Add: Load plugins by command line

HMCL/src/main/java/org/jackhuang/hellominecraft/launcher/Main.java

@@ -107,8 +107,22 @@ public final class Main implements Runnable {
     public static void main(String[] args) throws IOException {
         {
             PluginManager.getPlugin(DefaultPlugin.class);
-            if (IUpgrader.NOW_UPGRADER.parseArguments(getVersionNumber(), args))
+            for (String s : args)
+                if (s.startsWith("--plugin=")) {
+                    String c = s.substring("--plugin=".length());
+                    try {
+                        PluginManager.getPlugin(Class.forName(c));
+                    } catch (ClassNotFoundException ex) {
+                        System.out.println("Class: " + c + " not found, please add your plugin jar to class path.");
+                    }
+                } else if (s.startsWith("--help")) {
+                    System.out.println("HMCL command line help");
+                    System.out.println("--noupdate: this arg will prevent HMCL from initializing the newest app version in %appdata%/.hmcl");
+                    System.out.println("--plugin=<your plugin class>: this arg will allow a new plugin to be loaded, please keep your jar in system class path and this class extends IPlugin.");
                     return;
+                }
+
+            IUpgrader.NOW_UPGRADER.parseArguments(getVersionNumber(), args);
 
             System.setProperty("awt.useSystemAAFontSettings", "on");
             System.setProperty("swing.aatext", "true");

HMCL/src/main/java/org/jackhuang/hellominecraft/launcher/util/upgrade/AppDataUpgrader.java

@@ -61,7 +61,7 @@ public class AppDataUpgrader extends IUpgrader {
             String mainClass = jarFile.getManifest().getMainAttributes().getValue("Main-Class");
             if (mainClass != null) {
                 ArrayList<String> al = new ArrayList<>(Arrays.asList(args));
-                al.add("nofound");
+                al.add("--noupdate");
                 AccessController.doPrivileged((PrivilegedExceptionAction<Void>) () -> {
                     new URLClassLoader(new URL[] { jar.toURI().toURL() },
                                        URLClassLoader.getSystemClassLoader().getParent()).loadClass(mainClass)
@@ -75,8 +75,8 @@ public class AppDataUpgrader extends IUpgrader {
     }
 
     @Override
-    public boolean parseArguments(VersionNumber nowVersion, String[] args) {
+    public void parseArguments(VersionNumber nowVersion, String[] args) {
-        if (!ArrayUtils.contains(args, "nofound"))
+        if (!ArrayUtils.contains(args, "--noupdate"))
             try {
                 File f = AppDataUpgraderTask.HMCL_VER_FILE;
                 if (f.exists()) {
@@ -86,15 +86,14 @@ public class AppDataUpgrader extends IUpgrader {
                         String j = m.get("loc");
                         if (j != null) {
                             File jar = new File(j);
-                            if (jar.exists())
+                            if (jar.exists() && launchNewerVersion(args, jar))
-                                return launchNewerVersion(args, jar);
+                                System.exit(0);
                         }
                     }
                 }
             } catch (Throwable t) {
                 HMCLog.err("Failed to execute newer version application", t);
             }
-        return false;
     }
 
     @Override

HMCL/src/main/java/org/jackhuang/hellominecraft/launcher/util/upgrade/IUpgrader.java

@@ -34,11 +34,8 @@ public abstract class IUpgrader implements Consumer<SimpleEvent<VersionNumber>>
      *
      * @param nowVersion now launcher version
      * @param args       Application CommandLine Arguments
-     *
-     * @return true if it is needed to break the main thread to shutdown this
-     *         application.
      */
-    public abstract boolean parseArguments(VersionNumber nowVersion, String[] args);
+    public abstract void parseArguments(VersionNumber nowVersion, String[] args);
 
     /**
      * Just download the new app.

HMCL/src/main/java/org/jackhuang/hellominecraft/launcher/util/upgrade/NewFileUpgrader.java

@@ -35,14 +35,13 @@ import org.jackhuang.hellominecraft.util.sys.IOUtils;
 public class NewFileUpgrader extends IUpgrader {
 
     @Override
-    public boolean parseArguments(VersionNumber nowVersion, String[] args) {
+    public void parseArguments(VersionNumber nowVersion, String[] args) {
         int i = ArrayUtils.indexOf(args, "--removeOldLauncher");
         if (i != -1 && i < args.length - 1) {
             File f = new File(args[i + 1]);
             if (f.exists())
                 f.deleteOnExit();
         }
-        return false;
     }
 
     @Override