Send .dex file via post request android studio - file

Question

For my own purposes, I want to send other app's dex file to a remote server and get the answer.
I've used answers that I found here. I tried to create a simple example at first, just to connect to the server and upload the dex file. So far I haven't managed to extract dex from other apps , so I thought of using a dex file I already have.
As I've read, not common files should be stored either to "/res/raw" or "assets"
I tried many ways to load it as a File but none of them worked . The path I used in all cases were found in right click on file -> copy reference.
create a res folder under /raw and
File f = new File("res/raw/filename.dex");
Create a new assets folder under /app
File f = new File("filename.dex");
Create assets folder under /main
File f = new File("main/assets/filename.dex");
and so on.
The only way I managed to do so is by using InputStream
Inputstream in = getResources().openRawResources(R.raw.filename_without_dex)
but I couldn't cast it to File, so I dropped this solution.I want to have it as a File cause the following POST request must be a multipart/form.
In java, the way to "load" a file is straightforward. Why not in android ?

Answer 1

A truly ugly, quick and dirty solution.
No error check or cleanup.
But it works.
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.os.Bundle;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;
public class MainActivity extends ActionBarActivity {
final String TAG = "GetDex";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getAppPaths(); // to list all packages
String s = "/data/app/SoftKeyboard/SoftKeyboard.apk"; // a sample package
byte[] b = getFile(s);
byte[] dex = unzipDex(b, s);
Log.d(TAG, String.format("DEX size is %d", dex.length));
}
List<String> getAppPaths() {
final PackageManager pm = getPackageManager();
//get a list of installed apps.
List<ApplicationInfo> packages = pm.getInstalledApplications(PackageManager.GET_META_DATA);
List<String> paths = new ArrayList<>();
for (ApplicationInfo packageInfo : packages) {
Log.d(TAG, "Installed package :" + packageInfo.packageName);
Log.d(TAG, "Apk file path:" + packageInfo.sourceDir);
paths.add(packageInfo.sourceDir);
}
return paths;
}
byte[] getFile(String filename) {
try {
RandomAccessFile f = new RandomAccessFile(filename, "r");
byte[] b = new byte[(int)f.length()];
f.readFully(b);
return b;
} catch(IOException exception) {
exception.printStackTrace();
}
return null;
}
public byte[] unzipDex(byte[] bytes, String filename) {
try{
ZipFile zipFile = new ZipFile(filename);
ZipInputStream zis = new ZipInputStream(new ByteArrayInputStream(bytes));
ZipEntry ze = zis.getNextEntry();
while(ze!=null){
String entryName = ze.getName();
if(!entryName.equals("classes.dex")) {
ze = zis.getNextEntry();
continue;
}
InputStream is = zipFile.getInputStream(ze);
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int nRead;
byte[] data = new byte[16384];
while ((nRead = is.read(data, 0, data.length)) != -1) {
buffer.write(data, 0, nRead);
}
buffer.flush();
return buffer.toByteArray();
}
System.out.println("Done");
}catch(IOException ex){
ex.printStackTrace();
}
return null;
}
}