java, how does it work?

android/app/src/main/java/rehab/reality/alsuti/Encrypter.java

@@ -22,14 +22,18 @@ public class Encrypter {
     AssetManager am;
     String cjsString;
     String cliString;
-    Context context;
+    File outputDir;
     UploadActivity uploader;
     String ext;
+    String password;
+    String fileName;
 
-    public Encrypter(UploadActivity uploader, Context context) throws IOException {
-        this.context = context;
+    public Encrypter(UploadActivity uploader, Context context, String fileName, String password) throws IOException {
         this.uploader = uploader;
+        this.fileName = fileName;
+        this.password = password;
         am = context.getAssets();
+        this.outputDir = context.getCacheDir();
 
         Scanner cjsScanner = new Scanner(am.open("cryptojs.js"));
         cjsString = cjsScanner.useDelimiter("\\A").next();
@@ -38,11 +42,15 @@ public Encrypter(UploadActivity uploader, Context context) throws IOException {
         Scanner cliScanner = new Scanner(am.open("encrypt_file.js"));
         cliString = cliScanner.useDelimiter("\\A").next();
         cliScanner.close();
-
     }
 
-    public void encryptFile(String fileName, String password) throws IOException, JSException {
-        byte[] b = FileUtils.readFileToByteArray(new File(fileName));
+    public void runEncryption() {
+        byte[] b = new byte[0];
+        try {
+            b = FileUtils.readFileToByteArray(new File(fileName));
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
 
         String content = "YW5kcm9pZHN1Y2tz" + android.util.Base64.encodeToString(b, android.util.Base64.DEFAULT);
 
@@ -57,63 +65,36 @@ public void encryptFile(String fileName, String password) throws IOException, JS
 
         ext = fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length());
 
-        new RunEncryption(this, jsCode, password).execute();
-        Log.w("progress", "started encryption");
-    }
+        Log.w("progress", "built string");
+
+        JSContext js = new JSContext();
+        try {
+            js.evaluateScript(jsCode);
+        } catch (JSException e) {
+            e.printStackTrace();
+        }
+        Log.w("progress", "built ciphertext");
+        String ret = "";
+        try {
+            ret = js.property("result").toString();
+        } catch (JSException e) {
+            e.printStackTrace();
+        }
+        Log.w("progress", "got ciphertext");
 
-    void done(String cipherText) {
-        File outputDir = context.getCacheDir(); // context being the Activity pointer
         File outputFile = null;
         try {
             outputFile = File.createTempFile("alsutiTemp", "." + ext, outputDir);
             PrintWriter writer = new PrintWriter(outputFile, "UTF-8");
-            writer.print(cipherText);
+            writer.print(ret);
             writer.close();
         } catch (IOException e) {
             e.printStackTrace();
-            Toast.makeText(context, e.getMessage(), Toast.LENGTH_LONG).show();
+            Log.w("error", String.valueOf(e.getStackTrace()));
         }
+        Log.w("progress", "written temp file");
 
-        Log.w("progress", "got the ciphertext and written!");
-
+        Log.w("progress", "done encryption");
         uploader.doneEncryption(outputFile.getAbsolutePath());
     }
-
-    private class RunEncryption extends AsyncTask <String, String, String> {
-        Encrypter encrypter;
-        String password;
-        String jsCode;
-
-        public RunEncryption(Encrypter enc, String jsCode, String password) {
-            encrypter = enc;
-            this.password = password;
-            this.jsCode = jsCode;
-        }
-
-        @Override
-        protected String doInBackground(String... params) {
-            JSContext js = new JSContext();
-            try {
-                js.evaluateScript(jsCode);
-            } catch (JSException e) {
-                e.printStackTrace();
-            }
-            String ret = "";
-            try {
-                ret = js.property("result").toString();
-            } catch (JSException e) {
-                e.printStackTrace();
-            }
-
-            Log.w("progress", "done encryption");
-            return ret;
-        }
-
-        @Override
-        protected void onPostExecute(String result) {
-
-            Log.w("progress", "calling callback");
-            encrypter.done(result);
-        }
-    }
 }

android/app/src/main/java/rehab/reality/alsuti/UploadActivity.java

@@ -81,8 +81,8 @@ public void onClickBtn(View v) throws IOException, JSException {
             encrypted = true;
             progressBox.setText("Encrypting...");
             try {
-                encrypter = new Encrypter(this, getBaseContext());
-                encrypter.encryptFile(waitingFileName, password);
+                encrypter = new Encrypter(this, getBaseContext(), waitingFileName, password);
+                encrypter.runEncryption();
             } catch (IOException e) {
                 e.printStackTrace();
                 Toast.makeText(this, "unable to load things", Toast.LENGTH_LONG).show();
@@ -104,11 +104,16 @@ public void onClickBtn(View v) throws IOException, JSException {
         }
     }
 
-    public void doneEncryption(String result) {
-        EditText progressBox = (EditText) findViewById(R.id.editText);
-        waitingFileName = result;
-        progressBox.setText("Uploading...");
-        postFile();
+    public void doneEncryption(final String result) {
+        runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                EditText progressBox = (EditText) findViewById(R.id.editText);
+                waitingFileName = result;
+                progressBox.setText("Uploading...");
+                postFile();
+            }
+        });
     }
 
     @Override