mirror of
https://gitee.com/chinabugotech/hutool.git
synced 2025-04-19 03:01:48 +08:00
feat:基于AC自动机算法实现的高效替换器
This commit is contained in:
kyao
parent
07de6aa4f0
commit
a53e994a84
@ -0,0 +1,212 @@
|
||||
/*
|
||||
* Copyright (c) 2023 looly(loolly@aliyun.com)
|
||||
* Hutool is licensed under Mulan PSL v2.
|
||||
* You can use this software according to the terms and conditions of the Mulan PSL v2.
|
||||
* You may obtain a copy of Mulan PSL v2 at:
|
||||
* https://license.coscl.org.cn/MulanPSL2
|
||||
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
|
||||
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
|
||||
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
|
||||
* See the Mulan PSL v2 for more details.
|
||||
*/
|
||||
|
||||
package org.dromara.hutool.core.text.replacer;
|
||||
|
||||
import java.util.HashMap;
|
||||
import java.util.LinkedList;
|
||||
import java.util.Map;
|
||||
|
||||
/**
|
||||
* 高效替换器，通过查找指定关键字，替换对应的值
|
||||
* 基于AC自动机算法实现，需要被替换的原字符串越大，替换的键值对越多，效率提升越明显
|
||||
* <p>
|
||||
* 注意: 如果需要被替换的关键字出现交叉,最先匹配中的关键字会被替换
|
||||
* 1、"abc","ab" 会优先替换"ab"
|
||||
* 2、"abed","be" 会优先替换"abed"
|
||||
* 3、"abc", "bc" 会优先替换"abc"
|
||||
*
|
||||
* @author kyao
|
||||
*/
|
||||
public class HighMultiReplacer extends StrReplacer {
|
||||
|
||||
private final AhoCorasickAutomaton ahoCorasickAutomaton;
|
||||
|
||||
/**
|
||||
* 构造
|
||||
*
|
||||
* @param map key为需要被查找的字符串，value为对应的替换的值
|
||||
*/
|
||||
public HighMultiReplacer(Map<String, String> map) {
|
||||
ahoCorasickAutomaton = new AhoCorasickAutomaton(map);
|
||||
}
|
||||
|
||||
/**
|
||||
* 生成一个HighMultiReplacer对象
|
||||
*
|
||||
* @param map key为需要被查找的字符串，value为对应的替换的值
|
||||
* @return org.dromara.hutool.core.text.replacer.HighMultiReplacer
|
||||
*/
|
||||
public static HighMultiReplacer of(Map<String, String> map) {
|
||||
return new HighMultiReplacer(map);
|
||||
}
|
||||
|
||||
@Override
|
||||
protected int replace(CharSequence str, int pos, StringBuilder out) {
|
||||
ahoCorasickAutomaton.replace(str, out);
|
||||
return str.length();
|
||||
}
|
||||
|
||||
@Override
|
||||
public CharSequence apply(final CharSequence str) {
|
||||
StringBuilder builder = new StringBuilder();
|
||||
replace(str, 0, builder);
|
||||
return builder;
|
||||
}
|
||||
|
||||
/**
|
||||
* AC自动机
|
||||
*/
|
||||
private static class AhoCorasickAutomaton {
|
||||
|
||||
/*AC自动机的根结点，根结点不存储任何字符信息*/
|
||||
private final Node root;
|
||||
|
||||
/*待查找的目标字符串集合*/
|
||||
private final Map<String, String> target;
|
||||
|
||||
/**
|
||||
* @param target 待查找的目标字符串集合
|
||||
*/
|
||||
public AhoCorasickAutomaton(Map<String, String> target) {
|
||||
root = new Node();
|
||||
this.target = target;
|
||||
buildTrieTree();
|
||||
buildAcFromTrie();
|
||||
}
|
||||
|
||||
/**
|
||||
* 用于表示AC自动机的每个结点，在每个结点中我们并没有存储该结点对应的字符
|
||||
*/
|
||||
private static class Node {
|
||||
|
||||
/*如果该结点是一个终点，即，从根结点到此结点表示了一个目标字符串，则str != null, 且str就表示该字符串*/
|
||||
String str;
|
||||
|
||||
/*该节点下的子节点*/
|
||||
Map<Character, Node> children = new HashMap<>();
|
||||
|
||||
/*当前结点的孩子结点不能匹配文本串中的某个字符时，下一个应该查找的结点*/
|
||||
Node fail;
|
||||
|
||||
public boolean isWord() {
|
||||
return str != null;
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* 由目标字符串构建Trie树
|
||||
*/
|
||||
private void buildTrieTree() {
|
||||
for (String targetStr : target.keySet()) {
|
||||
Node curr = root;
|
||||
if (targetStr == null) {
|
||||
continue;
|
||||
}
|
||||
for (int i = 0; i < targetStr.length(); i++) {
|
||||
char ch = targetStr.charAt(i);
|
||||
Node node = curr.children.get(ch);
|
||||
if (node == null) {
|
||||
node = new Node();
|
||||
curr.children.put(ch, node);
|
||||
}
|
||||
curr = node;
|
||||
}
|
||||
/*将每个目标字符串的最后一个字符对应的结点变成终点*/
|
||||
curr.str = targetStr;
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* 由Trie树构建AC自动机，本质是一个自动机，相当于构建KMP算法的next数组
|
||||
*/
|
||||
private void buildAcFromTrie() {
|
||||
/*广度优先遍历所使用的队列*/
|
||||
LinkedList<Node> queue = new LinkedList<>();
|
||||
|
||||
/*单独处理根结点的所有孩子结点*/
|
||||
for (Node x : root.children.values()) {
|
||||
/*根结点的所有孩子结点的fail都指向根结点*/
|
||||
x.fail = root;
|
||||
queue.addLast(x);/*所有根结点的孩子结点入列*/
|
||||
}
|
||||
|
||||
while (!queue.isEmpty()) {
|
||||
/*确定出列结点的所有孩子结点的fail的指向*/
|
||||
Node p = queue.removeFirst();
|
||||
for (Map.Entry<Character, Node> entry : p.children.entrySet()) {
|
||||
|
||||
/*孩子结点入列*/
|
||||
queue.addLast(entry.getValue());
|
||||
/*从p.fail开始找起*/
|
||||
Node failTo = p.fail;
|
||||
while (true) {
|
||||
/*说明找到了根结点还没有找到*/
|
||||
if (failTo == null) {
|
||||
entry.getValue().fail = root;
|
||||
break;
|
||||
}
|
||||
|
||||
/*说明有公共前缀*/
|
||||
if (failTo.children.get(entry.getKey()) != null) {
|
||||
entry.getValue().fail = failTo.children.get(entry.getKey());
|
||||
break;
|
||||
} else {/*继续向上寻找*/
|
||||
failTo = failTo.fail;
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* 在文本串中替换所有的目标字符串
|
||||
*
|
||||
* @param text 被替换的目标字符串
|
||||
* @param stringBuilder 替换后的结果
|
||||
*/
|
||||
public void replace(CharSequence text, StringBuilder stringBuilder) {
|
||||
Node curr = root;
|
||||
int i = 0;
|
||||
while (i < text.length()) {
|
||||
/*文本串中的字符*/
|
||||
char ch = text.charAt(i);
|
||||
/*文本串中的字符和AC自动机中的字符进行比较*/
|
||||
Node node = curr.children.get(ch);
|
||||
if (node != null) {
|
||||
stringBuilder.append(ch);
|
||||
/*若相等，自动机进入下一状态*/
|
||||
curr = node;
|
||||
if (curr.isWord()) {
|
||||
stringBuilder.delete(stringBuilder.length() - curr.str.length(), stringBuilder.length());
|
||||
stringBuilder.append(target.get(curr.str));
|
||||
curr = root;
|
||||
}
|
||||
/*索引自增，指向下一个文本串中的字符*/
|
||||
i++;
|
||||
} else {
|
||||
/*若不等，找到下一个应该比较的状态*/
|
||||
curr = curr.fail;
|
||||
/*到根结点还未找到，说明文本串中以ch作为结束的字符片段不是任何目标字符串的前缀，状态机重置，比较下一个字符*/
|
||||
if (curr == null) {
|
||||
stringBuilder.append(ch);
|
||||
curr = root;
|
||||
i++;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
@ -0,0 +1,32 @@
|
||||
package org.dromara.hutool.core.text.replacer;
|
||||
|
||||
import org.junit.jupiter.api.Assertions;
|
||||
import org.junit.jupiter.api.Test;
|
||||
|
||||
import java.util.HashMap;
|
||||
import java.util.Map;
|
||||
|
||||
public class HighMultiReplacerTest {
|
||||
|
||||
@Test
|
||||
public void replaceTest() {
|
||||
Map<String, String> map = new HashMap<>();
|
||||
map.put("abc", "bar");
|
||||
map.put("123", "1234");
|
||||
map.put("12", "哈哈哈");
|
||||
map.put("bc", "67868");
|
||||
map.put("你好", "hello world");
|
||||
map.put("AAACC", "%^$%$");
|
||||
map.put("_啊", "qqqq");
|
||||
HighMultiReplacer replacer = HighMultiReplacer.of(map);
|
||||
Assertions.assertEquals("bar哈哈哈hello world4", replacer.apply("abc12你好4").toString());
|
||||
Assertions.assertEquals("qqqq啊qqqq-啊", replacer.apply("_啊啊_啊-啊").toString());
|
||||
Assertions.assertEquals("哈哈哈3456789", replacer.apply("123456789").toString());
|
||||
Assertions.assertEquals("AAAC67868", replacer.apply("AAACbc").toString());
|
||||
Assertions.assertEquals("哈哈哈哈哈1哈哈", replacer.apply("哈哈121哈哈").toString());
|
||||
Assertions.assertEquals("你hello world好%^$%$CACAC", replacer.apply("你你好好AAACCCACAC").toString());
|
||||
Assertions.assertEquals("哈哈哈3", replacer.apply("123").toString());
|
||||
Assertions.assertEquals("---11", replacer.apply("---11").toString());
|
||||
Assertions.assertEquals("", replacer.apply("").toString());
|
||||
}
|
||||
}
|
||||
Loading…
x
Reference in New Issue
Block a user