Java 过滤敏感字的算法

 

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 算法思路：把敏感词的第一个字符取出来，作为比较对象。
 * 遍历整个字符串，如果发现字符跟敏感词第一个字符相同，
 * 就从字符串取出跟关键词相同长度的子串比较，如果相同就替换
 *
 * 本算法比较适合敏感词都不长的场合
 * @author Administrator
 *
 */
public class WordFilter {
    private static Map<Character,List<String>> wordListToMap(List<String> sensitiveWordList){
        Map<Character,List<String>> result=new HashMap<Character,List<String>>();
        for (String s:sensitiveWordList){
            char c=s.charAt(0);
            List<String> strs=result.get(c);
            if (strs==null){
                strs=new ArrayList<String>();
                result.put(c,strs);
            }
            strs.add(s);
        }

        return result;
    }

    public static String filter(String src,List<String> sensitiveWordList){
        Map<Character,List<String>> wordMap=wordListToMap(sensitiveWordList);

        StringBuilder strb=new StringBuilder();
        for (int i=0;i<src.length();i++){
            char c=src.charAt(i);
            String find=null;
            if (wordMap.containsKey(c)){
                List<String> words=wordMap.get(c);
                for (String s:words){
                    String temp=src.substring(i,(s.length()<=(src.length()-i))?i+s.length():i);
                    if (s.equals(temp)){
                        find=s;
                        break;
                    }
                }
            }
            if (find!=null){
                strb.append("***");
                i+=(find.length()-1);
            } else {
                strb.append(c);
            }
        }
        return strb.toString();
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        List<String> wordList=new ArrayList<String>();
        wordList.add("TMD");
        wordList.add("变态");
        System.out.println(filter("你TMD，也太缺德了吧",wordList));
        System.out.println(filter("你TMD，也太缺德了TMD吧",wordList));
        System.out.println(filter("你TMD，也太缺德了吧TM",wordList));
        System.out.println(filter("你TMD，也太缺德了，太变态了吧TM",wordList));
        wordList.add("TM");
        System.out.println(filter("你TMD，也太缺德了，太变态了吧TM",wordList));
    }

}