/** LineFieldsParser.java - reads in each line from a file and splits it into fields
    By Rowland http://home.comcast.net/~rowland3/  **/

import java.io.*;
import java.util.*;

//------------------------------------------------------------------------------
public class LineFieldsParser  {
    protected LineNumberReader in;
    protected int token;
    protected boolean gotToken;
    protected StringTokenizer st;

    public LineFieldsParser(String fileSpec) throws Exception  {
	File file= new File(fileSpec);
	if (!file.exists())  throw new IOException("No such file: "+ fileSpec);
	Reader reader= new InputStreamReader(new FileInputStream(fileSpec));
	in= new LineNumberReader(reader);
	run();
    } 
    public LineFieldsParser(InputStreamReader reader) throws Exception  {
	in= new LineNumberReader(reader);
	run();
    }

    protected void run() {
	String line;
	try {
	    while ((line=in.readLine())!= null)
		doLine(line);
	    in.close();
	}
	catch (Exception E) { System.err.println("ERR LineFieldsParser run: "+ E.getMessage()); }
    }

    protected void doLine(String line) {
	StringTokenizer st= new StringTokenizer(line);
	Vector v= new Vector();
	while (st.hasMoreTokens()) {
	    String field= st.nextToken();
	    v.add(field);
	}
	st= null;
	Object[] fields= v.toArray();
	v= null;
	try { callback(fields); }
	catch (Exception E) { System.err.println("ERR LineFieldsParser callback: "+ E.getMessage()); }
    }

    /** callback - override in derived class.  Gets fed an array of fields for each line **/
    protected void callback(Object[] fields)  throws Exception  {
	for (int i= 0; i<fields.length; i++)
	    System.out.print("["+ (String)fields[i]+ "]  ");
	System.out.println("");
    }

    /** main() test harness.  Pass file spec on command line **/
    public static void main(String args[]) {
	try { new LineFieldsParser(args[0]);} 
	catch (Exception E) { System.err.println("ERR LineFieldsParser main: "+ E.getMessage()); }
    }
}