java DFA 敏感词过滤

DFA算法介绍见这篇博文:
http://blog.csdn.net/chenssy/article/details/26961957
直接贴代码:

@SuppressWarnings("unchecked")
public class SensitiveWordUtils
{
/**
 * 只要匹配到一个就返回
 */
public static final int MATCHTYPE_MIN = 1 << 0;

/**
 * 统计所有敏感词
 */
public static final int MATCHTYPE_ALL = 1 << 1;

/**
 * map 中的结束标志
 */
private static final String END = "1";

private static final String END_NOT = "0";

private static final Map<String, Object> sensitiveWordMap = new HashMap<>();

@SuppressWarnings("serial")
private static final Set<String> sensitiveWordSets = new HashSet<String>()
    {
        {
            add("日本人");
            add("本来啊");
        }
    };

static
    {
        Map<String, Object> newWordMap = null;
        Map<String, Object> addMap = null;
for (String keywords : sensitiveWordSets)
        {
            newWordMap = sensitiveWordMap;
for (int i = 0; i < keywords.length(); i++)
            {
                String c = String.valueOf(keywords.charAt(i));
                Object o = newWordMap.get(c);
if (null == o)
                {
                    addMap = new HashMap<String, Object>();
                    addMap.put("isEnd", END_NOT); // 不是最后一个
                    newWordMap.put(c, addMap);
                    newWordMap = addMap;
                }
else
                {
                    newWordMap = (Map<String, Object>)o;
                }

if (i == keywords.length() - 1)
                {
                    newWordMap.put("isEnd", END); // 最后一个
                }
            }
        }
    }

/**
 * 敏感词匹配,返回匹配到的敏感词数量
 * 
 * @Description
 * @param str 需要匹配的字符
 * @param beginIndex 开始匹配位置
 * @param matchType 匹配规则: MATCHTYPE_MIN(只要匹配到一个敏感词就返回) MATCHTYPE_ALL(返回匹配到的所有敏感词数量)
 * @return
 */
public static int checkSensitiveWord(String str, int beginIndex, int matchType)
    {
int mark = 0;
        Map<String, Object> newWordMap = null;
        Object o;
for (int i = beginIndex; i < str.length(); i++)
        {
            newWordMap = sensitiveWordMap;
int j = i;
while (j < str.length())
            {
                o = newWordMap.get(String.valueOf(str.charAt(j)));
if (o == null)
                {
break;
                }
else
                {
                    newWordMap = (Map<String, Object>)o;
if (END.equals(newWordMap.get("isEnd").toString()))
                    {
                        mark++;
if (matchType == MATCHTYPE_MIN)
                        {
return mark;
                        }
break;
                    }
                }
                j++;
            }
        }
return mark;
    }

/**
 * 返回匹配到的敏感词
 * 
 * @Description
 * @param str
 * @param beginIndex 开始匹配位置
 * @param matchType 匹配规则
 * @return
 */
public static Set<String> firstSensitiveWord(String str, int beginIndex, int matchType)
    {
        Set<String> set = new HashSet<>();
        Map<String, Object> newWordMap = null;
        Object o;
for (int i = beginIndex; i < str.length(); i++)
        {
            newWordMap = sensitiveWordMap;
int j = i;
while (j < str.length())
            {
                o = newWordMap.get(String.valueOf(str.charAt(j)));
if (o == null)
                {
break;
                }
else
                {
                    newWordMap = (Map<String, Object>)o;
if (END.equals(newWordMap.get("isEnd").toString()))
                    {
                        set.add(str.substring(i, j + 1));
if (matchType == MATCHTYPE_MIN)
                        {
return set;
                        }
break;
                    }
                }
                j++;
            }
        }
return set;
    }

public static void main(String[] args)
    {
        System.out.println(checkSensitiveWord("日本来啊日本人", 0, MATCHTYPE_ALL));
    }
}

代码中 sensitiveWordMap 为{日={本={男={人={isEnd=1}, isEnd=0}, 人={isEnd=1}, isEnd=0}, isEnd=0}, 法={isEnd=0, 轮={isEnd=0, 功={isEnd=1}}}}