DFA算法：即确定有穷自动机，简单点说就是，它是是通过event和当前的state得到下一个state，即event+state=nextstate。理解为系统中有多个节点，通过传递进入的event，来确定走哪个路由至另一个节点，而节点是有限的。
废话不多说，直接贴上代码：
import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.InputStreamReader; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.Map; import java.util.Set; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * @description:敏感词工具 * @author: maojialong * @date: 2018年1月30日 上午10:59:24 */ public class SensitivewordEngine { private String ENCODING = "GBK"; //字符编码 //敏感词库 public static Map sensitiveWordMap = new HashMap(); //只过滤最小敏感词 public static int minMatchTYpe = 1; //过滤所有敏感词 public static int maxMatchType = 2; //正则表达式中文、字母、数字 public static Pattern pattern = Pattern.compile("^[a-zA-Z0-9u4E00-u9FA5]+$"); /** * 读取敏感词库中的内容，将内容添加到set集合中 * @author chenming * @date 2014年4月20日 下午2:31:18 * @return * @version 1.0 * @throws Exception */ @SuppressWarnings("resource") private void readSensitiveWordFile() throws Exception{ Set<String> set = null; File file = new File("D:\SensitiveWord.txt"); //读取文件 InputStreamReader read = new InputStreamReader(new FileInputStream(file),ENCODING); try { if(file.isFile() && file.exists()){ //文件流是否存在 set = new HashSet<String>(); BufferedReader bufferedReader = new BufferedReader(read); String txt = null; while((txt = bufferedReader.readLine()) != null){ //读取文件，将文件内容放入到set中 set.add(txt); } } else{ //不存在抛出异常信息 throw new Exception("敏感词库文件不存在"); } } catch (Exception e) { throw e; }finally{ read.close(); //关闭文件流 } addNewSensitiveWord(set); } /** * @description: 新增敏感词库 * @author: maojialong * @date: 2018年2月1日 上午11:55:10 * @param keyWordSet */ public static void addNewSensitiveWord(Set<String> keyWordSet) { sensitiveWordMap.putAll(getNewSensitiveWordToHashMap(keyWordSet)); } /** * @description: 封装敏感词库 * @author: maojialong * @date: 2018年1月30日 下午4:28:58 * @param keyWordSet * @return */ @SuppressWarnings("rawtypes") public static HashMap getNewSensitiveWordToHashMap(Set<String> keyWordSet) { // 初始化HashMap对象并控制容器的大小 HashMap newSensitiveWordMap = new HashMap(keyWordSet.size()); // 敏感词 String key = null; // 用来按照相应的格式保存敏感词库数据 Map nowMap = null; // 用来辅助构建敏感词库 Map<String, String> newWorMap = null; // 使用一个迭代器来循环敏感词集合 Iterator<String> iterator = keyWordSet.iterator(); while (iterator.hasNext()) { key = iterator.next(); // 等于敏感词库，HashMap对象在内存中占用的是同一个地址，所以此nowMap对象的变化，sensitiveWordMap对象也会跟着改变 nowMap = sensitiveWordMap; for (int i = 0; i < key.length(); i++) { // 截取敏感词当中的字，在敏感词库中字为HashMap对象的Key键值 char keyChar = key.charAt(i); //不是汉字数字字母直接跳过 Matcher match = pattern.matcher(String.valueOf(keyChar)); boolean matched = match.matches(); if(!matched) { continue; } // 判断这个字是否存在于敏感词库中 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; } // 如果该字是当前敏感词的最后一个字，则标识为结尾字 if (i == key.length() - 1) { nowMap.put("isEnd", "1"); } } } return newSensitiveWordMap; } /** * @description: 敏感词库敏感词数量 * @author: maojialong * @date: 2018年1月30日 下午4:07:20 * @return */ public static int getWordSize() { if (SensitivewordEngine.sensitiveWordMap == null) { return 0; } return SensitivewordEngine.sensitiveWordMap.size(); } /** * @description: 是否包含敏感词 * @author: maojialong * @date: 2018年1月30日 下午2:47:37 * @param txt * @param matchType * @return */ 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; } /** * @description: 获取敏感词内容 * @author: maojialong * @date: 2018年1月30日 下午2:47:27 * @param txt * @param matchType * @return */ 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) { // 将检测出的敏感词保存到集合中 sensitiveWordList.add(txt.substring(i, i + length)); i = i + length - 1; } } return sensitiveWordList; } /** * @description: 替换敏感词 * @author: maojialong * @date: 2018年1月30日 下午2:47:15 * @param txt * @param matchType * @param replaceChar * @return */ 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()); try { resultTxt = resultTxt.replaceAll(word, replaceString); }catch(Exception e) { } } return resultTxt; } /** * @description: 获取替换字符 * @author: maojialong * @date: 2018年1月30日 下午2:46:40 * @param replaceChar * @param length * @return */ private static String getReplaceChars(String replaceChar, int length) { String resultReplace = replaceChar; for (int i = 1; i < length; i++) { resultReplace += replaceChar; } return resultReplace; } /** * @description: 检查敏感词 * @author: maojialong * @date: 2018年1月30日 下午2:45:50 * @param txt * @param beginIndex * @param matchType * @return */ public static int checkSensitiveWord(String txt, int beginIndex, int matchType) { boolean flag = false; // 记录敏感词数量 int matchFlag = 0; char word = 0; Map nowMap = SensitivewordEngine.sensitiveWordMap; for (int i = beginIndex; i < txt.length(); i++) { word = txt.charAt(i); if(matchFlag > 0 && !flag ) { Matcher match = pattern.matcher(String.valueOf(word)); boolean matched = match.matches(); if(!matched) { matchFlag++; continue; } } // 判断该字是否存在于敏感词库中 nowMap = (Map) nowMap.get(word); if (nowMap != null) { matchFlag++; // 判断是否是敏感词的结尾字，如果是结尾字则判断是否继续检测 if ("1".equals(nowMap.get("isEnd"))) { flag = true; // 判断过滤类型，如果是小过滤则跳出循环，否则继续循环 if (SensitivewordEngine.minMatchTYpe == matchType) { break; } } } else { break; } } if (matchFlag < 2 || !flag) { matchFlag = 0; } return matchFlag; } /** * @description: 删除敏感词 * @author: maojialong * @date: 2018年2月1日 上午11:40:45 * @param keyWord */ public static void removeSensitiveWordToHashMap(String keyWord) { int length = keyWord.length(); Map<Integer,Map> tempMap = new HashMap<Integer,Map>(); char word = 0; boolean flag = false; Map nowMap = sensitiveWordMap; for(int i = 0; i < length ; i++){ word = keyWord.charAt(i); Map lastMap = nowMap; nowMap = (Map) nowMap.get(word); //获取指定key if(nowMap != null){ //存在，则判断是否为最后一个 tempMap.put(i, lastMap); }else{ //不存在，直接返回 break; } if (i == length -1 && "1".equals(nowMap.get("isEnd"))) { flag = true; } } if(flag) { for(int i = length - 1; i >= 0 ; i--){ word = keyWord.charAt(i); nowMap = tempMap.get(i); Map m = (Map) nowMap.get(word); boolean last = m.size() == 1 && "1".equals(m.get("isEnd")) && i == length - 1; boolean notLast = m.size() == 1 && "0".equals(m.get("isEnd")); if(last || notLast) { nowMap.remove(keyWord.charAt(i)); }else { break; } } } } public static void main(String[] args) throws InterruptedException { Set<String> sensitiveWord = new HashSet<String>(); sensitiveWord.add("大娃"); SensitivewordEngine.addNewSensitiveWord(sensitiveWord); String result = SensitivewordEngine.replaceSensitiveWord("我是大娃，我弟弟是大二娃，我们都是葫芦娃", 2,"＊"); System.out.println(result); System.out.println(SensitivewordEngine.sensitiveWordMap); //新增或者批量新增 sensitiveWord.add("大二娃"); sensitiveWord.add("大二"); SensitivewordEngine.addNewSensitiveWord(sensitiveWord); result = SensitivewordEngine.replaceSensitiveWord("我是大娃，我弟弟是大二娃，我们现在读大二，我们都是葫芦娃", 2,"＊"); System.out.println(result); System.out.println(SensitivewordEngine.sensitiveWordMap); //删除 SensitivewordEngine.removeSensitiveWordToHashMap("大二娃"); result = SensitivewordEngine.replaceSensitiveWord("我是大娃，我弟弟是大二娃，我们现在读大二，我们都是葫芦娃", 2,"＊"); System.out.println(result); System.out.println(SensitivewordEngine.sensitiveWordMap); } }
复制代码即可食用，最后的removeSensitiveWordToHashMap是我一个朋友帮忙写的，其他方法时参考网上的其他博文整理的