gauravssnl · January 30, 2024 14:57 · Jan 24, 2022
diff --git a/InMemoryDexClassLoaderFactory.java b/InMemoryDexClassLoaderFactory.java
@@ -0,0 +1,46 @@
+import android.app.AppComponentFactory;
+import android.content.pm.ApplicationInfo;
+import android.util.Log;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.Channels;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.zip.ZipFile;
+
+import dalvik.system.InMemoryDexClassLoader;
+
+public class InMemoryDexClassLoaderFactory extends AppComponentFactory {
+
+    private static ClassLoader classLoader;
+
+    private static void readDexes(ZipFile apkFile, List<ByteBuffer> dexFiles) throws IOException {
+        int secondary = 2;
+        for (var dexFile = apkFile.getEntry("classes.dex"); dexFile != null;
+             dexFile = apkFile.getEntry("classes" + secondary + ".dex"), secondary++) {
+            var in = apkFile.getInputStream(dexFile);
+            var byteBuffer = ByteBuffer.allocate(in.available());
+            byteBuffer.mark();
+            Channels.newChannel(in).read(byteBuffer);
+            byteBuffer.reset();
+            dexFiles.add(byteBuffer);
+        }
+    }
+
+    @Override
+    public ClassLoader instantiateClassLoader(ClassLoader cl, ApplicationInfo aInfo) {
+        if (classLoader != null) return classLoader;
+        var buffers = new ArrayList<ByteBuffer>();
+        try (var zipFile = new ZipFile(aInfo.sourceDir)) {
+            readDexes(zipFile, buffers);
+        } catch (IOException e) {
+            Log.e(App.TAG, "Can not load " + aInfo.sourceDir, e);
+            return cl;
+        }
+        var dexfiles = new ByteBuffer[buffers.size()];
+        buffers.toArray(dexfiles);
+        classLoader = new InMemoryDexClassLoader(dexfiles, aInfo.nativeLibraryDir, cl.getParent());
+        return classLoader;
+    }
+}