android 内存高速缓存bitmap
private final HashMap<String, SoftReference<T>> mCache;public void put(String key, T value) {mCache.put(key, new SoftReference<T>(value));}public T get(String key, ValueBuilder builder) {T value = null;SoftReferece<T> reference = mCache.get(key);if (reference != null) {value = reference.get();}if (value == null) {value = builder.build(key);mCache.put(key, new SoftReference<T>(value));}return value;}