public WordInfo getNextN(String[] data, int index, int N) {
		StringBuilder sb = new StringBuilder();
		int i = index;
		while(sb.length()<N&&i<data.length){			
			sb.append(data[i]);
			i++;
		}
		if(sb.length()<=N)	
			return new WordInfo(sb.toString(),i-index);
		else
			return new WordInfo(sb.substring(0,N),i-index);
	}
public WordInfo getNextN ( String [ ] data , int index , int N ) { StringBuilder sb = new StringBuilder ( ) ; int i = index ; while ( sb . length ( ) < N && i < data . length ) { sb . append ( data [ i ] ) ; i ++ ; } if ( sb . length ( ) <= N ) return new WordInfo ( sb . toString ( ) , i - index ) ; else return new WordInfo ( sb . substring ( 0 , N ) , i - index ) ; }
得到从位置index开始的长度为N的字串
@param data String[]
@param index 起始位置
@param N 长度
@return