非常感谢您在评论中使用哈希提示!
我最终通过伪随机散列(类似于Fisher-Yates随机播放)重新映射了字符顺序。其余代码是从String.compareTo
复制粘贴的:
private void magicSort(List<String> list,String seed) {
list.sort(new ShuffleComparator(seed));
}
public class ShuffleComparator implements Comparator<String> {
private static final long MAGIC = 0x5DEECE66DL;
private final String seed;
public ShuffleComparator(String seed) {
this.seed = seed;
}
@Override
public int compare(String s1,String s2) {
int len1 = s1.length();
int len2 = s2.length();
int lim = Math.min(len1,len2);
int seedLen = seed.length();
long random = seed.hashCode();
for (int k = 0; k < lim; k++) {
random = random * MAGIC + seed.charAt(k % seedLen);
char c1 = s1.charAt(k);
char c2 = s2.charAt(k);
if (c1 != c2) {
return ((random % (c1 + 0xFFFF)) & 0xFFFF) -
((random % (c2 + 0xFFFF)) & 0xFFFF) > 0 ? 1 : -1;
}
}
return (random > 0 ? 1 : -1) * (len1 - len2);
}
}
结果:
- 您可以随时对收藏进行随机排序
- 前缀相同的项目分组在一起(相似性)
- 唯一的资源(字符串种子)在JVM之间共享
- 对性能的影响可以忽略不计
- 零GC
示例:
seed: b85a9119-3a98-4491-b503-fc2cfdc344f3
[raccoon George,bird Carry,mice Dr Black,fish Silent,cat Tom,dog Woof]
[bird Frank,dog Woof]
[mice Dr Black,dog Woof]
seed: d5378421-d0ea-4b17-80e9-1de6a163bf38
[bird Carry,dog Woof,raccoon George,cat Tom]
[bird Frank,cat Tom]
[dog Woof,cat Tom]
seed: a5f94f60-1207-4f83-9723-bbab5e3b8075
[cat Tom,fish Silent]
[cat Tom,bird Frank,fish Silent]
seed: 4b77a61f-c639-42fc-96b2-e1add9f359e9
[bird Carry,fish Silent]
[bird Frank,fish Silent]
seed: 2dd78e21-d4ad-4e8a-b139-5d35fe2b0481
[dog Woof,cat Tom]
编辑#1
对于测试,我还实现了基于哈希的比较器,因此可以在此处发布。万一您不需要亲和力(例如我的情况),但需要纯随机播放:
private void magicSort(List<String> list,String seed) {
list.sort(new HashComparator(seed,"SHA-1"));
}
public class HashComparator implements Comparator<String> {
private static final long MAGIC = 0x5DEECE66DL;
private final ThreadLocal<MessageDigest> messageDigest;
private final byte[] seed;
private final int seedHash;
public HashComparator(String seed,String algorithm) {
this.seed = seed.getBytes(ISO_8859_1);
this.seedHash = seed.hashCode();
this.messageDigest = ThreadLocal.withInitial(() -> {
try {
return MessageDigest.getInstance(algorithm);
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e.getMessage(),e);
}
});
}
@Override
public int compare(String s1,String s2) {
if (s1.equals(s2)) {
return 0;
}
int diff = getSignature(s1).compareTo(getSignature(s2));
if (diff != 0) {
return diff;
}
long random = seedHash;
random = random * MAGIC + s1.hashCode();
random = random * MAGIC + s2.hashCode();
return ((random & 1) == 0 ? 1 : -1) * s1.compareTo(s2);
}
private ByteBuffer getSignature(String s) {
MessageDigest digest = messageDigest.get();
digest.reset();
digest.update(seed);
for (int i = 0,size = s.length(); i < size; i++) {
char c = s.charAt(i);
digest.update((byte) (c >> 8));
digest.update((byte) c);
}
return ByteBuffer.wrap(digest.digest());
}
}
结果:
- 您可以随时对收藏进行随机排序
- 纯随机播放(前缀相同的项目不相关)
- 唯一的资源(字符串种子)在JVM之间共享
示例:
8d465fde-9310-4b6c-9709-5cc395deb45e
[raccoon George,bird Carry]
[bird Frank,cat Tom]
[mice Dr Black,cat Tom]
6daa90dd-f7e7-4615-a45c-fefb0de10c20
[bird Carry,raccoon George]
[mice Dr Black,dog Woof]
9f30b259-c8d1-41f5-8221-40b17cb04260
[cat Tom,fish Silent]
94b6710f-3232-453d-8009-6d81658b2cca
[dog Woof,raccoon George]
[dog Woof,bird Frank]
[dog Woof,mice Dr Black]
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