Stop execution until User selects a button from the Alert dialog

To stop execution, I added a boolean variable called "loop" with the value true in the while loop. When the user selects a button from the Alert dialog, the "loop" variable is set to false. The code I added is in bold. Although I believe this practice should be avoided.

private class ConflictResolvingSyncHandler implements MobileServiceSyncHandler {

    **private boolean loop = true;**    

    @Override
    public JsonObject executeTableOperation(
            final RemoteTableOperationProcessor processor, final TableOperation operation)
            throws MobileServiceSyncHandlerException {

        final JsonObject clientItem = processor.getItem().getAsJsonObject();

        MobileServicePreconditionFailedExceptionBase ex = null;
        final JsonObject[] result = {null};
        try {
            result[0] = operation.accept(processor);
        } catch (MobileServicePreconditionFailedExceptionBase e) {
            ex = e;
        } catch (Throwable e) {
            ex = (MobileServicePreconditionFailedExceptionBase) e.getCause();
        }

        if (ex != null) {
            // A conflict was detected
            final AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                    context);                

            // set title
            alertDialogBuilder.setTitle("Conflict Detected");

            // set dialog message
            final MobileServicePreconditionFailedExceptionBase finalEx = ex;
            alertDialogBuilder
                    .setMessage("Choose winner")
                    .setCancelable(true)
                    .setPositiveButton("Server",new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,int id) {
                            // if this button is clicked, Server wins
                            JsonObject serverItem = finalEx.getValue();

                            if (serverItem == null) {
                                // Item not returned in the exception, retrieving it from the server
                                try {
                                    serverItem = mClient.getTable(operation.getTableName()).lookUp(operation.getItemId()).get();
                                } catch (Exception e) {
                                    try {
                                        throw new MobileServiceSyncHandlerException(e);
                                    } catch (MobileServiceSyncHandlerException e1) {
                                        e1.printStackTrace();
                                    }
                                }
                            }
                            result[0] = serverItem;
                            **loop = false;**                                
                        }
                    })
                    .setNegativeButton("Client",new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,int id) {
                            ToDoItem item = new ToDoItem();
                            // if this button is clicked, Client wins
                            result[0] = clientItem;
                            // Convert Json object to an item of my class
                            item.setId(clientItem.get("id").getAsString());
                            item.setText(clientItem.get("text").getAsString());
                            item.setComplete(clientItem.get("complete").getAsBoolean());
                            // update server table
                            updateItem(item);

                            new AsyncTask<Void, Void, Void>() {

                                @Override
                                protected Void doInBackground(Void... params) {
                                    try {
                                        // send changes to the server DB
                                        mClient.getSyncContext().push().get();

                                        // get query answer from the server DB
                                        mToDoTable.pull(mPullQuery).get();
                                        refreshItemsFromTable();
                                    } catch (final Exception exception) {
                                        runOnUiThread(new Runnable() {
                                            @Override
                                            public void run() {
                                                createAndShowDialog(exception, "Error");
                                            }
                                        });
                                    }
                                    return null;
                                }

                            }.execute();

                            **loop = false;**

                        }
                    });

            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    // create alert dialog
                    AlertDialog alertDialog = alertDialogBuilder.create();

                    // show it
                    alertDialog.show();

                }
            });


        }
        **while(loop){}**


        return result[0];

    }





    @Override
    public void onPushComplete(MobileServicePushCompletionResult result)
            throws MobileServiceSyncHandlerException {
    }


}