advstringtokenizer.java~24~

一个简单的数据库管理系统

package com.nay0648.util;
import java.util.*;

/**advanced stringtokenizer
 * <p>Title: </p>
 * <p>Description: </p>
 * it can analize any string token
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */
public class AdvStringTokenizer
{
private String origin,current;//origin string,current string
private Set delim;//delimiters

	/**construct a new tokenizer*/
	public AdvStringTokenizer()
	{
		delim=new HashSet();//selimiter set
	}

	/**add default delimiters to delimiter set,they are space character*/
	public void addDefaltDelim()
	{
		delim.add(new Character(' '));
		delim.add(new Character('\r'));
		delim.add(new Character('\n'));
		delim.add(new Character('\t'));
	}

	/**clear all delimiters*/
	public void clearDelim()
	{
		delim.clear();
	}

	/**add a delimiter*/
	public void addDelim(char c)
	{
		delim.add(new Character(c));
	}

	/**remove a delimiter*/
	public void removeDelim(char c)
	{
		delim.remove(new Character(c));
	}

	/**to see if the string has next token*/
	public boolean hasMoreTokens()
	{
		if(current.length()>0) return true;else return false;
	}

	/**set a new string*/
	public void setString(String s)
	{
		int i;

		origin=s;
		for(i=origin.length()-1;i>=0;i--)
			if(!delim.contains(new Character(origin.charAt(i)))) break;//cut tail
		current=origin.substring(0,i+1);
	}

	/**get the next token*/
	public String nextToken()
	{
		int head,tail;
		String token;

		for(head=0;head<current.length();head++)
			if(!delim.contains(new Character(current.charAt(head)))) break;
		for(tail=head;tail<current.length();tail++)
			if(delim.contains(new Character(current.charAt(tail))))break;
		token=current.substring(head,tail);
		current=current.substring(tail);
		return token;
	}
}