遇到一個過濾敏感詞的需求,根據網上查詢的資料整理了一下,代碼如下
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 org.springframework.stereotype.Component;
/**
* 敏感詞過濾bean
*
* @author zhanchong
* @email [email protected]
* @date 2019-02-21 13:14:51
*/
@Component
public class SensitivewordFilter {
@SuppressWarnings("rawtypes")
private Map sensitiveWordMap = null;
private static int minMatchTYpe = 1; // 最小比對規則
// private static int maxMatchType = 2; // 最大比對規則
private String ENCODING = "UTF-8"; // 字元編碼
/**
* 構造函數,初始化敏感詞庫
*/
private SensitivewordFilter() {
this.sensitiveWordMap = initKeyWord();
}
/**
*
* @return
*/
@SuppressWarnings("rawtypes")
private Map initKeyWord() {
try {
// 讀取敏感詞庫
Set<String> keyWordSet = readSensitiveWordFile();
// 将敏感詞庫加入到HashMap中
addSensitiveWordToHashMap(keyWordSet);
// spring擷取application,然後application.setAttribute("sensitiveWordMap",sensitiveWordMap);
} catch (Exception e) {
e.printStackTrace();
}
return sensitiveWordMap;
}
/**
* 讀取敏感詞庫,将敏感詞放入HashSet中,建構一個DFA算法模型:<br>
* 中 = { isEnd = 0 國 = {<br>
* isEnd = 1 人 = {isEnd = 0 民 = {isEnd = 1} } 男 = { isEnd = 0 人 = { isEnd =
* 1 } } } } 五 = { isEnd = 0 星 = { isEnd = 0 紅 = { isEnd = 0 旗 = { isEnd = 1
* } } } }
*
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
private void addSensitiveWordToHashMap(Set<String> keyWordSet) {
sensitiveWordMap = new HashMap(keyWordSet.size()); // 初始化敏感詞容器,減少擴容操作
String key = null;
Map nowMap = null;
Map<String, String> newWorMap = null;
// 疊代keyWordSet
Iterator<String> iterator = keyWordSet.iterator();
while (iterator.hasNext()) {
key = iterator.next(); // 關鍵字
nowMap = sensitiveWordMap;
for (int i = 0; i < key.length(); i++) {
char keyChar = key.charAt(i); // 轉換成char型
Object wordMap = nowMap.get(keyChar); // 擷取
if (wordMap != null) { // 如果存在該key,直接指派
nowMap = (Map) wordMap;
} else { // 不存在則,則建構一個map,同時将isEnd設定為0,因為他不是最後一個
newWorMap = new HashMap<String, String>();
newWorMap.put("isEnd", "0"); // 不是最後一個
nowMap.put(keyChar, newWorMap);
nowMap = newWorMap;
}
if (i == key.length() - 1) {
nowMap.put("isEnd", "1"); // 最後一個
}
}
}
}
/**
* 讀取敏感詞庫中的内容,将内容添加到set集合中
*
* @return
* @throws Exception
*/
@SuppressWarnings("resource")
private Set<String> readSensitiveWordFile() throws Exception {
Set<String> set = null;
String url = SensitivewordFilter.class.getResource("/key.txt").getFile();
File file = new File(url); // 讀取檔案
InputStreamReader read = new InputStreamReader(new FileInputStream(file), ENCODING);
try {
if (file.isFile() && file.exists()) { // 檔案流是否存在
set = new HashSet<>();
BufferedReader bufferedReader = new BufferedReader(read);
String txt;
while ((txt = bufferedReader.readLine()) != null) { // 讀取檔案,将檔案内容放入到set中
set.add(txt);
}
} else { // 不存在抛出異常資訊
throw new Exception("敏感詞庫檔案不存在");
}
} catch (Exception e) {
throw e;
} finally {
read.close(); // 關閉檔案流
}
return set;
}
/**
* 判斷文字是否包含敏感字元
*
* @param txt
* 文字
* @param matchType
* 比對規則 1:最小比對規則,2:最大比對規則
* @return 若包含傳回true,否則傳回false
*/
public boolean isContaintSensitiveWord(String txt, int matchType) {
boolean flag = false;
for (int i = 0; i < txt.length(); i++) {
int matchFlag = this.CheckSensitiveWord(txt, i, matchType); // 判斷是否包含敏感字元
if (matchFlag > 0) { // 大于0存在,傳回true
flag = true;
}
}
return flag;
}
/**
* 擷取文字中的敏感詞
*
* @param txt
* 文字
* @param matchType
* 比對規則 1:最小比對規則,2:最大比對規則
* @return
*/
public Set<String> getSensitiveWord(String txt, int matchType) {
Set<String> sensitiveWordList = new HashSet<>();
for (int i = 0; i < txt.length(); i++) {
int length = CheckSensitiveWord(txt, i, matchType); // 判斷是否包含敏感字元
if (length > 0) { // 存在,加入list中
sensitiveWordList.add(txt.substring(i, i + length));
i = i + length - 1; // 減1的原因,是因為for會自增
}
}
return sensitiveWordList;
}
/**
* 替換敏感字字元
*
* @param txt
* @param matchType
* @param replaceChar
* 替換字元,預設*
*/
public String replaceSensitiveWord(String txt, int matchType, String replaceChar) {
String resultTxt = txt;
Set<String> set = getSensitiveWord(txt, matchType); // 擷取所有的敏感詞
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;
}
/**
* 擷取替換字元串
*
* @param replaceChar
* @param length
* @return
*/
public String getReplaceChars(String replaceChar, int length) {
String resultReplace = replaceChar;
for (int i = 1; i < length; i++) {
resultReplace += replaceChar;
}
return resultReplace;
}
/**
* 檢查文字中是否包含敏感字元,檢查規則如下:<br>
*
* @param txt
* @param beginIndex
* @param matchType
* @return,如果存在,則傳回敏感詞字元的長度,不存在傳回0
*/
@SuppressWarnings({ "rawtypes" })
public int CheckSensitiveWord(String txt, int beginIndex, int matchType) {
boolean flag = false; // 敏感詞結束辨別位:用于敏感詞隻有1位的情況
int matchFlag = 0; // 比對辨別數預設為0
char word = 0;
Map nowMap = sensitiveWordMap;
for (int i = beginIndex; i < txt.length(); i++) {
word = txt.charAt(i);
nowMap = (Map) nowMap.get(word); // 擷取指定key
if (nowMap != null) { // 存在,則判斷是否為最後一個
matchFlag++; // 找到相應key,比對辨別+1
if ("1".equals(nowMap.get("isEnd"))) { // 如果為最後一個比對規則,結束循環,傳回比對辨別數
flag = true; // 結束标志位為true
if (SensitivewordFilter.minMatchTYpe == matchType) { // 最小規則,直接傳回,最大規則還需繼續查找
break;
}
}
} else { // 不存在,直接傳回
break;
}
}
if (matchFlag < 2 || !flag) { // 長度必須大于等于1,為詞
matchFlag = 0;
}
return matchFlag;
}
/**
* 判斷是否含有敏感詞
*
* @param word
* @return
*/
public boolean isSensitive(String word) {
Set<String> words = getSensitiveWord(word, 1);
return words != null && words.size() > 0;
}
}