1 package com.bumptech.glide.signature; 2 3 import com.bumptech.glide.load.Key; 4 5 import java.io.UnsupportedEncodingException; 6 import java.security.MessageDigest; 7 8 /** 9 * An empty key that is always equal to all other empty keys. 10 */ 11 public final class EmptySignature implements Key { 12 private static final EmptySignature EMPTY_KEY = new EmptySignature(); 13 obtain()14 public static EmptySignature obtain() { 15 return EMPTY_KEY; 16 } 17 EmptySignature()18 private EmptySignature() { 19 // Empty. 20 } 21 22 @Override updateDiskCacheKey(MessageDigest messageDigest)23 public void updateDiskCacheKey(MessageDigest messageDigest) throws UnsupportedEncodingException { 24 // Do nothing. 25 } 26 } 27