How to access classes.dex of an Android Application?

问题

When an activity is launched, the classes.dex file is loaded by the system and start executing the instructions. I need to get readonly access to the classes.dex of the same application under which the current activity is executing.

After searching for hours on the net, I could only infer that the Android Security system does not allow access to the application sandbox.

However, i need readonly access to the classes.dex file in order to accomplish my task.

Does anyone have a insight on this?

Thanks in advance!

回答1:

Depends on what you are trying to do, but you can access the DexFile :

String sourceDir = context.getApplicationInfo().sourceDir;
DexFile dexFile = new DexFile(sourceDir);

it gives you a http://developer.android.com/reference/dalvik/system/DexFile.html which you can enumerate, and load classes from.

回答2:

You may be able to obtain an InputStream for "classes.dex" in the following way:

Retrieve the path to the apk container of your application.
Retrieve the "classes.dex" entry inside your apk container thanks to JarFile class.
Get an Input Stream for it.

Here is a snippet of code to exemplify:

        // Get the path to the apk container.
        String apkPath = getApplicationInfo().sourceDir;
        JarFile containerJar = null;

        try {

            // Open the apk container as a jar..
            containerJar = new JarFile(apkPath);

            // Look for the "classes.dex" entry inside the container.
            ZipEntry ze = containerJar.getEntry("classes.dex");

            // If this entry is present in the jar container 
            if (ze != null) {

                 // Get an Input Stream for the "classes.dex" entry
                 InputStream in = containerJar.getInputStream(ze);

                 // Perform read operations on the stream like in.read();
                 // Notice that you reach this part of the code
                 // only if the InputStream was properly created;
                 // otherwise an IOException is raised
            }   

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (containerJar != null)
                try {
                    containerJar.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
        }

Hope it helps!

来源：https://stackoverflow.com/questions/10122918/how-to-access-classes-dex-of-an-android-application

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android