wemall app中基于JAVA获取和保存图片的代码

wemall-mobile是基于WeMall的android app商城，只需要在原商城目录下上传接口文件即可完成服务端的配置，客户端可定制修改。分享其中关于 保存正在下载的图片URL集合和图片三种获取方式管理者，网络URL获取、内存缓存获取、外部文件缓存获取的代码供技术员学习参考使用。

 

package com.inuoer.util;import java.lang.ref.SoftReference;import java.util.HashMap;import java.util.HashSet;import java.util.Map;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import android.content.Context;import android.graphics.Bitmap;import android.os.Handler;public class AsyncImageLoader {// 保存正在下载的图片URL集合，避免重复下载用private static HashSet<String> sDownloadingSet;// 软引用内存缓存private static Map<String, SoftReference<Bitmap>> sImageCache;// 图片三种获取方式管理者，网络URL获取、内存缓存获取、外部文件缓存获取private static LoaderImpl impl;// 线程池相关private static ExecutorService sExecutorService;// 通知UI线程图片获取ok时使用private Handler handler;/** * 异步加载图片完毕的回调接口 */public interface ImageCallback {/** * 回调函数 *  * @param bitmap *            : may be null! * @param imageUrl */public void onImageLoaded(Bitmap bitmap, String imageUrl);}static {sDownloadingSet = new HashSet<String>();sImageCache = new HashMap<String, SoftReference<Bitmap>>();impl = new LoaderImpl(sImageCache);}public AsyncImageLoader(Context context) {handler = new Handler();startThreadPoolIfNecessary();String defaultDir = context.getCacheDir().getAbsolutePath();setCachedDir(defaultDir);}/** * 是否缓存图片至/data/data/package/cache/目录 默认不缓存 */public void setCache2File(boolean flag) {impl.setCache2File(flag);}/** * 设置缓存路径，setCache2File(true)时有效 */public void setCachedDir(String dir) {impl.setCachedDir(dir);}/** 开启线程池 */public static void startThreadPoolIfNecessary() {if (sExecutorService == null || sExecutorService.isShutdown()|| sExecutorService.isTerminated()) {sExecutorService = Executors.newFixedThreadPool(3);// sExecutorService = Executors.newSingleThreadExecutor();}}/** * 异步下载图片，并缓存到memory中 *  * @param url * @param callback *            see ImageCallback interface */public void downloadImage(final String url, final ImageCallback callback) {downloadImage(url, true, callback);}/** *  * @param url * @param cache2Memory *            是否缓存至memory中 * @param callback */public void downloadImage(final String url, final boolean cache2Memory,final ImageCallback callback) {if (sDownloadingSet.contains(url)) {//Log.i("AsyncImageLoader", "###该图片正在下载，不能重复下载！");return;}Bitmap bitmap = impl.getBitmapFromMemory(url);if (bitmap != null) {if (callback != null) {callback.onImageLoaded(bitmap, url);}} else {// 从网络端下载图片sDownloadingSet.add(url);sExecutorService.submit(new Runnable() {@Overridepublic void run() {final Bitmap bitmap = impl.getBitmapFromUrl(url,cache2Memory);handler.post(new Runnable() {@Overridepublic void run() {if (callback != null)callback.onImageLoaded(bitmap, url);sDownloadingSet.remove(url);}});}});}}/** * 预加载下一张图片，缓存至memory中 *  * @param url */public void preLoadNextImage(final String url) {// 将callback置为空，只将bitmap缓存到memory即可。downloadImage(url, null);}}

wemall-mobile详情下载地址：http://www.koahub.com/home/product/56

wemall官网地址：http://www.wemallshop.com

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