【全程干货】程序员必备算法！AC自动机算法敏感词匹配算法！动画演示讲解，看完轻松掌握，面试官都被你唬住！！_哔哩哔哩_bilibili

著名的多模匹配算法

引入依赖：

    org.ahocorasick    ahocorasick    0.6.3 

public List findKeywordsInText(String text, List keywords) {    Trie trie = Trie.builder()          .addKeywords(keywords)          .build();      long start = System.currentTimeMillis();    Collection emits = trie.parseText(text);    logger.info("trie: " + (System.currentTimeMillis() - start));      List matchedKeywords = new ArrayList<>();    for (Emit emit : emits) {       matchedKeywords.add(emit.getKeyword());    }      return matchedKeywords; }

main demo

public static void main(String[] args) {    String BASE_URL = "https://www.baidu.com/s?wd=";      String text = "abcd";    List wordList = new ArrayList<>();    wordList.add("ab");    wordList.add("bc");    wordList.add("cd");    wordList.add("a");    wordList.add("bcd");    wordList.add("abc");      // 构建 Trie 时忽略大小写  Trie trie = Trie.builder()          .ignoreCase()          .addKeywords(wordList)          .build();      Collection emits = trie.parseText(text);      // 按照关键词长度降序排序  List sortedEmits = new ArrayList<>(emits);    sortedEmits.sort((e1, e2) -> e2.getKeyword().length() - e1.getKeyword().length());      // 移除开始位置在前面词的开始和结束中间的关键词  Set processedKeywords = new HashSet<>();    List filteredEmits = new ArrayList<>();    for (Emit emit : sortedEmits) {       String keyword = emit.getKeyword();       boolean shouldAdd = true;       for (Emit filteredEmit : filteredEmits) {          if (emit.getStart() >= filteredEmit.getStart() && emit.getStart() <= filteredEmit.getEnd()) {             shouldAdd = false;             break;          }       }       if (shouldAdd) {          filteredEmits.add(emit);          processedKeywords.add(keyword);       }    }      // 使用TreeMap来保持emit的start位置顺序  TreeMap firstOccurrences = new TreeMap<>();    for (Emit emit : filteredEmits) {       firstOccurrences.putIfAbsent(emit.getStart(), emit);    }      StringBuilder result = new StringBuilder(text);    int offset = 0;    processedKeywords.clear();    for (Emit emit : firstOccurrences.values()) {       String keyword = emit.getKeyword();       if (!processedKeywords.contains(keyword)) {          int startIndex = emit.getStart() + offset;          int endIndex = emit.getEnd() + 1 + offset;          String link = "" + keyword + "";          result.replace(startIndex, endIndex, link);          offset += link.length() - keyword.length();          processedKeywords.add(keyword);       }    }    System.out.println(result.toString()); }