遇到一个过滤敏感词的需求,根据网上查询的资料整理了一下,代码如下
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;
/**
* 敏感词过滤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; // 最小匹配规则
// private static int maxMatchType = 2; // 最大匹配规则
private String ENCODING = "UTF-8"; // 字符编码
/**
* 构造函数,初始化敏感词库
*/
private SensitivewordFilter() {
this.sensitiveWordMap = initKeyWord();
}
/**
*
* @return
*/
@SuppressWarnings("rawtypes")
private Map initKeyWord() {
try {
// 读取敏感词库
Set<String> keyWordSet = readSensitiveWordFile();
// 将敏感词库加入到HashMap中
addSensitiveWordToHashMap(keyWordSet);
// spring获取application,然后application.setAttribute("sensitiveWordMap",sensitiveWordMap);
} catch (Exception e) {
e.printStackTrace();
}
return sensitiveWordMap;
}
/**
* 读取敏感词库,将敏感词放入HashSet中,构建一个DFA算法模型:<br>
* 中 = { isEnd = 0 国 = {<br>
* isEnd = 1 人 = {isEnd = 0 民 = {isEnd = 1} } 男 = { isEnd = 0 人 = { isEnd =
* 1 } } } } 五 = { isEnd = 0 星 = { isEnd = 0 红 = { isEnd = 0 旗 = { isEnd = 1
* } } } }
*
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
private void addSensitiveWordToHashMap(Set<String> keyWordSet) {
sensitiveWordMap = new HashMap(keyWordSet.size()); // 初始化敏感词容器,减少扩容操作
String key = null;
Map nowMap = null;
Map<String, String> newWorMap = null;
// 迭代keyWordSet
Iterator<String> iterator = keyWordSet.iterator();
while (iterator.hasNext()) {
key = iterator.next(); // 关键字
nowMap = sensitiveWordMap;
for (int i = 0; i < key.length(); i++) {
char keyChar = key.charAt(i); // 转换成char型
Object wordMap = nowMap.get(keyChar); // 获取
if (wordMap != null) { // 如果存在该key,直接赋值
nowMap = (Map) wordMap;
} else { // 不存在则,则构建一个map,同时将isEnd设置为0,因为他不是最后一个
newWorMap = new HashMap<String, String>();
newWorMap.put("isEnd", "0"); // 不是最后一个
nowMap.put(keyChar, newWorMap);
nowMap = newWorMap;
}
if (i == key.length() - 1) {
nowMap.put("isEnd", "1"); // 最后一个
}
}
}
}
/**
* 读取敏感词库中的内容,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); // 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<>();
BufferedReader bufferedReader = new BufferedReader(read);
String txt;
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
}
return set;
}
/**
* 判断文字是否包含敏感字符
*
* @param txt
* 文字
* @param matchType
* 匹配规则 1:最小匹配规则,2:最大匹配规则
* @return 若包含返回true,否则返回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); // 判断是否包含敏感字符
if (matchFlag > 0) { // 大于0存在,返回true
flag = true;
}
}
return flag;
}
/**
* 获取文字中的敏感词
*
* @param txt
* 文字
* @param matchType
* 匹配规则 1:最小匹配规则,2:最大匹配规则
* @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); // 判断是否包含敏感字符
if (length > 0) { // 存在,加入list中
sensitiveWordList.add(txt.substring(i, i + length));
i = i + length - 1; // 减1的原因,是因为for会自增
}
}
return sensitiveWordList;
}
/**
* 替换敏感字字符
*
* @param txt
* @param matchType
* @param replaceChar
* 替换字符,默认*
*/
public String replaceSensitiveWord(String txt, int matchType, String replaceChar) {
String resultTxt = txt;
Set<String> set = getSensitiveWord(txt, matchType); // 获取所有的敏感词
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;
}
/**
* 获取替换字符串
*
* @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;
}
/**
* 检查文字中是否包含敏感字符,检查规则如下:<br>
*
* @param txt
* @param beginIndex
* @param matchType
* @return,如果存在,则返回敏感词字符的长度,不存在返回0
*/
@SuppressWarnings({ "rawtypes" })
public int CheckSensitiveWord(String txt, int beginIndex, int matchType) {
boolean flag = false; // 敏感词结束标识位:用于敏感词只有1位的情况
int matchFlag = 0; // 匹配标识数默认为0
char word = 0;
Map nowMap = sensitiveWordMap;
for (int i = beginIndex; i < txt.length(); i++) {
word = txt.charAt(i);
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
matchFlag++; // 找到相应key,匹配标识+1
if ("1".equals(nowMap.get("isEnd"))) { // 如果为最后一个匹配规则,结束循环,返回匹配标识数
flag = true; // 结束标志位为true
if (SensitivewordFilter.minMatchTYpe == matchType) { // 最小规则,直接返回,最大规则还需继续查找
break;
}
}
} else { // 不存在,直接返回
break;
}
}
if (matchFlag < 2 || !flag) { // 长度必须大于等于1,为词
matchFlag = 0;
}
return matchFlag;
}
/**
* 判断是否含有敏感词
*
* @param word
* @return
*/
public boolean isSensitive(String word) {
Set<String> words = getSensitiveWord(word, 1);
return words != null && words.size() > 0;
}
}