android 根据apk获取其包名，并根据包名启动app

//根据apk获取应用包名
private void getApkInfo(){PackageManager pm = this.getPackageManager();
    String path= Environment.getExternalStorageDirectory()+"/demo.apk";//apk保存路径（sd卡根目录下）
    PackageInfo info = pm.getPackageArchiveInfo(path, PackageManager.GET_ACTIVITIES);
    ApplicationInfo appInfo = null;       if (info != null) {        appInfo = info.applicationInfo;        name = appInfo.packageName;//此为apk包名    }} 
 


//根据包名启动app
public void startAPP(String appPackageName){try{Intent intent = this.getPackageManager().getLaunchIntentForPackage(appPackageName);
        startActivity(intent);        
    }catch(Exception e){Toast.makeText(this, "没有安装", Toast.LENGTH_LONG).show();
    }
}