Main.java Source code

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Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Apache License 

import android.content.Context;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;

import android.text.TextUtils;

import android.util.Log;

public class Main {
    public static final String TAG = "GcmUtils";
    private static SharedPreferences sPrefs;
    private static final String GCM_PREFS_NAME = "gcm_prefs";
    public static final String KEY_GCM_REGISTRATION_ID = "gcm_registration_id";
    public static final String KEY_GCM_SERVER_EXPIRATION_TIME = "gcm_server_expiration_time";
    public static final String KEY_GCM_APP_VERSION = "gcm_app_version";

    /**
     * Retrieves the GCM registration Id. Will require a new one if the app is
     * updated or if the regId is expired.
     *
     * @param context
     * @return
     */
    public static String getRegistrationId(Context context) {
        String regId = getGcmRegistrationIdFromPreferences(context);

        if (TextUtils.isEmpty(regId)) {
            Log.v(TAG, "No GCM Registration Id found.");
            return "";
        }
        // Check if app was updated. if so, it must clear registration id to
        // avoid a race condition if GCM sends a message
        int registeredVersion = getGcmAppVersion(context);
        int currentVersion = getAppVersion(context);
        if (registeredVersion != currentVersion || isRegistrationExpired(context)) {
            // TODO - Add isRegistrationExpired?
            Log.v(TAG, "App version changed.");
            return "";
        }
        return regId;
    }

    public static String getGcmRegistrationIdFromPreferences(Context context) {
        buildSharedPreferences(context);
        return sPrefs.getString(KEY_GCM_REGISTRATION_ID, null);
    }

    public static int getGcmAppVersion(Context context) {
        buildSharedPreferences(context);
        return sPrefs.getInt(KEY_GCM_APP_VERSION, -1);
    }

    private static int getAppVersion(Context context) {
        try {
            PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
            return packageInfo.versionCode;
        } catch (NameNotFoundException e) {
            Log.e(TAG, "Could not get package name.", e);
        }
        return 0;
    }

    /**
     * Determines if the current registration with GCM is expired or not.
     */
    private static boolean isRegistrationExpired(Context context) {
        long expirationTime = getGcmExpiredLong(context);
        return System.currentTimeMillis() > expirationTime;
    }

    private static void buildSharedPreferences(Context context) {
        if (sPrefs == null) {
            sPrefs = context.getSharedPreferences(GCM_PREFS_NAME, Context.MODE_PRIVATE);
        }
    }

    public static long getGcmExpiredLong(Context context) {
        buildSharedPreferences(context);
        return sPrefs.getLong(KEY_GCM_SERVER_EXPIRATION_TIME, -1);
    }
}