敏感词汇过滤(不区分大小写)

最近项目中,用户评论内容需要屏蔽敏感词汇,从网上总结以下方法,(不区分大小写,如想设置大小写敏感,可以把代码中content..toLowerCase()去掉).具体看代码:

1.读取敏感词汇文档

<span style="font-size:18px;">package com.blemall.wizlife.util.sensitive;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

/**
 * @Description: 初始化敏感词库，将敏感词加入到HashMap中，构建DFA算法模型
 * @Project：test
 * @version 1.0
 */
public class SensitiveWordInit {
	private String ENCODING = "UTF-8";    //字符编码
	@SuppressWarnings("rawtypes")
	public HashMap sensitiveWordMap;

	public SensitiveWordInit(){
		super();
	}

	@SuppressWarnings("rawtypes")
	public 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
	 *                  }
	 *              }
	 *      	}
	 *      }
	 * @param keyWordSet  敏感词库
	 * @version 1.0
	 */
	@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
	 * @author chenming
	 * @date 2014年4月20日 下午2:31:18
	 * @return
	 * @version 1.0
	 * @throws Exception
	 */
	@SuppressWarnings("resource")
	private Set<String> readSensitiveWordFile() throws Exception{
		Set<String> set = null;
		ClassLoader loader=SensitiveWordInit.class.getClassLoader();
		URL url=loader.getResource("/SensitiveWord.txt");
		String filePath =url.getPath();
		File file=new File(filePath);
		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
		}
		return set;
	}
}
</span>

2.具体方法:

replaceSensitiveWord(String content(内容),int matchType(匹配规则),String replaceChar(替换词))

<span style="font-size:18px;">package com.blemall.wizlife.util.sensitive;

import org.springframework.stereotype.Component;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

@Component
public class SensitivewordFilter {
	@SuppressWarnings("rawtypes")
	private Map sensitiveWordMap = null;
	public static int minMatchTYpe = 1;      //最小匹配规则
	public static int maxMatchType = 2;      //最大匹配规则

	/**
	 * 构造函数，初始化敏感词库
	 */
	public SensitivewordFilter(){
		sensitiveWordMap = new SensitiveWordInit().initKeyWord();
	}

	/**
	 * 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
	 * @version 1.0
	 */
	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
	 * @version 1.0
	 */
	public 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);    //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;
	}

	/**
	 * @date 2014年4月20日 下午5:12:07
	 * @param content
	 * @param matchType
	 * @param replaceChar 替换字符，默认*
	 * @version 1.0
	 */
	public String replaceSensitiveWord(String content,int matchType,String replaceChar){
		String resultTxt = content;
		Set<String> set = getSensitiveWord(content.toLowerCase(), matchType);//将输入内容先转换为小写,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();
			word="(?i)"+word;
			replaceString = getReplaceChars(replaceChar, word.length());
			resultTxt = resultTxt.replaceAll(word, replaceString);
		}
		return resultTxt;
	}

	/**
	 * 获取替换字符串
	 * @param replaceChar
	 * @param length
	 * @return
	 * @version 1.0
	 */
	private 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
	 * @version 1.0
	 */
	@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;
	}

}
</span>
附件:敏感词汇表(SensitiveWord.txt)