org.aoju.bus.sensitive.WordTree Maven / Gradle / Ivy
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* The MIT License (MIT) *
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* Copyright (c) 2015-2020 aoju.org and other contributors. *
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package org.aoju.bus.sensitive;
import org.aoju.bus.core.lang.Filter;
import org.aoju.bus.core.text.Builders;
import org.aoju.bus.core.toolkit.CollKit;
import org.aoju.bus.core.toolkit.StringKit;
import java.util.*;
/**
* DFA（Deterministic Finite Automaton 确定有穷自动机）
* DFA单词树（以下简称单词树），常用于在某大段文字中快速查找某几个关键词是否存在
* 单词树使用group区分不同的关键字集合，不同的分组可以共享树枝，避免重复建树
* 单词树使用树状结构表示一组单词
*
* @author Kimi Liu
* @version 6.1.3
* @since JDK 1.8+
*/
public class WordTree extends HashMap {
private static final long serialVersionUID = -1L;
/**
* 敏感词字符末尾标识，用于标识单词末尾字符
*/
private final Set endCharacterSet = new HashSet<>();
/**
* 字符过滤规则，通过定义字符串过滤规则，过滤不需要的字符，当accept为false时，此字符不参与匹配
*/
private Filter charFilter = StopChar::isNotStopChar;
/**
* 默认构造
*/
public WordTree() {
}
/**
* 设置字符过滤规则，通过定义字符串过滤规则，过滤不需要的字符
* 当accept为false时，此字符不参与匹配
*
* @param charFilter 过滤函数
* @return this
*/
public WordTree setCharFilter(Filter charFilter) {
this.charFilter = charFilter;
return this;
}
/**
* 增加一组单词
*
* @param words 单词集合
*/
public void addWords(Collection words) {
if (false == (words instanceof Set)) {
words = new HashSet<>(words);
}
for (String word : words) {
addWord(word);
}
}
/**
* 增加一组单词
*
* @param words 单词数组
*/
public void addWords(String... words) {
HashSet wordsSet = CollKit.newHashSet(words);
for (String word : wordsSet) {
addWord(word);
}
}
/**
* 添加单词，使用默认类型
*
* @param word 单词
*/
public void addWord(String word) {
final Filter charFilter = this.charFilter;
WordTree parent = null;
WordTree current = this;
WordTree child;
char currentChar = 0;
int length = word.length();
for (int i = 0; i < length; i++) {
currentChar = word.charAt(i);
if (charFilter.accept(currentChar)) {//只处理合法字符
child = current.get(currentChar);
if (child == null) {
// 无子类，新建一个子节点后存放下一个字符
child = new WordTree();
current.put(currentChar, child);
}
parent = current;
current = child;
}
}
if (null != parent) {
parent.setEnd(currentChar);
}
}
/**
* 指定文本是否包含树中的词
*
* @param text 被检查的文本
* @return 是否包含
*/
public boolean isMatch(String text) {
if (null == text) {
return false;
}
return null != match(text);
}
/**
* 获得第一个匹配的关键字
*
* @param text 被检查的文本
* @return 匹配到的关键字
*/
public String match(String text) {
if (null == text) {
return null;
}
List matchAll = matchAll(text, 1);
if (CollKit.isNotEmpty(matchAll)) {
return matchAll.get(0);
}
return null;
}
/**
* 找出所有匹配的关键字
*
* @param text 被检查的文本
* @return 匹配的词列表
*/
public List matchAll(String text) {
return matchAll(text, -1);
}
/**
* 找出所有匹配的关键字
*
* @param text 被检查的文本
* @param limit 限制匹配个数
* @return 匹配的词列表
*/
public List matchAll(String text, int limit) {
return matchAll(text, limit, false, false);
}
/**
* 找出所有匹配的关键字
* 密集匹配原则：假如关键词有 ab,b，文本是abab，将匹配 [ab,b,ab]
* 贪婪匹配（最长匹配）原则：假如关键字a,ab，最长匹配将匹配[a, ab]
*
* @param text 被检查的文本
* @param limit 限制匹配个数
* @param isDensityMatch 是否使用密集匹配原则
* @param isGreedMatch 是否使用贪婪匹配（最长匹配）原则
* @return 匹配的词列表
*/
public List matchAll(String text, int limit, boolean isDensityMatch, boolean isGreedMatch) {
if (null == text) {
return null;
}
List foundWords = new ArrayList<>();
WordTree current = this;
int length = text.length();
final Filter charFilter = this.charFilter;
// 存放查找到的字符缓存。完整出现一个词时加到findedWords中，否则清空
final Builders wordBuffer = StringKit.builders();
char currentChar;
for (int i = 0; i < length; i++) {
wordBuffer.reset();
for (int j = i; j < length; j++) {
currentChar = text.charAt(j);
if (false == charFilter.accept(currentChar)) {
if (wordBuffer.length() > 0) {
// 做为关键词中间的停顿词被当作关键词的一部分被返回
wordBuffer.append(currentChar);
} else {
// 停顿词做为关键词的第一个字符时需要跳过
i++;
}
continue;
} else if (false == current.containsKey(currentChar)) {
// 非关键字符被整体略过，重新以下个字符开始检查
break;
}
wordBuffer.append(currentChar);
if (current.isEnd(currentChar)) {
// 到达单词末尾，关键词成立，从此词的下一个位置开始查找
foundWords.add(wordBuffer.toString());
if (limit > 0 && foundWords.size() >= limit) {
// 超过匹配限制个数，直接返回
return foundWords;
}
if (false == isDensityMatch) {
// 如果非密度匹配，跳过匹配到的词
i = j;
}
if (false == isGreedMatch) {
// 如果懒惰匹配（非贪婪匹配）。当遇到第一个结尾标记就结束本轮匹配
break;
}
}
current = current.get(currentChar);
if (null == current) {
break;
}
}
current = this;
}
return foundWords;
}
/**
* 是否末尾
*
* @param c 检查的字符
* @return 是否末尾
*/
private boolean isEnd(Character c) {
return this.endCharacterSet.contains(c);
}
/**
* 设置是否到达末尾
*
* @param c 设置结尾的字符
*/
private void setEnd(Character c) {
if (null != c) {
this.endCharacterSet.add(c);
}
}
}
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