java 實現DFA 算法（理論百度搜索）
阿新 • • 發佈：2019-05-09
value orm shm match tco val ltr 實體 ash DFA簡介
DFA全稱為：Deterministic Finite Automaton,即確定有窮自動機。（自己百度吧）
直接代碼：
敏感詞實體類
package com.nopsmile.dfa; public class Keywords { private String pid; private String Content; public Keywords() { } public Keywords(String content) { super(); Content = content; } public String getContent() { return Content; } public void setContent(String content) { Content = content; } public String getPid() { return pid; } public void setPid(String pid) { this.pid = pid; } }
敏感詞庫初始化
package com.nopsmile.dfa; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Set; /** * 敏感詞庫初始化 * */ public class SensitiveWordInit{ /** * 敏感詞庫 */ public HashMap sensitiveWordMap; /** * 初始化敏感詞 keywords */ public Map initKeyWord(List<Keywords> sensitiveWords) { try { // 從敏感詞集合對象中取出敏感詞並封裝到Set集合中 Set<String> keyWordSet = new HashSet<String>(); for (Keywords s : sensitiveWords) { keyWordSet.add(s.getContent().trim()); } // 將敏感詞庫加入到HashMap中 addSensitiveWordToHashMap(keyWordSet); } catch (Exception e) { e.printStackTrace(); } return sensitiveWordMap; } /** * 封裝敏感詞庫 */ private void addSensitiveWordToHashMap(Set<String> keyWordSet) { // 初始化HashMap對象並控制容器的大小 sensitiveWordMap = new HashMap(keyWordSet.size()); // 敏感詞 String key = null; // 用來按照相應的格式保存敏感詞庫數據 Map nowMap = null; // 用來輔助構建敏感詞庫 Map<String, String> newWorMap = null; // 使用一個叠代器來循環敏感詞集合 Iterator<String> iterator = keyWordSet.iterator(); while (iterator.hasNext()) { key = iterator.next(); // 等於敏感詞庫，HashMap對象在內存中占用的是同一個地址，所以此nowMap對象的變化，sensitiveWordMap對象也會跟著改變 nowMap = sensitiveWordMap; for (int i = 0; i < key.length(); i++) { // 截取敏感詞當中的字，在敏感詞庫中字為HashMap對象的Key鍵值 char keyChar = key.charAt(i); // 判斷這個字是否存在於敏感詞庫中 Object wordMap = nowMap.get(keyChar); if (wordMap != null) { nowMap = (Map) wordMap; } else { newWorMap = new HashMap<String, String>(); newWorMap.put("isEnd", "0"); nowMap.put(keyChar, newWorMap); nowMap = newWorMap; } // 如果該字是當前敏感詞的最後一個字，則標識為結尾字 if (i == key.length() - 1) { nowMap.put("isEnd", "1"); } } } } }
自定義的工具類
package com.nopsmile.dfa; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; import com.alibaba.fastjson.JSONArray; import net.sf.json.JSONObject; /** * 敏感詞過濾工具類 * * @author AlanLee * */ public class SensitivewordUtils { /** * 敏感詞庫 */ public static Map sensitiveWordMap = null; /** * 只過濾最小敏感詞 */ public static int minMatchTYpe = 1; /** * 過濾所有敏感詞 */ public static int maxMatchType = 2; /** * 敏感詞庫敏感詞數量 * * @return */ public static int getWordSize() { if (SensitivewordUtils.sensitiveWordMap == null) { return 0; } return SensitivewordUtils.sensitiveWordMap.size(); } /** * 是否包含敏感詞 * */ public static boolean isContaintSensitiveWord(String txt, int matchType) { boolean flag = false; for (int i = 0; i < txt.length(); i++) { int matchFlag = checkSensitiveWord(txt, i, matchType); if (matchFlag > 0) { flag = true; } } return flag; } /** * 獲取敏感詞內容 * * @param txt * @param matchType * @return 敏感詞內容 */ public static Set<String> getSensitiveWord(String txt, int matchType) { Set<String> sensitiveWordList = new HashSet<String>(); for (int i = 0; i < txt.length(); i++) { int length = checkSensitiveWord(txt, i, matchType); if (length > 0) { // 將檢測出的敏感詞保存到集合中 sensitiveWordList.add(txt.substring(i, i + length)); i = i + length - 1; } } return sensitiveWordList; } /** * 替換敏感詞 * */ public static String replaceSensitiveWord(String txt, int matchType, String replaceChar) { String resultTxt = txt; Set<String> set = getSensitiveWord(txt, matchType); Iterator<String> iterator = set.iterator(); String word = null; String replaceString = null; while (iterator.hasNext()) { word = iterator.next(); replaceString = getReplaceChars(replaceChar, word.length()); resultTxt = resultTxt.replaceAll(word, replaceString); } return resultTxt; } /** * 替換敏感詞內容 * */ private static String getReplaceChars(String replaceChar, int length) { String resultReplace = replaceChar; for (int i = 1; i < length; i++) { resultReplace += replaceChar; } return resultReplace; } /** * 檢查敏感詞數量 * */ public static int checkSensitiveWord(String txt, int beginIndex, int matchType) { boolean flag = false; // 記錄敏感詞數量 int matchFlag = 0; char word = 0; Map nowMap = SensitivewordUtils.sensitiveWordMap; for (int i = beginIndex; i < txt.length(); i++) { word = txt.charAt(i); // 判斷該字是否存在於敏感詞庫中 nowMap = (Map) nowMap.get(word); if (nowMap != null) { matchFlag++; // 判斷是否是敏感詞的結尾字，如果是結尾字則判斷是否繼續檢測 if ("1".equals(nowMap.get("isEnd"))) { flag = true; // 判斷過濾類型，如果是小過濾則跳出循環，否則繼續循環 if (SensitivewordUtils.minMatchTYpe == matchType) { break; } } } else { break; } } if (!flag) { matchFlag = 0; } return matchFlag; } /** * 敏感詞匯對應個數 * 返回 "關鍵字"="關鍵字個數" * */ public static Map getSensitiveWordSum(String txt, int matchType) { Map<String,Integer> map = new HashMap<String,Integer>(); for (int i = 0; i < txt.length(); i++) { int length = checkSensitiveWord(txt, i, matchType); if (length > 0) { // 將檢測出的敏感詞保存到集合中 String str=txt.substring(i, i + length); if(map.containsKey(str)) { map.put(str, map.get(str).intValue()+1); }else { map.put(str, new Integer(1)); } //System.out.println(txt.substring(i, i + length)); i = i + length - 1; } } return map; } /** * 對map數組value排序，並取前10 * this method will always sort the map; * isCondition is true condition can be used otherwise invalid * @param unsortMap * @return */ public static Map<String, Integer> sortByValue(Map<String, Integer> unsortMap,int condition,boolean isCondition) { // 1. Convert Map to List of Map List<Map.Entry<String, Integer>> list = new LinkedList<Map.Entry<String, Integer>>(unsortMap.entrySet()); // 2. Sort list with Collections.sort(), provide a custom Comparator // Try switch the o1 o2 position for a different order Collections.sort(list, new Comparator<Map.Entry<String, Integer>>() { public int compare(Map.Entry<String, Integer> o1, Map.Entry<String, Integer> o2) { return (o2.getValue()).compareTo(o1.getValue()); } }); // 3. Loop the sorted list and put it into a new insertion order Map LinkedHashMap Map<String, Integer> sortedMap = new LinkedHashMap<String, Integer>(); if(isCondition) { for (int i = 0; i < list.size(); i++) { if (i < condition) { sortedMap.put(list.get(i).getKey(), list.get(i).getValue()); } } }else{ for (int i = 0; i < list.size(); i++) { sortedMap.put(list.get(i).getKey(), list.get(i).getValue()); } } return sortedMap; } }
使用上面類流程代碼
Keywords ss=new Keywords("好");
List list = new ArrayList();
list.add(ss);
SensitiveWordInit sensitiveWordInit = new SensitiveWordInit();
Map sensitiveWordMap = sensitiveWordInit.initKeyWord(list);
// 傳入SensitivewordEngine類中的敏感詞庫
SensitivewordUtils.sensitiveWordMap = sensitiveWordMap;
SensitivewordUtils.getSensitiveWordSum("需要檢測的文本", 2) ；
java 實現DFA 算法（理論百度搜索）