package com.ronsoft.books.nio.regex;
import java.util.regex.Pattern;
import java.util.List;
import java.util.LinkedList;
/**
* Demonstrate behavior of splitting strings. The XML output created
* here can be styled into HTML or some other useful form.
* See poodle.xsl.
*
* Created: April, 2002
* @author Ron Hitchens (ron@ronsoft.com)
* @version $Id: Poodle.java,v 1.3 2002/05/01 03:47:07 ron Exp $
*/
public class Poodle
{
/**
* Generate a matrix table of how Pattern.split() behaves with
* various regex patterns and limit values.
*/
public static void main (String [] argv)
throws Exception
{
String input = "poodle zoo";
Pattern space = Pattern.compile (" ");
Pattern d = Pattern.compile ("d");
Pattern o = Pattern.compile ("o");
Pattern [] patterns = { space, d, o };
int limits [] = { 1, 2, 5, -2, 0 };
// Use supplied args, if any. Assume args are good.
// Usage: input pattern [pattern ...]
// Don't forget to quote the args.
if (argv.length != 0) {
input = argv [0];
patterns = collectPatterns (argv);
}
generateTable (input, patterns, limits);
}
/**
* Output a simple XML document with the results of applying
* the list of regex patterns to the input with each of the
* limit values provided. I should probably use the JAX APIs
* to do this, but I want to keep the code simple.
*/
private static void generateTable (String input,
Pattern [] patterns, int [] limits)
{
System.out.println ("<?xml version='1.0'?>");
System.out.println ("<table>");
System.out.println ("\t<row>");
System.out.println ("\t\t<head>Input: "
+ input + "</head>");
for (int i = 0; i < patterns.length; i++) {
Pattern pattern = patterns [i];
System.out.println ("\t\t<head>Regex: <value>"
+ pattern.pattern() + "</value></head>");
}
System.out.println ("\t</row>");
for (int i = 0; i < limits.length; i++) {
int limit = limits [i];
System.out.println ("\t<row>");
System.out.println ("\t\t<entry>Limit: "
+ limit + "</entry>");
for (int j = 0; j < patterns.length; j++) {
Pattern pattern = patterns [j];
String [] tokens = pattern.split (input, limit);
System.out.print ("\t\t<entry>");
for (int k = 0; k < tokens.length; k++) {
System.out.print ("<value>"
+ tokens [k] + "</value>");
}
System.out.println ("</entry>");
}
System.out.println ("\t</row>");
}
System.out.println ("</table>");
}
/**
* If command line args were given, compile all args after the
* first as a Pattern. Return an array of Pattern objects.
*/
private static Pattern [] collectPatterns (String [] argv)
{
List list = new LinkedList();
for (int i = 1; i < argv.length; i++) {
list.add (Pattern.compile (argv [i]));
}
Pattern [] patterns = new Pattern [list.size()];
list.toArray (patterns);
return (patterns);
}
}