Merge branch 'modularize' into master

This branch introduces some configuration that enables Java 9 modules in this project,
adds a GPL copyright disclaimer to the output of --version flag
and makes changes to gradle that make the application version dynamically assigned using git
information and the "git describe" command.

Closes #16

build.gradle.kts

@@ -6,8 +6,17 @@ plugins {
     id("com.github.johnrengelman.shadow") version "latest.release"
 }
 
+fun versionBanner(): String {
+    val os = org.apache.commons.io.output.ByteArrayOutputStream()
+    project.exec {
+        commandLine = "git describe --always --dirty".split(" ")
+        standardOutput = os
+    }
+    return String(os.toByteArray()).trim()
+}
+
 group = "de.jotoho"
-version = "0.1.1"
+version = versionBanner()
 
 repositories {
     // Use Maven Central for resolving dependencies.
@@ -22,9 +31,10 @@ java {
 tasks.jar {
     manifest {
         attributes(
-            "Implementation-Title" to "de.jotoho.waituntil",
+            "Implementation-Title" to project.name,
-            "Implementation-Version" to "${project.version}",
+            "Implementation-Version" to project.version,
-            "Main-Class" to "de.jotoho.waituntil.Main"
+            "Main-Class" to "de.jotoho.waituntil.Main",
+            "Main-Module" to "de.jotoho.waituntil.main"
         )
     }
 }
@@ -32,4 +42,5 @@ tasks.jar {
 application {
     // Define the main class for the application.
     mainClass.set("de.jotoho.waituntil.Main")
+    mainModule.set("de.jotoho.waituntil.main")
 }

settings.gradle.kts

@@ -7,4 +7,4 @@
  * in the user manual at https://docs.gradle.org/7.2/userguide/multi_project_builds.html
  */
 
-rootProject.name = "de.jotoho.waituntil"
+rootProject.name = "waituntil"

src/main/java/de/jotoho/waituntil/Main.java

@@ -1,6 +1,7 @@
 package de.jotoho.waituntil;
 
-import java.util.*;
+import java.util.HashSet;
+import java.util.Map;
 
 import static de.jotoho.waituntil.GlobalConf.applicationOutputLanguage;
 
@@ -35,8 +36,19 @@ public final class Main {
             }
         } else if (options.contains("version")) {
             final var thisPackage = Main.class.getPackage();
-            final var appVersion = thisPackage.getImplementationVersion() != null ? thisPackage.getImplementationVersion() :"UNKNOWN";
+            final var appVersion = thisPackage.getImplementationVersion() != null
-            System.out.println("de.jotoho.waituntil version " + appVersion);
+                    ? thisPackage.getImplementationVersion()
+                    : "version unknown";
+            System.out.println("waituntil " + appVersion);
+            System.out.println("""
+
+                    This program is free software: you can redistribute it and/or modify it under the terms of the
+                    GNU General Public License as published by the Free Software Foundation, either version 3 of the
+                    License, or (at your option) any later version.
+
+                    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+                    without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+                    See the GNU General Public License for more details.""");
         } else if (words.size() == 1) {
             final var target = TimeCalculator.calculateAndAnnounceTargetTime(words.iterator().next());
             Sleep.waitUntilTimeStamp(target);

src/main/java/module-info.java

@@ -0,0 +1,2 @@
+module de.jotoho.waituntil.main {
+}