Question

I have the following class:

package com.somedomain.enigma;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.util.Log;

public class APICall {
    private String DEBUG_TAG = "enigma";

    public void register(Context context, Intent intent) {
        final String URL = "http://somedomain.com:8888/register";

        String registrationId = intent.getStringExtra("registration_id");
        String error = intent.getStringExtra("error");
        String unregistered = intent.getStringExtra("unregistered"); 

        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost(URL);

        // Send a POST to the server to register the device
        if (registrationId != null) {
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
            nameValuePairs.add(new BasicNameValuePair("registrationId", registrationId));
            try {
                httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                HttpResponse response = httpclient.execute(httppost);
                int responseCode = response.getStatusLine().getStatusCode();
                if(responseCode == 200) {
                    SharedPreferences settings = context.getPreferences(Context.MODE_PRIVATE);
                    SharedPreferences.Editor editor = settings.edit();
                    editor.putString("registrationId", registrationId);
                    editor.commit();
                    Log.d(DEBUG_TAG, "Device registered successfully");
                } else {
                    Log.d(DEBUG_TAG, "Device registration failed");
                }
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ClientProtocolException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

        if (unregistered != null) {
            // get old registration ID from shared preferences
            // notify 3rd-party server about the unregistered ID
            Log.d(DEBUG_TAG, "Unregister request");
        } 

        if (error != null) {
            if ("SERVICE_NOT_AVAILABLE".equals(error)) {
               // optionally retry using exponential back-off
                Log.d(DEBUG_TAG, "Service not available");
            } else {
                // Unrecoverable error, log it
                Log.d(DEBUG_TAG, "Received error: " + error);
            }
        }
    }
}

and I am receiving the error "The method getPreferences(int) is undefined for the type Context" on this line:

SharedPreferences settings = context.getPreferences(Context.MODE_PRIVATE);

I am passing in context from the previous method using Context context = getApplicationContext(); any ideas how to fix this issue?

Answer 1

Try instead

SharedPreferences settings = context.getSharedPreferences("MyPreferencesName",Context.MODE_PRIVATE);

Straight from the documentation, there is no getPreferences method, but there is a getSharedPreferences() method.

Note that if you are using a default SharedPreferences file, you can do

SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(context); 

Edit: getSharedPreferences() is only part of the Activity class. This method is actually a convenience method.

This simply calls the underlying getSharedPreferences(String, int)
method by passing in this activity’s class name as the preferences
name.

So if you are absolutely sure that context is an instance of Activity you can change the method declaration:

public void register(Activity activity, Intent intent) {

or cast

SharedPreferences settings = ((Activity)context).getPreferences(Context.MODE_PRIVATE);

However, if context is not an instance of Activity, you will have to rely on the other approaches for accessing Preferences.