TBaseApplication.java

package com.dpt.tbase.app.application;

import android.app.Application;
import android.text.TextUtils;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;
import com.dpt.tbase.app.base.utils.LruBitmapCache;
/**
 * 
 * @author dupengtao@cyou-inc.com
 *
 * 2014-4-13
 */
public class TBaseApplication extends Application {

    /**
     * Log or request TAG
     */
    public static final String TAG = TBaseApplication.class.getSimpleName();

    /**
     * Global request queue for Volley
     */
    private RequestQueue mRequestQueue;
    
    private ImageLoader mImageLoader;

    /**
     * A singleton instance of the application class for easy access in other places
     */
    private static TBaseApplication sInstance;

    @Override
    public void onCreate() {
        super.onCreate();

        // initialize the singleton
        sInstance = this;
    }

    /**
     * @return ApplicationController singleton instance
     */
    public static synchronized TBaseApplication getInstance() {
        return sInstance;
    }

    /**
     * @return The Volley Request queue, the queue will be created if it is null
     */
    public RequestQueue getRequestQueue() {
        // lazy initialize the request queue, the queue instance will be
        // created when it is accessed for the first time
        if (mRequestQueue == null) {
            mRequestQueue = Volley.newRequestQueue(getApplicationContext());
        }

        return mRequestQueue;
    }

    /**
     * Adds the specified request to the global queue, if tag is specified
     * then it is used else Default TAG is used.
     * 
     * @param req
     * @param tag
     */
    public <T> void addToRequestQueue(Request<T> req, String tag) {
        // set the default tag if tag is empty
        req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);

        VolleyLog.d("Adding request to queue: %s", req.getUrl());

        getRequestQueue().add(req);
    }

    /**
     * Adds the specified request to the global queue using the Default TAG.
     * 
     * @param req
     * @param tag
     */
    public <T> void addToRequestQueue(Request<T> req) {
        // set the default tag if tag is empty
        req.setTag(TAG);

        getRequestQueue().add(req);
    }

    /**
     * Cancels all pending requests by the specified TAG, it is important
     * to specify a TAG so that the pending/ongoing requests can be cancelled.
     * 
     * @param tag
     */
    public void cancelPendingRequests(Object tag) {
        if (mRequestQueue != null) {
            mRequestQueue.cancelAll(tag);
        }
    }
    
    public ImageLoader getImageLoader() {
        getRequestQueue();
        if (mImageLoader == null) {
            mImageLoader = new ImageLoader(this.mRequestQueue,
                    new LruBitmapCache());
        }
        return this.mImageLoader;
    }
}