updated license information

.idea/modules.xml

@@ -3,7 +3,7 @@
   <component name="ProjectModuleManager">
     <modules>
       <module fileurl="file://$PROJECT_DIR$/GgtUndKgv/GgtUndKgv.iml" filepath="$PROJECT_DIR$/GgtUndKgv/GgtUndKgv.iml" />
-      <module fileurl="file://$PROJECT_DIR$/GreogorianischerKalender/GreogorianischerKalender.iml" filepath="$PROJECT_DIR$/GreogorianischerKalender/GreogorianischerKalender.iml" />
+      <module fileurl="file://$PROJECT_DIR$/GregorianischerKalender/GregorianischerKalender.iml" filepath="$PROJECT_DIR$/GregorianischerKalender/GregorianischerKalender.iml" />
       <module fileurl="file://$PROJECT_DIR$/.idea/Java-Programming.iml" filepath="$PROJECT_DIR$/.idea/Java-Programming.iml" />
       <module fileurl="file://$PROJECT_DIR$/Konto/Konto.iml" filepath="$PROJECT_DIR$/Konto/Konto.iml" />
       <module fileurl="file://$PROJECT_DIR$/Maximum/Maximum.iml" filepath="$PROJECT_DIR$/Maximum/Maximum.iml" />

GgtUndKgv/src/Main.java

@@ -1,18 +1,58 @@
 import javax.swing.*;
 
+/**
+ * Generic test class for implementing
+ * ggt and kgv
+ *                _ _   _               _
+ * __      ___ __(_) |_| |_ ___ _ __   | |__  _   _
+ * \ \ /\ / / '__| | __| __/ _ \ '_ \  | '_ \| | | |
+ *  \ V  V /| |  | | |_| ||  __/ | | | | |_) | |_| |
+ *   \_/\_/ |_|  |_|\__|\__\___|_| |_| |_.__/ \__, |
+ *                                            |___/
+ *  ____                  __     __               _
+ * / ___|_   _____ _ __   \ \   / /__   __ _  ___| |
+ * \___ \ \ / / _ \ '_ \   \ \ / / _ \ / _` |/ _ \ |
+ *  ___) \ V /  __/ | | |   \ V / (_) | (_| |  __/ |
+ * |____/ \_/ \___|_| |_|    \_/ \___/ \__, |\___|_|
+ *                                     |___/
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ */
 class Rechnen {
-    static int ggt(int x, int y) {
+    /**
+     * compute the greatest common divisor of x and y
+     * @param x the first number to compute the greatest common divisor of
+     * @param y the second number to compute the greatest common divisor of
+     * @return the greatest common divisor of x and y
+     */
+    public static int ggt(int x, int y) {
         if (x == 0)
             return y;
 
         return ggt(x, y % x);
     }
 
-    static int kgv(int x, int y) {
+    /**
+     * compute the smallest common multiple of x and y
+     * @param x the first number to compute the smallest common multiple of
+     * @param y the second number to compute the smallest common multiple of
+     * @return the smallest common multiple of x and y
+     */
+    public static int kgv(int x, int y) {
         return (x * y) / ggt(x, y);
     }
 }
 
+/**
+ * Generic test class for testing
+ * kgv and ggt
+ * <p>
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ * <p>
+ * NOTE: following code mostly copied from the teacher,
+ * expect no comments or functionality
+ */
 public class Main {
 
     public static void main(String[] args) {

GregorianischerKalender/src/Main.java

@@ -0,0 +1,38 @@
+/**
+ * Generic test class for implementing and testing
+ * for leap years according to the gregorian calendar
+ *                _ _   _               _
+ * __      ___ __(_) |_| |_ ___ _ __   | |__  _   _
+ * \ \ /\ / / '__| | __| __/ _ \ '_ \  | '_ \| | | |
+ *  \ V  V /| |  | | |_| ||  __/ | | | | |_) | |_| |
+ *   \_/\_/ |_|  |_|\__|\__\___|_| |_| |_.__/ \__, |
+ *                                            |___/
+ *  ____                  __     __               _
+ * / ___|_   _____ _ __   \ \   / /__   __ _  ___| |
+ * \___ \ \ / / _ \ '_ \   \ \ / / _ \ / _` |/ _ \ |
+ *  ___) \ V /  __/ | | |   \ V / (_) | (_| |  __/ |
+ * |____/ \_/ \___|_| |_|    \_/ \___/ \__, |\___|_|
+ *                                     |___/
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ */
+public class Main {
+
+    /**
+     * Test whether the supplied year is a leap year according to the gregorian calendar
+     * @apiNote also works with negative numbers
+     * @param year the year to test
+     * @return if the year is a leap year
+     */
+    private static boolean isLeapYearGregorianCalendar(int year) {
+        int decade = year / 10;
+        return decade % 4 != 0;
+    }
+
+    public static void main(String[] args) {
+        System.out.println("is leap year: 1904: " + isLeapYearGregorianCalendar(1904));
+        System.out.println("is leap year: 1003: " + isLeapYearGregorianCalendar(1003));
+        System.out.println("is leap year: 1422: " + isLeapYearGregorianCalendar(1422));
+        System.out.println("is leap year: 2022: " + isLeapYearGregorianCalendar(2022));
+    }
+}

GreogorianischerKalender/src/Main.java

@@ -1,14 +0,0 @@
-public class Main {
-
-    private static boolean isLeapYearGregorianCalendar(int year) {
-        int decade = year / 10;
-        return decade % 4 != 0;
-    }
-
-    public static void main(String[] args) {
-        System.out.println("is leap year: 1904: " + isLeapYearGregorianCalendar(1904));
-        System.out.println("is leap year: 1003: " + isLeapYearGregorianCalendar(1003));
-        System.out.println("is leap year: 1422: " + isLeapYearGregorianCalendar(1422));
-        System.out.println("is leap year: 2022: " + isLeapYearGregorianCalendar(2022));
-    }
-}

Konto/src/Konto.java

@@ -1,8 +1,33 @@
+/**
+ * Generic test class for implementing and testing
+ * a basic Konto
+ *                _ _   _               _
+ * __      ___ __(_) |_| |_ ___ _ __   | |__  _   _
+ * \ \ /\ / / '__| | __| __/ _ \ '_ \  | '_ \| | | |
+ *  \ V  V /| |  | | |_| ||  __/ | | | | |_) | |_| |
+ *   \_/\_/ |_|  |_|\__|\__\___|_| |_| |_.__/ \__, |
+ *                                            |___/
+ *  ____                  __     __               _
+ * / ___|_   _____ _ __   \ \   / /__   __ _  ___| |
+ * \___ \ \ / / _ \ '_ \   \ \ / / _ \ / _` |/ _ \ |
+ *  ___) \ V /  __/ | | |   \ V / (_) | (_| |  __/ |
+ * |____/ \_/ \___|_| |_|    \_/ \___/ \__, |\___|_|
+ *                                     |___/
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ */
 public class Konto {
 
     private double guthaben;
 
-    void abheben(double betrag) {
+    /**
+     * Get some money from the konto.
+     * If the betrag is less than the money contained by the konto,
+     * then the maximum possible amount is taken from the konto and a message is printed
+     * to System.out
+     * @param betrag the amount of money to get out of the konto
+     */
+    public void abheben(double betrag) {
         var neuesGuthaben = guthaben - betrag;
         if (neuesGuthaben < 0) {
             System.out.println("Sie konnten nur " + guthaben + " abheben");
@@ -12,15 +37,23 @@ public class Konto {
         guthaben = neuesGuthaben;
     }
 
-    void einzahlen(double betrag) {
+    /**
+     * Put some money in the konto.
+     * @exception IllegalArgumentException When betrag is negative
+     * @param betrag the amount of money to add to the konto
+     */
+    public void einzahlen(double betrag) {
         if (betrag < 0) {
-            System.err.println("no");
+            throw new IllegalArgumentException("Man kann keinen negativen Betrag einzahlen");
-            return;
         }
         this.guthaben += betrag;
     }
 
-    double getGuthaben() {
+    /**
+     * Get the amount of memory in the konto
+     * @return the amount of memory in the konto
+     */
+    public double getGuthaben() {
         return guthaben;
     }
 
@@ -29,7 +62,7 @@ public class Konto {
 
         konto.einzahlen(134);
         konto.einzahlen(0.345);
-        System.out.println("guthaben: " + konto.getGuthaben());
+        System.out.println("Guthaben: " + konto.getGuthaben());
         konto.abheben(1e6);
     }
 }

Maximum/src/Main.java

@@ -1,19 +1,58 @@
+/**
+ * Generic test class for implementing and testing
+ * custom minimum and maximum methods
+ *                _ _   _               _
+ * __      ___ __(_) |_| |_ ___ _ __   | |__  _   _
+ * \ \ /\ / / '__| | __| __/ _ \ '_ \  | '_ \| | | |
+ *  \ V  V /| |  | | |_| ||  __/ | | | | |_) | |_| |
+ *   \_/\_/ |_|  |_|\__|\__\___|_| |_| |_.__/ \__, |
+ *                                            |___/
+ *  ____                  __     __               _
+ * / ___|_   _____ _ __   \ \   / /__   __ _  ___| |
+ * \___ \ \ / / _ \ '_ \   \ \ / / _ \ / _` |/ _ \ |
+ *  ___) \ V /  __/ | | |   \ V / (_) | (_| |  __/ |
+ * |____/ \_/ \___|_| |_|    \_/ \___/ \__, |\___|_|
+ *                                     |___/
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ */
 public class Main {
 
-    static int max(int a, int b) {
+    /**
+     * compute the maximum of a and b
+     * @apiNote prints the result ot System.out
+     * @param a the first value to compute the maximum of
+     * @param b the second value to compute the maximum of
+     * @return the maximum of the two values
+     */
+    private static int max(int a, int b) {
         int max = a > b ? a : b;
         System.out.println("max: " + max);
         return max;
     }
 
-    static int max(int a, int b, int c) {
+    /**
+     * Compute the maximum of a and b
+     * @param a the first value to compute the maximum of
+     * @param b the second value to compute the maximum of
+     * @param c the third value to compute the maximum of
+     * @return the maximum of the values
+     */
+    private static int max(int a, int b, int c) {
         if (a < b) {
             return b > c ? c : a;
         }
         return a > c ? a : c;
     }
 
-    static double max(double a, double b, double c) {
+    /**
+     * Compute the minimum of a and b
+     * @param a the first value to compute the minimum of
+     * @param b the second value to compute the minimum of
+     * @param c the third value to compute the minimum of
+     * @return the minimum of the values
+     */
+    private static double max(double a, double b, double c) {
         if (a < b) {
             return b > c ? c : a;
         }

README.md

@@ -1,2 +1,8 @@
 # Java-Programming
+This repository contains most of the exercises from the Java course at the DHBW.
 
+Most of the projects found in this repository must be compiled with at least Java version 11, due to features
+being used such as the `var` keyword or pattern matching.
+No projects utilize external dependencies not supplied by at least the Adopt OpenJDK.
+The IDE used to write, test and execute the projects was Intellij-IDEA.
+Therefore the projects have no direct compatibility with Eclipse.

Verzinsung/src/Main.java

@@ -1,10 +1,39 @@
 import javax.swing.*;
 
+/**
+ * Generic test class for implementing and testing
+ * custom minimum and maximum methods
+ *                _ _   _               _
+ * __      ___ __(_) |_| |_ ___ _ __   | |__  _   _
+ * \ \ /\ / / '__| | __| __/ _ \ '_ \  | '_ \| | | |
+ *  \ V  V /| |  | | |_| ||  __/ | | | | |_) | |_| |
+ *   \_/\_/ |_|  |_|\__|\__\___|_| |_| |_.__/ \__, |
+ *                                            |___/
+ *  ____                  __     __               _
+ * / ___|_   _____ _ __   \ \   / /__   __ _  ___| |
+ * \___ \ \ / / _ \ '_ \   \ \ / / _ \ / _` |/ _ \ |
+ *  ___) \ V /  __/ | | |   \ V / (_) | (_| |  __/ |
+ * |____/ \_/ \___|_| |_|    \_/ \___/ \__, |\___|_|
+ *                                     |___/
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ */
 public class Main {
 
-    static double linearZins(double kp, double zs, int n) {
+    /**
+     * calculate the linear zins over a span of years
+     * @param kp kaptial to invest at the beginning
+     * @param zs zinssatz or the amount of increase in normalized percentage [0; 1]
+     * @param n number of years to calculate
+     * @return the total amount of money
+     */
+    private static double linearZins(double kp, double zs, int n) {
         double k = kp;
 
+        if (n < 0) {
+            throw new IllegalArgumentException("years must not be negative");
+        }
+
         for (int i = 0; i < n; i++) {
             k += kp * zs;
         }
@@ -12,9 +41,20 @@ public class Main {
         return k;
     }
 
+    /**
+     * calculate the exponetial zins over a span of years
+     * @param kp kaptial to invest at the beginning
+     * @param zs zinssatz or the amount of increase in normalized percentage [0; 1]
+     * @param n number of years to calculate
+     * @return the total amount of money
+     */
     static double expZins(double kp, double zs, int n) {
         double k = kp;
 
+        if (n < 0) {
+            throw new IllegalArgumentException("years must not be negative");
+        }
+
         for (int i = 0; i < n; i++) {
             k += k * zs;
         }
@@ -22,6 +62,13 @@ public class Main {
         return k;
     }
 
+    /**
+     * Opens system dialog requesting the user to enter a string.
+     * Ths string gets converted to a double and tested for its sign.
+     * If the input is invalid, i.e. not a unsigned rational number, the popup will appear again.
+     * @param message the message to be displayed
+     * @return the user input
+     */
     static double enterUnsigendDouble(String message) {
         while (true) {
             try {

Zaubern/src/Main.java

@@ -1,5 +1,26 @@
 import java.util.Random;
 
+/**
+ * Generic test class for implementing and testing
+ * custom minimum and maximum methods
+ *                _ _   _               _
+ * __      ___ __(_) |_| |_ ___ _ __   | |__  _   _
+ * \ \ /\ / / '__| | __| __/ _ \ '_ \  | '_ \| | | |
+ *  \ V  V /| |  | | |_| ||  __/ | | | | |_) | |_| |
+ *   \_/\_/ |_|  |_|\__|\__\___|_| |_| |_.__/ \__, |
+ *                                            |___/
+ *  ____                  __     __               _
+ * / ___|_   _____ _ __   \ \   / /__   __ _  ___| |
+ * \___ \ \ / / _ \ '_ \   \ \ / / _ \ / _` |/ _ \ |
+ *  ___) \ V /  __/ | | |   \ V / (_) | (_| |  __/ |
+ * |____/ \_/ \___|_| |_|    \_/ \___/ \__, |\___|_|
+ *                                     |___/
+ * Licensed under the GPLv2 License, Version 2.0 (the "License");
+ * Copyright (c) Sven Vogel
+ *
+ * NOTE: following code mostly copied from the teacher,
+ * expect no comments or functionality
+ */
 public class Main {
 
     enum Zauberspruch {