Java工具集-哈希(HashUtil)
简单工具类
写作初衷:由于日常开发经常需要用到很多工具类,经常根据需求自己写也比较麻烦
网上好了一些工具类例如commom.lang3或者hutool或者Jodd这样的开源工具,但是
发现他们之中虽然设计不错,但是如果我想要使用,就必须要引入依赖并且去维护依赖,有些
甚至会有存在版本编译不通过问题,故此想要写作一个每个类都可以作为独立工具类使用
每个使用者只需要复制该类,到任何项目当中都可以使用,所以需要尊从以下两个原则才能
做到.在此诚邀各位大佬参与.可以把各自用过的工具,整合成只依赖JDK,每个类都能够单独
使用的工具.每个人当遇到业务需求需要使用的时候,只需要到这里单独拷贝一个即可使用.
抛弃传统的需要引入依赖的烦恼.让大家一起来解决你所面临的业务问题吧!
介绍
遵从两大原则
- 1.绝不依赖JDK以外的源码
- 2.牺牲代码复用性,每个类都必须是单独的组件,绝不互相引用,做到完全解耦
package *;
/**
* @program: simple_tools
* @description:
* @author: ChenWenLong
* @create: 2019-05-23 16:01
**/
public class HashUtil {
private static final int R1_32 = 15;
private static final int R2_32 = 13;
private static final int M_32 = 5;
private static final int N_32 = 0xe6546b64;
private static final int C1_32 = 0xcc9e2d51;
private static final int C2_32 = 0x1b873593;
private static final int DEFAULT_SEED = 0;
/**
* 加法hash
*
* @param key 字符串
* @param prime 一个质数
* @return hash结果
*/
public static int additiveHash(String key, int prime) {
int hash, i;
for (hash = key.length(), i = 0; i < key.length(); i++) {
hash += key.charAt(i);
}
return hash % prime;
}
/**
* 旋转hash
*
* @param key 输入字符串
* @param prime 质数
* @return hash值
*/
public static int rotatingHash(String key, int prime) {
int hash, i;
for (hash = key.length(), i = 0; i < key.length(); ++i) {
hash = (hash << 4) ^ (hash >> 28) ^ key.charAt(i);
}
return hash % prime;
}
/**
* 一次一个hash
*
* @param key 输入字符串
* @return 输出hash值
*/
public static int oneByOneHash(String key) {
int hash, i;
for (hash = 0, i = 0; i < key.length(); ++i) {
hash += key.charAt(i);
hash += (hash << 10);
hash ^= (hash >> 6);
}
hash += (hash << 3);
hash ^= (hash >> 11);
hash += (hash << 15);
return hash;
}
/**
* Bernstein's hash
*
* @param key 输入字节数组
* @return 结果hash
*/
public static int bernstein(String key) {
int hash = 0;
int i;
for (i = 0; i < key.length(); ++i) {
hash = 33 * hash + key.charAt(i);
}
return hash;
}
/**
* Universal Hashing
*
* @param key 字节数组
* @param mask 掩码
* @param tab tab
* @return hash值
*/
public static int universal(char[] key, int mask, int[] tab) {
int hash = key.length, i, len = key.length;
for (i = 0; i < (len << 3); i += 8) {
char k = key[i >> 3];
if ((k & 0x01) == 0) {
hash ^= tab[i + 0];
}
if ((k & 0x02) == 0) {
hash ^= tab[i + 1];
}
if ((k & 0x04) == 0) {
hash ^= tab[i + 2];
}
if ((k & 0x08) == 0) {
hash ^= tab[i + 3];
}
if ((k & 0x10) == 0) {
hash ^= tab[i + 4];
}
if ((k & 0x20) == 0) {
hash ^= tab[i + 5];
}
if ((k & 0x40) == 0) {
hash ^= tab[i + 6];
}
if ((k & 0x80) == 0) {
hash ^= tab[i + 7];
}
}
return (hash & mask);
}
/**
* Zobrist Hashing
*
* @param key 字节数组
* @param mask 掩码
* @param tab tab
* @return hash值
*/
public static int zobrist(char[] key, int mask, int[][] tab) {
int hash, i;
for (hash = key.length, i = 0; i < key.length; ++i) {
hash ^= tab[i][key[i]];
}
return (hash & mask);
}
/**
* 改进的32位FNV算法1
*
* @param data 数组
* @return hash结果
*/
public static int fnvHash(byte[] data) {
final int p = 16777619;
int hash = (int) 2166136261L;
for (byte b : data) {
hash = (hash ^ b) * p;
}
hash += hash << 13;
hash ^= hash >> 7;
hash += hash << 3;
hash ^= hash >> 17;
hash += hash << 5;
return hash;
}
/**
* 改进的32位FNV算法1
*
* @param data 字符串
* @return hash结果
*/
public static int fnvHash(String data) {
final int p = 16777619;
int hash = (int) 2166136261L;
for (int i = 0; i < data.length(); i++) {
hash = (hash ^ data.charAt(i)) * p;
}
hash += hash << 13;
hash ^= hash >> 7;
hash += hash << 3;
hash ^= hash >> 17;
hash += hash << 5;
return hash;
}
/**
* Thomas Wang的算法，整数hash
*
* @param key 整数
* @return hash值
*/
public static int intHash(int key) {
key += ~(key << 15);
key ^= (key >>> 10);
key += (key << 3);
key ^= (key >>> 6);
key += ~(key << 11);
key ^= (key >>> 16);
return key;
}
/**
* RS算法hash
*
* @param str 字符串
* @return hash值
*/
public static int rsHash(String str) {
int b = 378551;
int a = 63689;
int hash = 0;
for (int i = 0; i < str.length(); i++) {
hash = hash * a + str.charAt(i);
a = a * b;
}
return hash & 0x7FFFFFFF;
}
/**
* JS算法
*
* @param str 字符串
* @return hash值
*/
public static int jsHash(String str) {
int hash = 1315423911;
for (int i = 0; i < str.length(); i++) {
hash ^= ((hash << 5) + str.charAt(i) + (hash >> 2));
}
return hash & 0x7FFFFFFF;
}
/**
* PJW算法
*
* @param str 字符串
* @return hash值
*/
public static int pjwHash(String str) {
int bitsInUnsignedInt = 32;
int threeQuarters = (bitsInUnsignedInt * 3) / 4;
int oneEighth = bitsInUnsignedInt / 8;
int highBits = 0xFFFFFFFF << (bitsInUnsignedInt - oneEighth);
int hash = 0;
int test = 0;
for (int i = 0; i < str.length(); i++) {
hash = (hash << oneEighth) + str.charAt(i);
if ((test = hash & highBits) != 0) {
hash = ((hash ^ (test >> threeQuarters)) & (~highBits));
}
}
return hash & 0x7FFFFFFF;
}
/**
* ELF算法
*
* @param str 字符串
* @return hash值
*/
public static int elfHash(String str) {
int hash = 0;
int x = 0;
for (int i = 0; i < str.length(); i++) {
hash = (hash << 4) + str.charAt(i);
if ((x = (int) (hash & 0xF0000000L)) != 0) {
hash ^= (x >> 24);
hash &= ~x;
}
}
return hash & 0x7FFFFFFF;
}
/**
* BKDR算法
*
* @param str 字符串
* @return hash值
*/
public static int bkdrHash(String str) {
int seed = 131; // 31 131 1313 13131 131313 etc..
int hash = 0;
for (int i = 0; i < str.length(); i++) {
hash = (hash * seed) + str.charAt(i);
}
return hash & 0x7FFFFFFF;
}
/**
* SDBM算法
*
* @param str 字符串
* @return hash值
*/
public static int sdbmHash(String str) {
int hash = 0;
for (int i = 0; i < str.length(); i++) {
hash = str.charAt(i) + (hash << 6) + (hash << 16) - hash;
}
return hash & 0x7FFFFFFF;
}
/**
* DJB算法
*
* @param str 字符串
* @return hash值
*/
public static int djbHash(String str) {
int hash = 5381;
for (int i = 0; i < str.length(); i++) {
hash = ((hash << 5) + hash) + str.charAt(i);
}
return hash & 0x7FFFFFFF;
}
/**
* DEK算法
*
* @param str 字符串
* @return hash值
*/
public static int dekHash(String str) {
int hash = str.length();
for (int i = 0; i < str.length(); i++) {
hash = ((hash << 5) ^ (hash >> 27)) ^ str.charAt(i);
}
return hash & 0x7FFFFFFF;
}
/**
* AP算法
*
* @param str 字符串
* @return hash值
*/
public static int apHash(String str) {
int hash = 0;
for (int i = 0; i < str.length(); i++) {
hash ^= ((i & 1) == 0) ? ((hash << 7) ^ str.charAt(i) ^ (hash >> 3)) : (~((hash << 11) ^ str.charAt(i) ^ (hash >> 5)));
}
// return (hash & 0x7FFFFFFF);
return hash;
}
/**
* TianL Hash算法
*
* @param str 字符串
* @return Hash值
*/
public static long tianlHash(String str) {
long hash = 0;
int iLength = str.length();
if (iLength == 0) {
return 0;
}
if (iLength <= 256) {
hash = 16777216L * (iLength - 1);
} else {
hash = 4278190080L;
}
int i;
char ucChar;
if (iLength <= 96) {
for (i = 1; i <= iLength; i++) {
ucChar = str.charAt(i - 1);
if (ucChar <= 'Z' && ucChar >= 'A') {
ucChar = (char) (ucChar + 32);
}
hash += (3 * i * ucChar * ucChar + 5 * i * ucChar + 7 * i + 11 * ucChar) % 16777216;
}
} else {
for (i = 1; i <= 96; i++) {
ucChar = str.charAt(i + iLength - 96 - 1);
if (ucChar <= 'Z' && ucChar >= 'A') {
ucChar = (char) (ucChar + 32);
}
hash += (3 * i * ucChar * ucChar + 5 * i * ucChar + 7 * i + 11 * ucChar) % 16777216;
}
}
if (hash < 0) {
hash *= -1;
}
return hash;
}
/**
* JAVA自己带的算法
*
* @param str 字符串
* @return hash值
*/
public static int javaDefaultHash(String str) {
int h = 0;
int off = 0;
int len = str.length();
for (int i = 0; i < len; i++) {
h = 31 * h + str.charAt(off++);
}
return h;
}
/**
* 混合hash算法，输出64位的值
*
* @param str 字符串
* @return hash值
*/
public static long mixHash(String str) {
long hash = str.hashCode();
hash <<= 32;
hash |= fnvHash(str);
return hash;
}
/**
* 根据对象的内存地址生成相应的Hash值
*
* @param obj 对象
* @return hash值
* @since 4.2.2
*/
public static int identityHashCode(Object obj) {
return System.identityHashCode(obj);
}
/**
* MurmurHash算法32-bit实现
*
* @param data 数据
* @return hash值
* @since 4.3.3
*/
public static int murmur32(byte[] data) {
int length = data.length;
int hash = DEFAULT_SEED;
final int nblocks = length >> 2;
// body
for (int i = 0; i < nblocks; i++) {
int i_4 = i << 2;
int k = (data[i_4] & 0xff) //
| ((data[i_4 + 1] & 0xff) << 8) //
| ((data[i_4 + 2] & 0xff) << 16) //
| ((data[i_4 + 3] & 0xff) << 24);
// mix functions
k *= C1_32;
k = Integer.rotateLeft(k, R1_32);
k *= C2_32;
hash ^= k;
hash = Integer.rotateLeft(hash, R2_32) * M_32 + N_32;
}
// tail
int idx = nblocks << 2;
int k1 = 0;
switch (length - idx) {
case 3:
k1 ^= data[idx + 2] << 16;
case 2:
k1 ^= data[idx + 1] << 8;
case 1:
k1 ^= data[idx];
// mix functions
k1 *= C1_32;
k1 = Integer.rotateLeft(k1, R1_32);
k1 *= C2_32;
hash ^= k1;
}
// finalization
hash ^= length;
hash ^= (hash >>> 16);
hash *= 0x85ebca6b;
hash ^= (hash >>> 13);
hash *= 0xc2b2ae35;
hash ^= (hash >>> 16);
return hash;
}
/**
* MurmurHash算法64-bit实现
*
* @param data 数据
* @return hash值
* @since 4.3.3
*/
public static long murmur64(byte[] data) {
return hash64(data);
}
private static long hash64(byte[] data) {
return 0;
}
/**
* MurmurHash算法128-bit实现
*
* @param data 数据
* @return hash值
* @since 4.3.3
*/
public static long[] murmur128(byte[] data) {
return hash128(data);
}
private static long[] hash128(byte[] data) {
return new long[0];
}
}