implemented checkArguments to prohibit crash on

missing required arguments

src/main/java/de/b00tload/tools/lastfmtospotifyplaylist/LastFMToSpotify.java

@@ -22,6 +22,10 @@ public class LastFMToSpotify {
         // create hash map with user agent
         configuration = new HashMap<>();
         configuration.put("requests.useragent", "LastFMToSpotify/1.0-Snapshot (" + System.getProperty("os.name") + "; " + System.getProperty("os.arch") + ") Java/" + System.getProperty("java.version"));
+        configuration.put("log.level", "1");
+        if (!ArgumentHandler.checkArguments(args)) {
+            return;
+        }
         // parse arguments
         for (int a = 0; a < args.length; a++) {
             Arguments arg;

src/main/java/de/b00tload/tools/lastfmtospotifyplaylist/arguments/ArgumentHandler.java

@@ -6,6 +6,10 @@ import org.jetbrains.annotations.Nullable;
 import static de.b00tload.tools.lastfmtospotifyplaylist.LastFMToSpotify.LINE_SEPERATOR;
 import static de.b00tload.tools.lastfmtospotifyplaylist.LastFMToSpotify.configuration;
 
+import java.util.List;
+
+import javax.xml.crypto.Data;
+
 public class ArgumentHandler {
 
     public static void handle(Arguments argument, @Nullable String value) {
@@ -28,6 +32,27 @@ public class ArgumentHandler {
         handle(argument, null);
     }
 
+    public static boolean checkArguments(String[] args) {
+        // check if all required arguments are given
+        Arguments[] required = {Arguments.SECRET, Arguments.CLIENT, Arguments.TOKEN, Arguments.USER};
+        for (Arguments argument : required) {
+            boolean found = false;
+            // check all aliases
+            for (String alias : argument.getAliases()) {
+                // if one alias is found check next argument
+                if (List.of(args).contains(alias)) {
+                    found = true;
+                    break;
+                }
+            }
+            // else return false
+            if (!found) {
+                return false;
+            }
+        } 
+        return true;
+    }
+
     private static void help(String value) {
         if (value == null) {
             System.out.println("This is a list of all available commands. For more specific help on the argument run --help <argument>.");