FileCache.java

package com.bourke.finch.lazylist;

import android.content.Context;

import java.io.File;

public class FileCache {

    private File cacheDir;

    public FileCache(Context context){
        /* Find the dir to save cached images */
        if (android.os.Environment.getExternalStorageState().equals(
                    android.os.Environment.MEDIA_MOUNTED)) {
            cacheDir = new File(context.getCacheDir(), "lazylist");
        }
        if(!cacheDir.exists()) {
            cacheDir.mkdirs();
        }
    }

    public File getFile(String url){
        //I identify images by hashcode. Not a perfect solution, good for the demo.
        String filename=String.valueOf(url.hashCode());
        //Another possible solution (thanks to grantland)
        //String filename = URLEncoder.encode(url);
        File f = new File(cacheDir, filename);
        return f;

    }

    public void clear(){
        File[] files=cacheDir.listFiles();
        if(files==null)
            return;
        for(File f:files)
            f.delete();
    }

}