
+
+
+      public ProgressHandler(int logDistance, int timeLogDistance, PrintStream printer) {
          startTime = ZonedDateTime.now();
          this.logDistance = validateBD(logDistance, "Log-Distanz");
          this.timeLogDistance = validateInt(timeLogDistance, "Zeitbasierte Log-Distanz");
+         this.printer = printer;
       }
 
 
@@ -68,12 +165,17 @@ public class FabianUtil {
       }
 
 
-      protected synchronized BigDecimal getCounter() {
+      protected Logger logger() {
+         return LOG;
+      }
+
+
+      protected final synchronized BigDecimal counter() {
          return counter;
       }
 
 
-      protected synchronized int getTimeLogDistance() {
+      protected final synchronized int timeLogDistance() {
          return timeLogDistance;
       }
 
@@ -103,7 +205,7 @@ public class FabianUtil {
 
 
       protected synchronized boolean shouldLog() {
-         return counter.remainder(logDistance).signum() == 0 || isBored();
+         return (printer != null || logger().isLoggable(Level.INFO)) && (counter.remainder(logDistance).signum() == 0 || isBored());
       }
 
 
@@ -120,7 +222,11 @@ public class FabianUtil {
 
       public synchronized void log() {
          Duration timePassed = getTimePassed();
-         System.out.println(counter + " Stück erledigt. " + formatDuration(timePassed) + " vergangen.");
+         if (printer != null) {
+            printer.println(counter + " Stück erledigt. " + formatDuration(timePassed) + " vergangen.");
+         } else {
+            logger().info("{} Stück erledigt. {} vergangen.", counter, formatDuration(timePassed));
+         }
          updateLastLoggedAt();
       }
 
@@ -147,44 +253,61 @@ public class FabianUtil {
 
       public synchronized void logFinal() {
          Duration timePassed = getTimePassed();
-         System.out.println(counter + " Stück (100 %) erledigt. " + formatDuration(timePassed) + " vergangen.");
+         if (printer != null) {
+            printer.println(counter + " Stück (100 %) erledigt. " + formatDuration(timePassed) + " vergangen.");
+         } else {
+            logger().info("{} Stück (100 %) erledigt. {} vergangen.", counter, formatDuration(timePassed));
+         }
       }
    }
 
 
    public static class ProgressHandlerWithTotal extends ProgressHandler {
 
+      private static final Logger LOG = new Logger(ProgressHandlerWithTotal.class);
       private static final DecimalFormat PERCENTAGE_FORMAT = new DecimalFormat("00.00");
+      private static final BigDecimal ONE_HUNDRED_PERCENT = BigDecimal.valueOf(100);
 
       private final BigDecimal total;
 
 
       public ProgressHandlerWithTotal(int total) {
-         this(DEFAULT_LOG_DISTANCE, DEFAULT_TIME_LOG_DISTANCE, total);
+         this(DEFAULT_LOG_DISTANCE, DEFAULT_TIME_LOG_DISTANCE, total, null);
       }
 
 
       public ProgressHandlerWithTotal(int logDistance, int total) {
-         this(logDistance, DEFAULT_TIME_LOG_DISTANCE, total);
+         this(logDistance, DEFAULT_TIME_LOG_DISTANCE, total, null);
       }
 
 
       public ProgressHandlerWithTotal(int logDistance, int timeLogDistance, int total) {
-         super(logDistance, timeLogDistance);
+         this(logDistance, timeLogDistance, total, null);
+      }
+
+
+      public ProgressHandlerWithTotal(int logDistance, int timeLogDistance, int total, PrintStream printer) {
+         super(logDistance, timeLogDistance, printer);
          this.total = validateBD(total, "Gesamt-Anzahl");
       }
 
 
+      @Override
+      protected Logger logger() {
+         return LOG;
+      }
+
+
       @Override
       protected synchronized boolean shouldLog() {
-         return super.shouldLog() && getCounter().compareTo(total) <= 0;
+         return super.shouldLog() && counter().compareTo(total) <= 0;
       }
 
 
       @Override
       public synchronized void log() {
-         BigDecimal counter = getCounter();
-         BigDecimal percentage = BigDecimal.valueOf(100).divide(total, MathContext.DECIMAL64).multiply(counter);
+         BigDecimal counter = counter();
+         BigDecimal percentage = ONE_HUNDRED_PERCENT.divide(total, MathContext.DECIMAL64).multiply(counter);
          Duration timePassed = getTimePassed();
 
          String remainingTimePart = "";
@@ -197,8 +320,13 @@ public class FabianUtil {
          }
 
          String counterPrint = total.compareTo(BigDecimal.TEN) >= 0 ? formatNumber(counter) : counter.toString();
-         System.out.println(counterPrint + " Stück von " + total + " (" + PERCENTAGE_FORMAT.format(percentage) + " %) erledigt. "
-             + formatDuration(timePassed) + " vergangen" + remainingTimePart + ".");
+         if (printer != null) {
+            printer.println(counterPrint + " Stück von " + total + " (" + PERCENTAGE_FORMAT.format(percentage) + " %) erledigt. "
+                + formatDuration(timePassed) + " vergangen" + remainingTimePart + ".");
+         } else {
+            logger().info("{} Stück von {} ({} %) erledigt. {} vergangen{}.",
+                counterPrint, total, PERCENTAGE_FORMAT.format(percentage), formatDuration(timePassed), remainingTimePart);
+         }
          updateLastLoggedAt();
       }
 
@@ -209,11 +337,11 @@ public class FabianUtil {
 
 
       private synchronized void logTimeBased() {
-         while (getCounter().compareTo(total) != 0) {
+         while (counter().compareTo(total) != 0) {
             logIf();
             long timeSinceLastLogged = getTimeSinceLastLogged();
             try {
-               TimeUnit.SECONDS.sleep(timeSinceLastLogged - getTimeLogDistance());
+               TimeUnit.SECONDS.sleep(timeSinceLastLogged - timeLogDistance());
             } catch (InterruptedException ie) {
                Thread.currentThread().interrupt();
                return;
@@ -224,22 +352,27 @@ public class FabianUtil {
 
 
    public static void writeTestOutput(String filename, String ending, String content) {
-      writeTestOutput(filename, ending, strToBytes(content));
-   }
-
-
-   public static byte[] strToBytes(String str) {
-      return str.getBytes(StandardCharsets.UTF_8);
+      writeToFile(STD_DIR_TEMP + TEST_OUTPUT_DIR, filename, ending, content);
    }
 
 
    public static void writeTestOutput(String filename, String ending, byte[] content) {
-      writeToFile(STD_DIR_TEMP + "testOutput/", filename, ending, content);
+      writeToFile(STD_DIR_TEMP + TEST_OUTPUT_DIR, filename, ending, content);
+   }
+
+
+   public static void writeTestOutput(String filename, String ending, InputStream content) {
+      writeToFile(STD_DIR_TEMP + TEST_OUTPUT_DIR, filename, ending, content);
+   }
+
+
+   public static void writeTestOutput(String filename, String ending, Reader content) {
+      writeToFile(STD_DIR_TEMP + TEST_OUTPUT_DIR, filename, ending, content);
    }
 
 
    public static void writeDump(String ending, String content) {
-      writeDump(ending, strToBytes(content));
+      writeToFile(STD_DIR_TEMP, "dump", ending, content);
    }
 
 
@@ -248,8 +381,18 @@ public class FabianUtil {
    }
 
 
+   public static void writeDump(String ending, InputStream content) {
+      writeToFile(STD_DIR_TEMP, "dump", ending, content);
+   }
+
+
+   public static void writeDump(String ending, Reader content) {
+      writeToFile(STD_DIR_TEMP, "dump", ending, content);
+   }
+
+
    public static void writeDump(String filename, String ending, String content) {
-      writeDump(filename, ending, strToBytes(content));
+      writeToFile(STD_DIR_TEMP, filename, ending, content);
    }
 
 
@@ -258,9 +401,45 @@ public class FabianUtil {
    }
 
 
+   public static void writeDump(String filename, String ending, InputStream content) {
+      writeToFile(STD_DIR_TEMP, filename, ending, content);
+   }
+
+
+   public static void writeDump(String filename, String ending, Reader content) {
+      writeToFile(STD_DIR_TEMP, filename, ending, content);
+   }
+
+
+   public static void writeToFile(String path, String filename, String ending, String content) {
+      writeToFile(path, filename, ending, new StringReader(content));
+   }
+
+
    public static void writeToFile(String path, String filename, String ending, byte[] content) {
-      try {
+      writeToFile(path, filename, ending, new InputStreamReader(new ByteArrayInputStream(content)));
+   }
+
+
+   public static void writeToFile(String path, String filename, String ending, InputStream content) {
+      writeToFile(path, filename, ending, new InputStreamReader(content));
+   }
+
+
+   public static void writeToFile(String path, String filename, String ending, Reader content) {
+      Path toFile = Paths.get(path + filename + "." + ending);
+      LOG.fine("Schreibe in Datei {}", toFile);
+      try (content) {
+         BufferedWriter out = Files.newBufferedWriter(toFile);
+         content.transferTo(out);
+         /* varianten: mit streams:
+         Files.copy(content, Paths.get(path + filename + "." + ending), StandardCopyOption.REPLACE_EXISTING);
+         oder selber pipen, wie beim Reader/ writer:
+         OutputStream out = Files.newOutputStream(Paths.get(path + filename + "." + ending));
+         content.transferTo(out);
+         oder mit byte-array:
          Files.write(Paths.get(path + filename + "." + ending), content);
+         */
       } catch (IOException e) {
          throw new RuntimeException(e);
       }

Java11.java

@@ -12,6 +12,8 @@ import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 class Java11 {
+
+
    public static void main(String[] args) {
       ////////
       // 1. //
@@ -159,4 +161,4 @@ interface InterfaceWithPrivateMethods {
 @Documented
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.PARAMETER)
-public @interface Nonnull {}
+@interface Nonnull {}

LoadingBar.java

@@ -27,11 +27,13 @@ public class LoadingBar {
    private static final int MIN_LUNCH_DURATION = 30;
    private static final LocalTime LATEST_LUNCH_TIME = LocalTime.of(13, 30);
    private static final int MINS_PER_HOUR = 60;
+   private static final BigDecimal MINS_PER_HOUR_BD = BigDecimal.valueOf(MINS_PER_HOUR);
    private static final long DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH = 5L * MINS_PER_HOUR;
    private static final int MAX_NUMBER_WORK_MINS_WITHOUT_LUNCH = 6 * MINS_PER_HOUR;
    private static final long MAX_NUMBER_WORK_MINS = 8L * MINS_PER_HOUR;
    private static final int LINE_LENGTH = 100;
    private static final MathContext MC_INTEGER = new MathContext(1, RoundingMode.HALF_EVEN);
+   private static final BigDecimal ONE_HUNDRED_PERCENT = BigDecimal.valueOf(100);
 
 
    private enum DaySection {
@@ -64,6 +66,17 @@ public class LoadingBar {
    }
 
 
+   private final LocalTime startTime;
+   private LocalTime endTime;
+   private long totalMinutes;
+   private BigDecimal totalMinutesBD;
+
+
+   private LoadingBar(LocalTime startTime) {
+      this.startTime = startTime;
+   }
+
+
    public static void main(String[] args) throws IOException {
       if (args.length == 0) {
          askParametersAndRun();
@@ -75,138 +88,160 @@ public class LoadingBar {
 
    private static void askParametersAndRun() throws IOException {
       var br = new BufferedReader(new InputStreamReader(System.in, StandardCharsets.UTF_8));
-      System.out.print("Ankunftszeit: ");
-      String startTimeRaw = br.readLine();
-      var startTime = LocalTime.parse(startTimeRaw, TIME_FORMATTER);
-      handleMittagspause(br, startTime);
-      handleZapfenstreich(br, startTime);
+      print("Ankunftszeit: ");
+      var startTime = LocalTime.parse(br.readLine(), TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
+      var lb = new LoadingBar(startTime);
+      if (lb.hasMittagspauseArrived()) {
+         handleMittagspause(br, lb);
+         lb.showLoadingBar();
+      }
+      handleZapfenstreich(br, lb);
+      lb.showLoadingBar();
    }
 
 
+   private static void println(Object o) {
+      System.out.println(o);
+   }
 
-   private static void handleMittagspause(BufferedReader br, LocalTime startTime) throws IOException {
-      System.out.print("Mittagspause verschieben um (optional): ");
+
+   private static void print(Object o) {
+      System.out.print(o);
+   }
+
+
+   private static void handleMittagspause(BufferedReader br, LoadingBar lb) throws IOException {
+      print("Mittagspause verschieben um (optional): ");
       String mittagspauseOffsetRaw = br.readLine();
       if (mittagspauseOffsetRaw != null && !mittagspauseOffsetRaw.isBlank()) {
          var mittagspauseOffset = Integer.parseInt(mittagspauseOffsetRaw);
-         showLoadingBarMittagspause(startTime, mittagspauseOffset);
+         lb.initMittagspause(mittagspauseOffset);
          return;
       }
-      System.out.print("Mittagspause um (optional): ");
+      print("Mittagspause um (optional): ");
       String manualMittagspauseRaw = br.readLine();
-      if (mittagspauseOffsetRaw != null && !mittagspauseOffsetRaw.isBlank()) {
-         var manualMittagspause = LocalTime.parse(manualMittagspauseRaw, TIME_FORMATTER);
-         showLoadingBarMittagspause(startTime, manualMittagspause);
+      if (manualMittagspauseRaw != null && !manualMittagspauseRaw.isBlank()) {
+         var manualMittagspause = LocalTime.parse(manualMittagspauseRaw, TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
+         lb.initMittagspause(manualMittagspause);
       } else {
-         showLoadingBarMittagspause(startTime);
+         lb.initMittagspause();
       }
    }
 
 
-   private static void handleZapfenstreich(BufferedReader br, LocalTime startTime) throws IOException {
-      System.out.print("Mittagspause hat gedauert (optional): ");
+   private static void handleZapfenstreich(BufferedReader br, LoadingBar lb) throws IOException {
+      print("Mittagspause hat gedauert (optional): ");
       String mittagspauseDurationRaw = br.readLine();
       Integer mittagspauseDuration = null;
       if (mittagspauseDurationRaw != null && !mittagspauseDurationRaw.isBlank()) {
          mittagspauseDuration = Integer.valueOf(mittagspauseDurationRaw);
       }
-      System.out.print("Feierabend verschieben um (optional): ");
+      LocalTime vorlaeufigeEndzeit = lb.startTime.plusMinutes(MAX_NUMBER_WORK_MINS)
+         .plusMinutes(mittagspauseDuration != null ? mittagspauseDuration : MIN_LUNCH_DURATION);
+      println("Endzeit: " + TIME_FORMATTER.format(vorlaeufigeEndzeit));
+      print("Feierabend verschieben um (optional): ");
       String zapfenstreichOffsetRaw = br.readLine();
       Integer zapfenstreichOffset = null;
       if (zapfenstreichOffsetRaw != null && !zapfenstreichOffsetRaw.isBlank()) {
          zapfenstreichOffset = Integer.valueOf(zapfenstreichOffsetRaw);
-         showLoadingBarZapfenstreich(startTime, mittagspauseDuration, zapfenstreichOffset);
+         lb.initZapfenstreich(mittagspauseDuration, zapfenstreichOffset);
          return;
       }
-      System.out.print("Manuelle Uhrzeit Feierabend (optional): ");
+      print("Manuelle Uhrzeit Feierabend (optional): ");
       String manualZapfenstreichRaw = br.readLine();
       LocalTime manualZapfenstreich = null;
       if (manualZapfenstreichRaw != null && !manualZapfenstreichRaw.isBlank()) {
-         manualZapfenstreich = LocalTime.parse(manualZapfenstreichRaw, TIME_FORMATTER);
-         showLoadingBarZapfenstreich(startTime, mittagspauseDuration, manualZapfenstreich);
-         return;
+         manualZapfenstreich = LocalTime.parse(manualZapfenstreichRaw, TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
+         lb.initZapfenstreich(mittagspauseDuration, manualZapfenstreich);
+      } else {
+         lb.initZapfenstreich(mittagspauseDuration);
       }
-      showLoadingBarZapfenstreich(startTime, mittagspauseDuration);
    }
 
 
    private static void parseParametersAndRun(String[] args) {
+      LoadingBar lb = getLoadingBarFromCLI(args);
+      lb.showLoadingBar();
+   }
+
+
+   private static LoadingBar getLoadingBarFromCLI(String[] args) {
       String nextArg = args[0];
       if ("--help".equals(nextArg)) {
          printHelp();
-         return;
+         System.exit(1);
       }
       verifyMinimumNumberOfArgs(args);
       verifyTimeFormat(nextArg, "Erstes Argument");
-      var startTime = LocalTime.parse(nextArg, TIME_FORMATTER);
+      var startTime = LocalTime.parse(nextArg, TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
       nextArg = args[1];
       var section = DaySection.byParam(nextArg);
       verifyDaySection(section, nextArg);
-      if (section == DaySection.MITTAG) {
-         handleMittagspause(args, startTime);
-      } else {
-         handleZapfenstreich(args, startTime);
-      }
+      return section == DaySection.MITTAG ? getLoadingBarMittagspause(args, startTime) : getLoadingBarZapfenstreich(args, startTime);
    }
 
 
-   private static void handleMittagspause(String[] args, LocalTime startTime) {
+   private static LoadingBar getLoadingBarMittagspause(String[] args, LocalTime startTime) {
+      var lb = new LoadingBar(startTime);
       if (args.length == 2) {
-         showLoadingBarMittagspause(startTime);
-         return;
+         lb.initMittagspause();
+         return lb;
       }
       String nextArg = args[2];
       if (OFFSET_PATTERN.matcher(nextArg).matches()) {
-         showLoadingBarMittagspause(startTime, Integer.parseInt(nextArg));
-         return;
+         lb.initMittagspause(Integer.parseInt(nextArg));
+         return lb;
       }
       verifyTimeFormat(nextArg, "Argument nach " + DaySection.MITTAG.getParam());
-      var manualMittagspause = LocalTime.parse(nextArg, TIME_FORMATTER);
-      showLoadingBarMittagspause(startTime, manualMittagspause);
+      var manualMittagspause = LocalTime.parse(nextArg, TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
+      lb.initMittagspause(manualMittagspause);
+      return lb;
    }
 
 
-   private static void handleZapfenstreich(String[] args, LocalTime startTime) {
+   private static LoadingBar getLoadingBarZapfenstreich(String[] args, LocalTime startTime) {
+      var lb = new LoadingBar(startTime);
       if (args.length == 2) {
-         showLoadingBarZapfenstreich(startTime);
-         return;
+         lb.initZapfenstreich();
+         return lb;
       }
       String nextArg = args[2];
       LocalTime maxZapfenstreich = null;
       int endTimeOffset = 0;
       Integer lunchDuration = null;
       if (TIME_PATTERN.matcher(nextArg).matches()) {
-         maxZapfenstreich = LocalTime.parse(nextArg, TIME_FORMATTER);
+         maxZapfenstreich = LocalTime.parse(nextArg, TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
       } else if (OFFSET_PATTERN.matcher(nextArg).matches()) {
          endTimeOffset = Integer.parseInt(nextArg);
       } else {
-         verifyDurationFormat(nextArg, "Argument nach " + DaySection.ZAPFENSTREICH.getParam(), true); // FSFIXME erweitere Fehlermeldung
+         verifyDurationFormat(nextArg, "Argument nach " + DaySection.ZAPFENSTREICH.getParam());
          lunchDuration = Integer.parseInt(nextArg);
       }
       if (args.length == 3) {
          if (maxZapfenstreich == null && endTimeOffset == 0) {
-            showLoadingBarZapfenstreich(startTime, lunchDuration);
+            lb.initZapfenstreich(lunchDuration);
          } else if (maxZapfenstreich == null) {
-            showLoadingBarZapfenstreich(startTime, lunchDuration, endTimeOffset);
+            lb.initZapfenstreich(lunchDuration, endTimeOffset);
          } else {
-            showLoadingBarZapfenstreich(startTime, lunchDuration, maxZapfenstreich);
+            lb.initZapfenstreich(lunchDuration, maxZapfenstreich);
          }
-         return;
+         return lb;
       }
       nextArg = args[3];
       if (lunchDuration == null) {
-         System.out.println("Letztes Argument darf nur auf Mittagspausendauer folgen.");
+         println("Letztes Argument darf nur auf Mittagspausendauer folgen.");
          System.exit(1);
       }
       if (maxZapfenstreich == null && !OFFSET_PATTERN.matcher(nextArg).matches()) {
          verifyTimeFormat(nextArg, "Letztes Argument nach " + DaySection.ZAPFENSTREICH.getParam() + " und Mittagspausendauer");
-         maxZapfenstreich = LocalTime.parse(nextArg, TIME_FORMATTER);
-         showLoadingBarZapfenstreich(startTime, lunchDuration, maxZapfenstreich);
-         return;
+         maxZapfenstreich = LocalTime.parse(nextArg, TIME_FORMATTER).truncatedTo(ChronoUnit.MINUTES);
+         lb.initZapfenstreich(lunchDuration, maxZapfenstreich);
+         return lb;
       }
       verifyOffsetFormat(nextArg, "Letztes Argument nach " + DaySection.ZAPFENSTREICH.getParam() + " und Enduhrzeit");
       endTimeOffset = Integer.parseInt(nextArg);
-      showLoadingBarZapfenstreich(startTime, lunchDuration, endTimeOffset);
+      lb.initZapfenstreich(lunchDuration, endTimeOffset);
+      return lb;
    }
 
 
@@ -214,34 +249,33 @@ public class LoadingBar {
       if (args.length >= 2) {
          return;
       }
-      System.out.println("Mindestens 2 Argumente müssen gegeben sein.");
+      println("Mindestens 2 Argumente müssen gegeben sein.");
       printHelp();
       System.exit(1);
    }
 
 
    private static void verifyTimeFormat(String param, String errMsgPrefix) {
-      verifyInputFormat(TIME_PATTERN, param, errMsgPrefix, true, false);
+      verifyInputFormat(TIME_PATTERN, param, errMsgPrefix, "Uhrzeitformat (" + TIME_FORMAT + ")", false);
    }
 
 
-   private static void verifyDurationFormat(String param, String errMsgPrefix, boolean timeInputPossible) {
-      verifyInputFormat(LUNCH_DURATION_PATTERN, param, errMsgPrefix, false, timeInputPossible);
+   private static void verifyDurationFormat(String param, String errMsgPrefix) {
+      verifyInputFormat(LUNCH_DURATION_PATTERN, param, errMsgPrefix, "Minutenanzahl (ganze Zahl)", true);
    }
 
 
    private static void verifyOffsetFormat(String param, String errMsgPrefix) {
-      verifyInputFormat(OFFSET_PATTERN, param, errMsgPrefix, false, false);
+      verifyInputFormat(OFFSET_PATTERN, param, errMsgPrefix, "Minutendifferenz (ganze Zahl mit Vorzeichen)", false);
    }
 
 
-   private static void verifyInputFormat(Pattern pattern, String param, String errMsgPrefix, boolean timeInput, boolean timeInputPossible) {
+   private static void verifyInputFormat(Pattern pattern, String param, String errMsgPrefix, String firstInputPart, boolean timeInputPossible) {
       if (pattern.matcher(param).matches()) {
          return;
-      } // FSFIXME fine tune message -> HH:mm, mm, -+mm
-      var firstInputPart = timeInput ? "Uhrzeitformat (" + TIME_FORMAT + ")" : "Minutenanzahl (" + LUNCH_DURATION_PATTERN + ")";
-      var possibleTimeInputPart = !timeInput && timeInputPossible ? " oder Uhrzeitformat (" + TIME_FORMAT + ")" : "";
-      System.out.println(errMsgPrefix + " \"" + param + "\" muss " + firstInputPart + possibleTimeInputPart + " entsprechen.");
+      }
+      var possibleTimeInputPart = timeInputPossible ? " oder Uhrzeitformat (" + TIME_FORMAT + ")" : "";
+      println(errMsgPrefix + " \"" + param + "\" muss " + firstInputPart + possibleTimeInputPart + " entsprechen.");
       System.exit(1);
    }
 
@@ -253,13 +287,13 @@ public class LoadingBar {
       List<String> sectionDescs = Arrays.stream(DaySection.values()).map((DaySection ds) -> ds.getDescription() + " (" + ds.getParam() + ")")
           .collect(Collectors.toList());
       String sectionDescsJoined = String.join(" oder ", sectionDescs);
-      System.out.println("Argument nach Startzeit \"" + param + "\" muss Angabe für " + sectionDescsJoined + " sein.");
+      println("Argument nach Startzeit \"" + param + "\" muss Angabe für " + sectionDescsJoined + " sein.");
       System.exit(1);
    }
 
 
    private static void printHelp() {
-      System.out.println("Mögliche Argumente für LoadingBar:\n"
+      println("Mögliche Argumente für LoadingBar:\n"
           + "Normalfall Vormittag (Mittagspause <= " + LATEST_LUNCH_TIME + ")\n"
           + TIME_FORMAT + " " + DaySection.MITTAG.getParam() + "\n"
           + "Vormittag mit expliziter Mittagspause (<= " + LATEST_LUNCH_TIME + ")\n"
@@ -289,75 +323,97 @@ public class LoadingBar {
    }
 
 
-   private static void showLoadingBarMittagspause(LocalTime startTime) {
-      showLoadingBarMittagspause(startTime, null);
+   protected long getPassedMinutes() {
+      return startTime.until(LocalTime.now().truncatedTo(ChronoUnit.MINUTES), ChronoUnit.MINUTES);
    }
 
 
-   private static void showLoadingBarMittagspause(LocalTime startTime, int endTimeOffset) {
-      LocalTime endTime = startTime.plusMinutes(DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH + endTimeOffset);
-      LocalTime trueEndTime = endTime.isAfter(LATEST_LUNCH_TIME) ? LATEST_LUNCH_TIME : endTime;
-      showLoadingBar(startTime, trueEndTime);
+   private void setEndTime(LocalTime endTime) {
+      this.endTime = endTime;
+      this.totalMinutes = startTime.until(endTime, ChronoUnit.MINUTES);
+      this.totalMinutesBD = BigDecimal.valueOf(totalMinutes);
    }
 
 
-   private static void showLoadingBarMittagspause(LocalTime startTime, LocalTime manualEndTime) {
-      LocalTime endTime = manualEndTime != null ? manualEndTime : startTime.plusMinutes(DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH);
-      LocalTime trueEndTime = endTime.isAfter(LATEST_LUNCH_TIME) ? LATEST_LUNCH_TIME : endTime;
-      showLoadingBar(startTime, trueEndTime);
+
+   private boolean hasMittagspauseArrived() {
+      return startTime.until(LocalTime.now(), ChronoUnit.MINUTES) < DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH;
    }
 
 
-   private static void showLoadingBarZapfenstreich(LocalTime startTime) {
-      showLoadingBarZapfenstreich(startTime, -1, 0);
+   private void initMittagspause() {
+      LocalTime defaultEndTime = startTime.plusMinutes(DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH);
+      realInitMittagspause(defaultEndTime);
    }
 
 
-   private static void showLoadingBarZapfenstreich(LocalTime startTime, Integer manualLunchDuration) {
-      showLoadingBarZapfenstreich(startTime, manualLunchDuration, 0);
+   private void initMittagspause(int endTimeOffset) {
+      LocalTime offsetEndTime = startTime.plusMinutes(DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH + endTimeOffset);
+      realInitMittagspause(offsetEndTime);
    }
 
 
-   private static void showLoadingBarZapfenstreich(LocalTime startTime, Integer manualLunchDuration, int endTimeOffset) {
+   private void initMittagspause(LocalTime manualEndTime) {
+      LocalTime effectiveEndTime = manualEndTime != null ? manualEndTime : startTime.plusMinutes(DEFAULT_NUMBER_WORK_MINS_BEFORE_LUNCH);
+      realInitMittagspause(effectiveEndTime);
+   }
+
+
+   private void realInitMittagspause(LocalTime theoreticalEndTime) {
+      setEndTime(theoreticalEndTime.isAfter(LATEST_LUNCH_TIME) ? LATEST_LUNCH_TIME : theoreticalEndTime);
+   }
+
+
+   private void initZapfenstreich() {
+      LocalTime trueEndTime = startTime.plusMinutes(MAX_NUMBER_WORK_MINS + MIN_LUNCH_DURATION);
+      realInitZapfenstreich(MIN_LUNCH_DURATION, trueEndTime);
+   }
+
+
+   private void initZapfenstreich(Integer manualLunchDuration) {
+      initZapfenstreich(manualLunchDuration, 0);
+   }
+
+
+   private void initZapfenstreich(Integer manualLunchDuration, int endTimeOffset) {
       long minLunchDuration = getMinLunchDuration(endTimeOffset);
       long realLunchDuration = getRealLunchDuration(manualLunchDuration, minLunchDuration);
       LocalTime trueEndTime = startTime.plusMinutes(MAX_NUMBER_WORK_MINS + realLunchDuration + endTimeOffset);
-      realShowLoadingBarZapfenstreich(startTime, realLunchDuration, trueEndTime);
+      realInitZapfenstreich(realLunchDuration, trueEndTime);
    }
 
 
-   private static void showLoadingBarZapfenstreich(LocalTime startTime, Integer manualLunchDuration, LocalTime manualEndTime) {
+   private void initZapfenstreich(Integer manualLunchDuration, LocalTime manualEndTime) {
       LocalTime trueEndTime = manualEndTime;
-      long minLunchDuration = getMinLunchDuration(startTime, trueEndTime);
+      long minLunchDuration = getMinLunchDuration(trueEndTime);
       long realLunchDuration = getRealLunchDuration(manualLunchDuration, minLunchDuration);
       if (trueEndTime == null) {
          trueEndTime = startTime.plusMinutes(MAX_NUMBER_WORK_MINS + realLunchDuration);
       }
-      realShowLoadingBarZapfenstreich(startTime, realLunchDuration, trueEndTime);
+      realInitZapfenstreich(realLunchDuration, trueEndTime);
    }
 
 
-   private static long getMinLunchDuration(int endTimeOffset) {
+   private long getMinLunchDuration(int endTimeOffset) {
       if (endTimeOffset == 0) {
          return MIN_LUNCH_DURATION;
       }
       long totalDuration = MAX_NUMBER_WORK_MINS + endTimeOffset;
-      long effectiveLunchDuration = totalDuration - MAX_NUMBER_WORK_MINS_WITHOUT_LUNCH;
-      return getMinLunchDuration(effectiveLunchDuration);
+      return getMinLunchDuration(totalDuration);
    }
 
 
-   private static long getMinLunchDuration(LocalTime startTime, LocalTime endTime) {
-      if (endTime == null) {
+   private long getMinLunchDuration(LocalTime manualEndTime) {
+      if (manualEndTime == null) {
          return MIN_LUNCH_DURATION;
       }
-      long totalDuration = startTime.until(endTime, ChronoUnit.MINUTES);
-      int effectiveLunchDuration = ((int) totalDuration) - MAX_NUMBER_WORK_MINS_WITHOUT_LUNCH;
-      return getMinLunchDuration(effectiveLunchDuration);
+      long totalDuration = startTime.until(manualEndTime, ChronoUnit.MINUTES);
+      return getMinLunchDuration(totalDuration);
    }
 
 
-   private static long getMinLunchDuration(long effectiveLunchDuration) {
+   private long getMinLunchDuration(long precalculatedTotalDuration) {
+      long effectiveLunchDuration = precalculatedTotalDuration - MAX_NUMBER_WORK_MINS_WITHOUT_LUNCH;
       if (effectiveLunchDuration < 0) {
          effectiveLunchDuration = 0;
       }
@@ -365,52 +421,61 @@ public class LoadingBar {
    }
 
 
-   private static long getRealLunchDuration(Integer manualLunchDuration, long minLunchDuration) {
+   private long getRealLunchDuration(Integer manualLunchDuration, long minLunchDuration) {
       return manualLunchDuration != null && manualLunchDuration >= minLunchDuration ? manualLunchDuration : minLunchDuration;
    }
 
 
-   private static void realShowLoadingBarZapfenstreich(LocalTime startTime, long manualLunchDuration, LocalTime endTime) {
-      if (manualLunchDuration > 0) {
-         var totalWorkTime = LocalTime.MIDNIGHT.plusMinutes(startTime.until(endTime, ChronoUnit.MINUTES) - manualLunchDuration);
-         System.out.print("Arbeitszeit: " + TIME_FORMATTER.format(totalWorkTime) + "; ");
+   private void realInitZapfenstreich(long effectiveLunchDuration, LocalTime effectiveEndTime) {
+      if (effectiveLunchDuration > 0) {
+         var totalWorkTime = LocalTime.MIDNIGHT.plusMinutes(startTime.until(effectiveEndTime, ChronoUnit.MINUTES) - effectiveLunchDuration);
+         print("Arbeitszeit: " + TIME_FORMATTER.format(totalWorkTime) + "; ");
       }
-      showLoadingBar(startTime, endTime);
+      setEndTime(effectiveEndTime);
    }
 
 
-   private static void showLoadingBar(LocalTime startTime, LocalTime endTime) {
-      long initialMinutes = startTime.until(endTime, ChronoUnit.MINUTES);
-      System.out.print(minutesToTimeString(initialMinutes) + " gesamt; Endzeit: " + TIME_FORMATTER.format(endTime) + "\n");
-      long passedMinutes = startTime.until(LocalTime.now(), ChronoUnit.MINUTES);
-      if (passedMinutes > initialMinutes) {
-         passedMinutes = initialMinutes;
+   private void showLoadingBar() {
+      long passedMinutes = getPassedMinutes();
+      // long passedMinutes = 0; // DEBUG
+      if (passedMinutes > totalMinutes) {
+         passedMinutes = totalMinutes;
       } else if (passedMinutes < 0) {
-         System.out.println(fillLoadingBar(initialMinutes, 0, false));
-         return;
+         var now = LocalTime.now().truncatedTo(ChronoUnit.SECONDS);
+         println("!ACHTUNG! Startzeit \"" + startTime + ":00\" liegt in der Zukunft von jetzt an (" + now + ") gesehen.");
       }
-      while (passedMinutes < initialMinutes) {
-         System.out.print(fillLoadingBar(initialMinutes, passedMinutes, true));
-         try {
-            var now = LocalTime.now();
-            var oneMinuteLater = now.plusMinutes(1).truncatedTo(ChronoUnit.MINUTES);
-            // +1 second to adjust for ignored milliseconds as it is better to switch between 00 and 01 as between 59 and 00
-            TimeUnit.SECONDS.sleep(now.until(oneMinuteLater, ChronoUnit.SECONDS) + 1);
-            // TimeUnit.SECONDS.sleep(1L); // DEBUG
-         } catch (InterruptedException ie) {
-            throw new RuntimeException(ie);
-         }
+      println(minutesToTimeString(totalMinutesBD) + " gesamt; Endzeit: " + TIME_FORMATTER.format(endTime));
+      while (passedMinutes < totalMinutes) {
+         print(fillLoadingBar(passedMinutes, true));
+         waitUntilNextMinute();
          passedMinutes++;
       }
-      System.out.println(fillLoadingBar(initialMinutes, passedMinutes, false));
+      println(fillLoadingBar(passedMinutes, false));
    }
 
 
-   private static String fillLoadingBar(long initialMinutes, long passedMinutes, boolean progressive) {
-      BigDecimal wholePercentage = BigDecimal.valueOf(100)
-         .multiply(BigDecimal.valueOf(passedMinutes) // kind of reverse dreisatz to avoid to have e.g. 99.9999 instead of 100 %
-         .divide(BigDecimal.valueOf(initialMinutes), MathContext.DECIMAL64));
-      long remainingMinutes = initialMinutes - passedMinutes;
+   private void waitUntilNextMinute() {
+      try {
+         var now = LocalTime.now();
+         var oneMinuteLater = now.plusMinutes(1).truncatedTo(ChronoUnit.MINUTES);
+         /* We wait whole seconds to not make it overly complicated.
+            That results in cut milliseconds: if we would have to wait 1 second and 526 milliseconds, we wait only 1 second.
+            So, adjust for ignored milliseconds, add +1 second as it is better to switch between 00 and 01 as between 59 and 00 */
+         TimeUnit.SECONDS.sleep(now.until(oneMinuteLater, ChronoUnit.SECONDS) + 1);
+         // TimeUnit.MILLISECONDS.sleep(100L); // DEBUG
+      } catch (InterruptedException ie) {
+         Thread.currentThread().interrupt();
+         throw new RuntimeException(ie);
+      }
+   }
+
+
+   private String fillLoadingBar(long passedMinutes, boolean progressive) {
+      var nonNegativePassedMinutes = BigDecimal.valueOf(passedMinutes < 0 ? 0 : passedMinutes);
+      BigDecimal wholePercentage = ONE_HUNDRED_PERCENT
+         // kind of reverse dreisatz to avoid having e.g. 99.9999 instead of 100 %
+         .multiply(nonNegativePassedMinutes)
+         .divide(totalMinutesBD, MathContext.DECIMAL64);
       int numberOfEquals = wholePercentage.intValue();
       var sb = new StringBuilder("[");
       for (int i = 0; i < LINE_LENGTH; i++) {
@@ -420,8 +485,9 @@ public class LoadingBar {
             sb.append("-");
          }
       }
+      BigDecimal remainingMinutes = totalMinutesBD.subtract(nonNegativePassedMinutes);
       sb.append("] ").append(PERCENTAGE_FORMAT.format(wholePercentage)).append("% ")
-          .append(minutesToTimeString(passedMinutes)).append(" - ").append(minutesToTimeString(remainingMinutes));
+          .append(minutesToTimeString(nonNegativePassedMinutes)).append(" - ").append(minutesToTimeString(remainingMinutes));
       if (progressive) {
          sb.append("\r");
       }
@@ -429,9 +495,8 @@ public class LoadingBar {
    }
 
 
-   private static String minutesToTimeString(long minutes) {
-      var minutesBD = BigDecimal.valueOf(minutes);
-      BigDecimal[] hoursAndMinutes = minutesBD.divideAndRemainder(BigDecimal.valueOf(MINS_PER_HOUR), MC_INTEGER);
+   private String minutesToTimeString(BigDecimal minutes) {
+      BigDecimal[] hoursAndMinutes = minutes.divideAndRemainder(MINS_PER_HOUR_BD, MC_INTEGER);
       return LocalTime.of(hoursAndMinutes[0].intValue(), hoursAndMinutes[1].intValue()).format(TIME_FORMATTER);
    }
 }

SimpleLoadingBar.java

@@ -16,8 +16,23 @@ public class SimpleLoadingBar {
    private static final Pattern TIME_PATTERN = Pattern.compile("(?>[01]\\d|2[0-4]):[0-5]\\d");
    private static final DecimalFormat PERCENTAGE_FORMAT = new DecimalFormat("00.00");
    private static final int MINS_PER_HOUR = 60;
+   private static final BigDecimal MINS_PER_HOUR_BD = BigDecimal.valueOf(MINS_PER_HOUR);
    private static final int LINE_LENGTH = 100;
    private static final MathContext MC_INTEGER = new MathContext(1, RoundingMode.HALF_EVEN);
+   private static final BigDecimal ONE_HUNDRED_PERCENT = BigDecimal.valueOf(100);
+
+   private final String title;
+   private final LocalTime startTime;
+   private LocalTime endTime;
+   private long totalMinutes;
+   private BigDecimal totalMinutesBD;
+
+
+   private SimpleLoadingBar(LocalTime startTime, LocalTime endTime, String title) {
+      this.startTime = startTime;
+      setEndTime(endTime);
+      this.title = initTitle(title);
+   }
 
 
    public static void main(String[] args) {
@@ -27,13 +42,12 @@ public class SimpleLoadingBar {
       }
       verifyMinimumNumberOfArgs(args);
       String nextArg = args[0];
-      verifyTimeFormat(nextArg, "Erstes Argument"); // FSFIXME package
-      var firstTime = LocalTime.parse(nextArg, TIME_FORMATTER); // FSFIXME package
+      verifyTimeFormat(nextArg, "Erstes Argument");
+      var firstTime = LocalTime.parse(nextArg, TIME_FORMATTER);
       LocalTime startTime = null;
       String title = "";
       LocalTime endTime = null;
       if (args.length > 1) {
-         startTime = firstTime;
          nextArg = args[1];
          if ("-msg".equals(nextArg)) {
             title = args.length > 2 ? args[2] : title;
@@ -45,23 +59,32 @@ public class SimpleLoadingBar {
       if (endTime == null) {
          startTime = LocalTime.now();
          endTime = firstTime;
+      } else {
+         startTime = firstTime;
       }
-      String fallbackTitle = "Ende! Endzeit " + TIME_FORMATTER.format(endTime) + " erreicht.";
       if (args.length == 2 || !title.isBlank()) {
-         title = title.isBlank() ? fallbackTitle : title;
-         showLoadingBar(startTime, endTime, title);
+         new SimpleLoadingBar(startTime, endTime, title).showLoadingBar();
          return;
       }
       // if there are 3 arguments, the third will be discarded.
       boolean hasTitleArg = args.length > 3 && "-msg".equals(args[2]);
       title = hasTitleArg ? args[3] : title;
-      title = title.isBlank() ? fallbackTitle : title;
-      showLoadingBar(startTime, endTime, title);
+      new SimpleLoadingBar(startTime, endTime, title).showLoadingBar();
+   }
+
+
+   private static void println(Object o) {
+      System.out.println(o);
+   }
+
+
+   private static void print(Object o) {
+      System.out.print(o);
    }
 
 
    private static void printHelp() {
-      System.out.println("Mögliche Argumente für LoadingBar:\n"
+      println("Mögliche Argumente für LoadingBar:\n"
           + "Startzeit, Endzeit, Endnachricht (Optional)\n"
           + TIME_FORMAT + " " + TIME_FORMAT + " -msg <Nachricht>\n"
           + "Endzeit (Startzeit = jetzt), Endnachricht (Optional)\n"
@@ -74,7 +97,7 @@ public class SimpleLoadingBar {
       if (args.length >= 1) {
          return;
       }
-      System.out.println("Mindestens 1 Argument muss gegeben sein.");
+      println("Mindestens 1 Argument muss gegeben sein.");
       printHelp();
       System.exit(1);
    }
@@ -84,44 +107,57 @@ public class SimpleLoadingBar {
       if (TIME_PATTERN.matcher(param).matches()) {
          return;
       }
-      System.out.println(errMsgPrefix + " \"" + param + "\" muss Uhrzeitformat (" + TIME_FORMAT + ") entsprechen.");
+      println(errMsgPrefix + " \"" + param + "\" muss Uhrzeitformat (" + TIME_FORMAT + ") entsprechen.");
       System.exit(1);
    }
 
 
-   public static void showLoadingBar(LocalTime startTime, LocalTime endTime, String title) {
-      long initialMinutes = startTime.until(endTime, ChronoUnit.MINUTES);
-      System.out.print(minutesToTimeString(initialMinutes) + " gesamt; Endzeit: " + TIME_FORMATTER.format(endTime) + "\n");
-      long passedMinutes = startTime.until(LocalTime.now(), ChronoUnit.MINUTES);
-      if (passedMinutes > initialMinutes) {
-         passedMinutes = initialMinutes;
-      } else if (passedMinutes < 0) {
-         System.out.println(fillLoadingBar(initialMinutes, 0, false));
-         return;
-      }
-      while (passedMinutes < initialMinutes) {
-         System.out.print(fillLoadingBar(initialMinutes, passedMinutes, true));
-         try {
-            var now = LocalTime.now();
-            var oneMinuteLater = now.plusMinutes(1).truncatedTo(ChronoUnit.MINUTES);
-            // +1 second to adjust for ignored milliseconds as it is better to switch between 00 and 01 as between 59 and 00
-            TimeUnit.SECONDS.sleep(now.until(oneMinuteLater, ChronoUnit.SECONDS) + 1);
-            // TimeUnit.SECONDS.sleep(1L); // DEBUG
-         } catch (InterruptedException ie) {
-            throw new RuntimeException(ie);
-         }
-         passedMinutes++;
-      }
-      System.out.println(fillLoadingBar(initialMinutes, passedMinutes, false));
-      System.out.println(formatTitle(title));
+   protected long getPassedMinutes() {
+      return startTime.until(LocalTime.now().truncatedTo(ChronoUnit.MINUTES), ChronoUnit.MINUTES);
    }
 
 
-   private static String fillLoadingBar(long initialMinutes, long passedMinutes, boolean progressive) {
-      BigDecimal wholePercentage = BigDecimal.valueOf(100)
-         .multiply(BigDecimal.valueOf(passedMinutes) // kind of reverse dreisatz to avoid to have e.g. 99.9999 instead of 100 %
-         .divide(BigDecimal.valueOf(initialMinutes), MathContext.DECIMAL64));
-      long remainingMinutes = initialMinutes - passedMinutes;
+   private void setEndTime(LocalTime endTime) {
+      this.endTime = endTime;
+      this.totalMinutes = startTime.until(endTime, ChronoUnit.MINUTES);
+      this.totalMinutesBD = BigDecimal.valueOf(totalMinutes);
+   }
+
+
+   private String initTitle(String inputTitle) {
+      String fallbackTitle = "Ende! Endzeit " + TIME_FORMATTER.format(endTime) + " erreicht.";
+      String effectiveTitle = inputTitle == null || inputTitle.isBlank() ? fallbackTitle : inputTitle;
+      String separator = "*".repeat(effectiveTitle.length());
+      return separator + "\n" + effectiveTitle + "\n" + separator;
+   }
+
+
+   private void showLoadingBar() {
+      long passedMinutes = getPassedMinutes();
+      // long passedMinutes = 0; // DEBUG
+      if (passedMinutes > totalMinutes) {
+         passedMinutes = totalMinutes;
+      } else if (passedMinutes < 0) {
+         var now = LocalTime.now().truncatedTo(ChronoUnit.SECONDS);
+         println("!ACHTUNG! Startzeit \"" + startTime + ":00\" liegt in der Zukunft von jetzt an (" + now + ") gesehen.");
+      }
+      println(minutesToTimeString(totalMinutesBD) + " gesamt; Endzeit: " + TIME_FORMATTER.format(endTime));
+      while (passedMinutes < totalMinutes) {
+         print(fillLoadingBar(passedMinutes, true));
+         waitUntilNextMinute();
+         passedMinutes++;
+      }
+      println(fillLoadingBar(passedMinutes, false));
+      println(title);
+   }
+
+
+   private String fillLoadingBar(long passedMinutes, boolean progressive) {
+      var nonNegativePassedMinutes = BigDecimal.valueOf(passedMinutes < 0 ? 0 : passedMinutes);
+      BigDecimal wholePercentage = ONE_HUNDRED_PERCENT
+         // kind of reverse dreisatz to avoid having e.g. 99.9999 instead of 100 %
+         .multiply(nonNegativePassedMinutes)
+         .divide(totalMinutesBD, MathContext.DECIMAL64);
       int numberOfEquals = wholePercentage.intValue();
       var sb = new StringBuilder("[");
       for (int i = 0; i < LINE_LENGTH; i++) {
@@ -131,8 +167,9 @@ public class SimpleLoadingBar {
             sb.append("-");
          }
       }
+      BigDecimal remainingMinutes = totalMinutesBD.subtract(nonNegativePassedMinutes);
       sb.append("] ").append(PERCENTAGE_FORMAT.format(wholePercentage)).append("% ")
-          .append(minutesToTimeString(passedMinutes)).append(" - ").append(minutesToTimeString(remainingMinutes));
+          .append(minutesToTimeString(nonNegativePassedMinutes)).append(" - ").append(minutesToTimeString(remainingMinutes));
       if (progressive) {
          sb.append("\r");
       }
@@ -140,15 +177,24 @@ public class SimpleLoadingBar {
    }
 
 
-   private static String minutesToTimeString(long minutes) {
-      var minutesBD = BigDecimal.valueOf(minutes);
-      BigDecimal[] hoursAndMinutes = minutesBD.divideAndRemainder(BigDecimal.valueOf(MINS_PER_HOUR), MC_INTEGER);
+   private String minutesToTimeString(BigDecimal minutes) {
+      BigDecimal[] hoursAndMinutes = minutes.divideAndRemainder(MINS_PER_HOUR_BD, MC_INTEGER);
       return LocalTime.of(hoursAndMinutes[0].intValue(), hoursAndMinutes[1].intValue()).format(TIME_FORMATTER);
    }
 
 
-   private static String formatTitle(String title) {
-      String separator = "*".repeat(title.length());
-      return separator + "\n" + title + "\n" + separator;
+   private void waitUntilNextMinute() {
+      try {
+         var now = LocalTime.now();
+         var oneMinuteLater = now.plusMinutes(1).truncatedTo(ChronoUnit.MINUTES);
+         /* We wait whole seconds to not make it overly complicated.
+            That results in cut milliseconds: if we would have to wait 1 second and 526 milliseconds, we wait only 1 second.
+            So, adjust for ignored milliseconds, add +1 second as it is better to switch between 00 and 01 as between 59 and 00 */
+         TimeUnit.SECONDS.sleep(now.until(oneMinuteLater, ChronoUnit.SECONDS) + 1);
+         // TimeUnit.MILLISECONDS.sleep(100L); // DEBUG
+      } catch (InterruptedException ie) {
+         Thread.currentThread().interrupt();
+         throw new RuntimeException(ie);
+      }
    }
 }