缓存

public class BaseAppliction extends Application {
@Override
public void onCreate() {
super.onCreate();
File cacheFile = null;
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
File rootSD = Environment.getExternalStorageDirectory();
cacheFile = new File(rootSD, “pic”);
if (!cacheFile.exists()) {
cacheFile.mkdirs();
}
}

    DiskCache diskCache = null;
    try {
        diskCache = new LruDiskCache(cacheFile, new Md5FileNameGenerator(), 50 * 1024 * 1024);
    } catch (IOException e) {
        e.printStackTrace();
    }

    DisplayImageOptions options = new DisplayImageOptions.Builder()
            .cacheOnDisk(true)
            .cacheInMemory(true)
            .bitmapConfig(Bitmap.Config.RGB_565)
            .showImageOnFail(R.mipmap.ic_launcher)
            .showImageOnLoading(R.mipmap.ic_launcher)
            .showImageForEmptyUri(R.mipmap.ic_launcher)
            .build();

    ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(this)
            .diskCache(diskCache)
            .memoryCache(new LruMemoryCache(12 * 1024 * 1024))
            .threadPoolSize(3)
            .defaultDisplayImageOptions(options)
            .build();

    ImageLoader.getInstance().init(configuration);

}

}