package com.nostra13.universalimageloader.cache.disc.naming;

/**

 * Generates names for files at disk cache

 */

public interface FileNameGenerator {

    /** Generates unique file name for image defined by URI */

    String generate(String imageUri);

}

package com.nostra13.universalimageloader.cache.disc.naming;

/**

 * Names image file as image URI {@linkplain String#hashCode() hashcode}

 */

public class HashCodeFileNameGenerator implements FileNameGenerator {

    @Override

    public String generate(String imageUri) {

        return String.valueOf(imageUri.hashCode());

    }

}

package com.nostra13.universalimageloader.cache.disc.naming;

import com.nostra13.universalimageloader.utils.L;

import java.math.BigInteger;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

/**

 * Names image file as MD5 hash of image URI

 */

public class Md5FileNameGenerator implements FileNameGenerator {

    private static final String HASH_ALGORITHM = "MD5";

    private static final int RADIX = 10 + 26; // 10 digits + 26 letters

    @Override

    public String generate(String imageUri) {

        byte[] md5 = getMD5(imageUri.getBytes());

        BigInteger bi = new BigInteger(md5).abs();

        return bi.toString(RADIX);

    }

    private byte[] getMD5(byte[] data) {

        byte[] hash = null;

        try {

            MessageDigest digest = MessageDigest.getInstance(HASH_ALGORITHM);

            digest.update(data);

            hash = digest.digest();

        } catch (NoSuchAlgorithmException e) {

            L.e(e);

        }

        return hash;

    }

}