Filter sensitive word DFA Java implementation

Tag: ber false tostring TNO trim private list slf4j byte

 PackageCom.member.schedule;Importjava.io.UnsupportedEncodingException;ImportJava.nio.ByteBuffer;ImportJava.nio.charset.Charset;Importjava.util.List;ImportOrg.slf4j.Logger;Importorg.slf4j.LoggerFactory;/** * @authorXu Liangyong * @Date 2011-10-13 a.m. 9:23:43*/ Public classDFA {Private Static FinalLogger Logger = Loggerfactory.getlogger (DFA.class); /*** Root node*/    PrivateTreeNode RootNode =NewTreeNode (); /*** Keyword Cache*/    PrivateBytebuffer Keywordbuffer = bytebuffer.allocate (1024); /*** Keyword Code*/    PrivateString charset = "GBK"; /*** Create DFA * *@paramKeywordList *@throwsunsupportedencodingexception*/     Public voidCreatekeywordtree (list<string> keywordlist)throwsunsupportedencodingexception { for(String keyword:keywordlist) {if(keyword = =NULL)                Continue; Keyword=Keyword.trim (); byte[] bytes =keyword.getbytes (CharSet); TreeNode Tempnode=RootNode; //loop per byte             for(inti = 0; i < bytes.length; i++) {                intindex = bytes[i] & 0xff;//convert characters into numbersTreeNode node =Tempnode.getsubnode (index); if(node = =NULL) {//not initializednode =NewTreeNode ();                Tempnode.setsubnode (Index, node); } Tempnode=node; if(i = = Bytes.length-1) {tempnode.setkeywordend (true);//end of keyword, set end flagLogger.debug ("dfa:{}", keyword); }            } //End for}//End for    }    /*** Search Keywords*/     PublicString SearchKeyword (String text)throwsunsupportedencodingexception {returnSearchKeyword (Text.getbytes (charset)); }    /*** Search Keywords*/     PublicString SearchKeyword (byte[] bytes) {StringBuilder words=NewStringBuilder (); if(bytes = =NULL|| Bytes.length = = 0) {            returnwords.tostring (); } TreeNode Tempnode=RootNode; intRollback = 0;//Roll Back number        intPosition = 0;//location of the current comparison         while(Position <bytes.length) {intindex = bytes[position] & 0xFF; Keywordbuffer.put (Bytes[position]); //Write keyword CacheTempnode =Tempnode.getsubnode (index); //match end of current position            if(Tempnode = =NULL) {Position= Position-rollback;//fallback and test the next byteRollback = 0; Tempnode= RootNode;//state Machine ResetKeywordbuffer.clear ();//Clear}Else if(Tempnode.iskeywordend ()) {//is the end point record keywordKeywordbuffer.flip (); String keyword=charset.forname (Charset). Decode (Keywordbuffer). toString (); Logger.debug ("Find keyword:{}", keyword);                Keywordbuffer.limit (Keywordbuffer.capacity ()); if(words.length () = = 0) words.append (keyword); ElseWords.append (":"). append (keyword); Rollback= 1;//encounter end point rollback to 1}Else{rollback++;//non-end-point fallback number plus 1} position++; }        returnwords.tostring (); }     Public voidSetcharset (String charset) { This. CharSet =CharSet; }}

 PackageCom.member.schedule;Importjava.util.ArrayList;Importjava.util.List;/*** Tree nodes Each node contains an array of length 256 * *@authorXu Liangyong * @Date 2011-10-12 a.m. 3:11:24*/ Public classTreeNode {Private Static Final intNode_len = 256; /*** true keywords end; false continue*/    Private BooleanEnd =false; Privatelist<treenode> subnodes =NewArraylist<treenode>(Node_len);  PublicTreeNode () { for(inti = 0; i < Node_len; i++) {Subnodes.add (I,NULL); }    }    /*** Add a node tree to a specified location * *@paramIndex *@paramnode*/     Public voidSetsubnode (intindex, TreeNode node)    {Subnodes.set (Index, node); }     PublicTreeNode Getsubnode (intindex) {        returnSubnodes.get (index); }     Public BooleanIskeywordend () {returnend; }     Public voidSetkeywordend (Booleanend) {         This. end =end; }}

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Filter sensitive word DFA Java implementation