stringtokenizer.java

轻量嵌入JVM,可用于掌上设备手机等手持消息设备．

/************************************************************************
This file is part of java core libraries for the simpleRTJ virtual machine.

This file is covered by the GNU GPL with the following exception:
  As a special exception, the copyright holders of this library give you permission
  to link this library with independent modules to produce an executable, regardless
  of the license terms of these independent modules, and to copy and distribute the
  resulting executable under terms of your choice, provided that you also meet, for
  each linked independent module, the terms and conditions of the license of that
  module. An independent module is a module which is not derived from or based on
  this library. If you modify this library, you may extend this exception to your
  version of the library, but you are not obligated to do so. If you do not wish
  to do so, delete this exception statement from your version.


THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY,  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL RTJ COMPUTING BE LIABLE FOR ANY CLAIM, DAMAGES
OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Created/modified by:
    RTJ Computing
***********************************************************************/
package java.util;

import java.lang.*;

public class StringTokenizer implements Enumeration
{
    private String input;
    private String delims;
    private boolean retDelim;
    private int position;

    public StringTokenizer(String str)
    {
        this (str, " \t\n\r\f");
    }

    public StringTokenizer(String str, String delim)
    {
        this (str, delim, false);
    }

    public StringTokenizer(String input, String delims, boolean retDelim)
    {
        this.input = input;
        this.delims = delims;
        this.retDelim = retDelim;
        position = 0;
    }

    public int countTokens()
    {
        int count = 0;

        int curPos = position;
        while (nextTokenInternal(false) != null)
            count++;
        position = curPos;

        return count;
    }

    public boolean hasMoreElements()
    {
        return hasMoreTokens();
    }


    public boolean hasMoreTokens()
    {
        int oldPosition = position;
        String ret = nextTokenInternal(false);
        position = oldPosition;
        if (ret == null)
            return false;
        return true;
    }

    public Object nextElement()
    {
        return (Object)nextToken();
    }

    public String nextToken(String delims)
    {
        this.delims = delims;
        return nextToken();
    }

    public String nextToken()
    {
        String ret = nextTokenInternal(true);
        if (ret == null)
            throw new NoSuchElementException("no more elements");
        return ret;
    }

    private String nextTokenInternal(boolean retStr)
    {
        if (position >= input.length())
            return null;

        if (delims.indexOf(input.charAt(position)) != -1)
        {
            position++;
            if (retDelim)
            {
                if (retStr)
                    return input.substring(position-1, position);
                return input;
            }
            while (true)
            {
                if (position >= input.length())
                    return null;
                if (delims.indexOf(input.charAt(position)) == -1)
                    break;
                position++;
            }
        }

        int start = position;
        while (true)
        {
            position++;
            if (position >= input.length() || delims.indexOf(input.charAt(position)) != -1)
                break;
        }

        if (retStr)
            return input.substring(start, position);
        return input;
    }
}