public class Main extends Activity {
 
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setContentView(R.layout.main);
  }
   
  @SuppressWarnings("unused")
  private void sayHello(String msg){
    Log.d("mmtag",msg);
  }
   
}

package com.example.dexclassloaderserver;
 
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.List;
 
import dalvik.system.DexClassLoader;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.util.Log;
 
public class MainActivity extends Activity {
 
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    useDexClassLoader();
  }
 
  @SuppressLint("NewApi")
  public void useDexClassLoader() {
 
    Intent mIntent = new Intent();
    mIntent.setClassName("com.example.dexclassloaderclient",
        "com.example.dexclassloaderclient.MainActivity");
    PackageManager pm = this.getPackageManager();
    List<ResolveInfo> mList = pm.queryIntentActivities(mIntent,
        PackageManager.MATCH_DEFAULT_ONLY);
    ResolveInfo info = mList.get(0);
     
    String apkPath = info.activityInfo.applicationInfo.sourceDir;
    String optPath = this.getCodeCacheDir().getAbsolutePath();
    String libPath = info.activityInfo.applicationInfo.nativeLibraryDir;
     
    DexClassLoader clsLoader = new DexClassLoader(apkPath, optPath,
        libPath, this.getClass().getClassLoader());
    try {
 
      Class cls = clsLoader
          .loadClass("com.example.dexclassloaderclient.MainActivity");
      Object obj = cls.newInstance();
      Method invokeMethod = cls.getDeclaredMethod("sayHello",
          new Class[] { String.class });
      invokeMethod.setAccessible(true);
      invokeMethod.invoke(obj, "hello world,DexClassLoader");
 
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

I/dex2oat (20250): dex2oat took 1.547s (threads: 4)
 
D/mmtag  (20229): hello world,DexClassLoader
 
D/OpenGLRenderer(20229): Render dirty regions requested: tru