Deconstructed APK prototyping

apk/hijack/org/chromium/deconstructed/JavaInstaller.java

+package org.chromium.deconstructed;
+
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.util.Log;
+
+import java.io.File;
+import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.List;
+
+public class JavaInstaller {
+    private static final String TAG = "org.chromium.deconstructed.JavaInstaller";
+    private static final String SECONDARY_FOLDER_NAME =
+            "code_cache" + File.separator + "deconstructed-dexes";
+
+    public static void install(Context context, File dexDir)
+            throws NoSuchFieldException, NoSuchMethodException, InvocationTargetException {
+        File[] dexFiles = dexDir.listFiles();
+        for (File f : dexFiles) {
+            if (!isValidDex(f)) {
+                return;
+            }
+        }
+        ApplicationInfo appInfo = context.getApplicationInfo();
+        File optimizedDir = new File(appInfo.dataDir, SECONDARY_FOLDER_NAME);
+        install(context.getClassLoader(), Arrays.asList(dexFiles), optimizedDir);
+    }
+
+    private static boolean isValidDex(File f) {
+        // TODO
+        return true;
+    }
+
+    private static void install(ClassLoader loader, List<File> additionalClassPathEntries,
+            File optimizedDirectory) throws IllegalArgumentException, NoSuchFieldException,
+                                            NoSuchMethodException, InvocationTargetException {
+        optimizedDirectory.mkdirs();
+        Object dexPathList = Reflect.getField(loader, "pathList");
+        ArrayList<IOException> suppressedExceptions = new ArrayList<IOException>();
+        Object[] dexElements = (Object[]) Reflect.getField(dexPathList, "dexElements");
+        Object[] injectedElements = makeDexElements(dexPathList, new ArrayList<File>(additionalClassPathEntries), optimizedDirectory);
+        Reflect.setField(
+                dexPathList, "dexElements", Reflect.concatArrays(dexElements, injectedElements));
+    }
+
+    private static Object[] makeDexElements(Object dexPathList, ArrayList<File> files,
+            File optimizedDirectory) throws NoSuchMethodException, InvocationTargetException {
+        ArrayList<IOException> suppressedExceptions = new ArrayList<IOException>();
+        return (Object[]) Reflect.invokeMethod(dexPathList, "makeDexElements", files, optimizedDirectory, suppressedExceptions);
+    }
+
+}