bigstring.java

简易模拟电梯系统

        	return this.substr(start,StringLength);
        }
        
        /**
         *  Return the string representation of the char argument.
         */
        public BigString valueOf(char c)
        {
        	BigString bs=new BigString(""+c);
        	return bs;
        }
        	    
	    /**
	     *  Returns the string representation of the int argument.
	     */
        public BigString valueOf(int i)
        {
            BigString bs=new BigString(""+i);
            return bs;
        }

	    /**
	     *  Returns the string representation of the long argument.
	     */
        public BigString valueOf(long l)
        {
            BigString bs=new BigString(""+l);
            return bs;
        }

	    /**
	     *  Returns the string representation of the float argument.
	     */
        public BigString valueOf(float f)
        {
            BigString bs=new BigString(""+f);
            return bs;
        }

	    /**
	     *  Returns the string representation of the bool argument.
	     */
        public BigString valueOf(boolean bool)
        {
            BigString bs=new BigString(""+bool);
            return bs;
        }

	    /**
	     *  Returns the string representation of a specific subarray 
	     *  of the char array argument.
	     */
        public BigString valueOf(char[]value)
        {
            BigString bs=new BigString(value);
            return bs;
        }

	    /**
	     *  Returns the string representation of the double argument. 
	     */
        public BigString valueOf(double d)
        {
            BigString bs=new BigString(""+d);
            return bs;
        }

	    /**
	     *  Returns the string representation of the Object argument. 
	     */
        public BigString valueOf(Object obj)
        {
            BigString bs=new BigString(obj.toString());
            return bs;
        }
        
	    /**
	     *  The method be used as the method at String.java.
	     *  And the use can be hypothesize from the name.
	     *  @return char
	     *  <br>The charactor which you want to get at the 
	     *  Index of number index.
	     *  @param index A long type value.
	     */
        public char charAt(long index)
        {
        	//String str=this.toString();
            return bt.charAt(index);
            //charAt((int)index);
        }
        
        /**
         *  The get methods.
         */
        /**
         *  Get the StringLength of the BigString, may equalsto treeLimit+1; 
         *  @return long 
         *  <br>the length of BigString.
         */ 
        public long Length()
        {
            return this.StringLength;
        }


        /** 
         *  A public get method.
         *  Get the start of the BigSting
         *  @return long
         *  the start index
         */
         protected long getStart()
         {
         	return start;
         }


		
        /** 
         *  Get the container of the BigString, which contains nodes of the B+Tree.
         *  @return Vector
         *  @see java.util.Vector
         *  return the vec of the BigString.
         */
        protected Vector getVect()
        {
            return vec;
        }
        
		/** 
		 *  Get the data structure of the BigString
		 *  @return BTreeString 
		 *  <br>return the bt of the BigString
		 */		
        protected BTreeString getMyBTree()
        {
            return bt;
        }
		
		/**
		 *  Get the size of the char array which the actual BigString contains.
		 *  @return long 
		 *  <br>the treeLimit of the actual BigString
		 */
        protected long getTreeLim()
        {
            return treeLimit;
        }
        
        /**
         *  Private method, return a string type substring.
         */
        private String substr(long begin, long end) throws
			StringIndexOutOfBoundsException //Exception to be thrown
	    {
	    	//System.out.println(end-begin);
	    	//solve exceptions
	    	//when the start is great than begin
	    	//or the from is smaller than end
	    	//or the end is greater than StringLength.
			if(!(start <= begin && begin <= end && end <= start + StringLength))