Support for Android java mods

android/src/mindustry/android/AndroidLauncher.java

@@ -7,7 +7,6 @@ import android.content.pm.*;
 import android.net.*;
 import android.os.Build.*;
 import android.os.*;
-import android.provider.Settings.*;
 import android.telephony.*;
 import arc.*;
 import arc.backend.android.*;
@@ -15,7 +14,7 @@ import arc.files.*;
 import arc.func.*;
 import arc.scene.ui.layout.*;
 import arc.util.*;
-import arc.util.serialization.*;
+import dalvik.system.*;
 import mindustry.*;
 import mindustry.game.Saves.*;
 import mindustry.io.*;
@@ -23,7 +22,6 @@ import mindustry.net.*;
 import mindustry.ui.dialogs.*;
 
 import java.io.*;
-import java.lang.System;
 import java.lang.Thread.*;
 import java.util.*;
 
@@ -73,12 +71,25 @@ public class AndroidLauncher extends AndroidApplication{
             public void shareFile(Fi file){
             }
 
+            @Override
+            public Class<?> loadJar(Fi jar, String mainClass) throws Exception{
+                DexClassLoader loader = new DexClassLoader(jar.file().getPath(), getFilesDir().getPath(), null, getClassLoader());
+                return Class.forName(mainClass, true, loader);
+            }
+
             @Override
             public void showFileChooser(boolean open, String extension, Cons<Fi> cons){
+                showFileChooser(open, cons, extension);
+            }
+
+            void showFileChooser(boolean open, Cons<Fi> cons, String... extensions){
+                String extension = extensions[0];
+
                 if(VERSION.SDK_INT >= VERSION_CODES.Q){
                     Intent intent = new Intent(open ? Intent.ACTION_OPEN_DOCUMENT : Intent.ACTION_CREATE_DOCUMENT);
                     intent.addCategory(Intent.CATEGORY_OPENABLE);
-                    intent.setType(extension.equals("zip") && !open ? "application/zip" : "*/*");
+                    intent.setType(extension.equals("zip") && !open && extensions.length == 1 ? "application/zip" : "*/*");
+
                     addResultListener(i -> startActivityForResult(intent, i), (code, in) -> {
                         if(code == Activity.RESULT_OK && in != null && in.getData() != null){
                             Uri uri = in.getData();
@@ -108,7 +119,7 @@ public class AndroidLauncher extends AndroidApplication{
                     });
                 }else if(VERSION.SDK_INT >= VERSION_CODES.M && !(checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED &&
                     checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED)){
-                    chooser = new FileChooser(open ? "@open" : "@save", file -> file.extension().equalsIgnoreCase(extension), open, file -> {
+                    chooser = new FileChooser(open ? "@open" : "@save", file -> Structs.contains(extensions, file.extension().toLowerCase()), open, file -> {
                         if(!open){
                             cons.get(file.parent().child(file.nameWithoutExtension() + "." + extension));
                         }else{
@@ -124,10 +135,19 @@ public class AndroidLauncher extends AndroidApplication{
                         perms.add(Manifest.permission.READ_EXTERNAL_STORAGE);
                     }
                     requestPermissions(perms.toArray(new String[0]), PERMISSION_REQUEST_CODE);
+                }else{
+                    if(open){
+                        new FileChooser("@open", file -> Structs.contains(extensions, file.extension().toLowerCase()), true, cons).show();
                     }else{
                         super.showFileChooser(open, extension, cons);
                     }
                 }
+            }
+
+            @Override
+            public void showMultiFileChooser(Cons<Fi> cons, String... extensions){
+                showFileChooser(true, cons, extensions);
+            }
 
             @Override
             public void beginForceLandscape(){

core/src/mindustry/core/Platform.java

@@ -14,10 +14,18 @@ import mindustry.type.*;
 import mindustry.ui.dialogs.*;
 import rhino.*;
 
+import java.net.*;
+
 import static mindustry.Vars.*;
 
 public interface Platform{
 
+    /** Dynamically loads a jar file. */
+    default Class<?> loadJar(Fi jar, String mainClass) throws Exception{
+        URLClassLoader classLoader = new URLClassLoader(new URL[]{jar.file().toURI().toURL()}, ClassLoader.getSystemClassLoader());
+        return classLoader.loadClass(mainClass);
+    }
+
     /** Steam: Update lobby visibility.*/
     default void updateLobby(){}
 
@@ -121,7 +129,7 @@ public interface Platform{
     }
 
     /**
-     * Show a file chooser for multiple file types. Only supported on desktop.
+     * Show a file chooser for multiple file types.
      * @param cons Selection listener
      * @param extensions File extensions to filter
      */

core/src/mindustry/mod/Mods.java

@@ -25,7 +25,6 @@ import mindustry.type.*;
 import mindustry.ui.*;
 
 import java.io.*;
-import java.net.*;
 
 import static mindustry.Vars.*;
 
@@ -634,12 +633,11 @@ public class Mods implements Loadable{
             //make sure the main class exists before loading it; if it doesn't just don't put it there
             if(mainFile.exists()){
                 //mobile versions don't support class mods
-                if(mobile){
-                    throw new IllegalArgumentException("Java class mods are not supported on mobile.");
+                if(ios){
+                    throw new IllegalArgumentException("Java class mods are not supported on iOS.");
                 }
 
-                URLClassLoader classLoader = new URLClassLoader(new URL[]{sourceFile.file().toURI().toURL()}, ClassLoader.getSystemClassLoader());
-                Class<?> main = classLoader.loadClass(mainClass);
+                Class<?> main = platform.loadJar(sourceFile, mainClass);
                 metas.put(main, meta);
                 mainMod = (Mod)main.getDeclaredConstructor().newInstance();
             }else{

core/src/mindustry/net/CrashSender.java

@@ -33,7 +33,7 @@ public class CrashSender{
             + "OS: " + System.getProperty("os.name") + " x" + (OS.is64Bit ? "64" : "32") + "\n"
             + "Java Version: " + System.getProperty("java.version") + "\n"
             + "Java Architecture: " + System.getProperty("sun.arch.data.model") + "\n"
-            + mods.list().size + " Mods: " + mods.list().toString(", ", mod -> mod.name + ":" + mod.meta.version)
+            + mods.list().size + " Mods: " + (mods.list().isEmpty() ? "none" : mods.list().toString(", ", mod -> mod.name + ":" + mod.meta.version))
             + "\n\n" + error;
     }