StringUtil.java Source code

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Here is the source code for StringUtil.java

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import java.util.StringTokenizer;

/* 
 * The Apache Software License, Version 1.1
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 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    distribution.
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 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
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 * 5. Products derived from this software may not be called "Apache"
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 * This software consists of voluntary contributions made by many
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 */

/**
 * max: Removed methods that dependent on anything else than common.StringUtils.
 * 
 * <p>Common <code>String</code> manipulation routines.</p>
 *
 * <p>Originally from 
 * <a href="http://jakarta.apache.org/turbine/">Turbine</a> and the
 * GenerationJavaCore library.</p>
 *
 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
 * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
 * @author <a href="mailto:gcoladonato@yahoo.com">Greg Coladonato</a>
 * @author <a href="mailto:bayard@generationjava.com">Henri Yandell</a>
 * @author <a href="mailto:ed@apache.org">Ed Korthof</a>
 * @author <a href="mailto:rand_mcneely@yahoo.com>Rand McNeely</a>
 * @author <a href="mailto:scolebourne@joda.org>Stephen Colebourne</a>
 * @author <a href="mailto:fredrik@westermarck.com>Fredrik Westermarck</a>
 * @version $Id$
 */
public class StringUtil {

    /**
     * Splits the provided text into a list, based on a given separator.
     * The separator is not included in the returned String array.
     * The maximum number of splits to perfom can be controlled.
     * A null separator will cause parsing to be on whitespace.
     *
     * <p>This is useful for quickly splitting a string directly into
     * an array of tokens, instead of an enumeration of tokens (as
     * <code>StringTokenizer</code> does).
     *
     * @param str The string to parse.
     * @param separator Characters used as the delimiters. If
     * <code>null</code>, splits on whitespace.
     * @param max The maximum number of elements to include in the
     * list.  A zero or negative value implies no limit.
     * @return an array of parsed Strings 
     */
    public static String[] split(String str, String separator, int max) {
        StringTokenizer tok = null;
        if (separator == null) {
            // Null separator means we're using StringTokenizer's default
            // delimiter, which comprises all whitespace characters.
            tok = new StringTokenizer(str);
        } else {
            tok = new StringTokenizer(str, separator);
        }

        int listSize = tok.countTokens();
        if (max > 0 && listSize > max) {
            listSize = max;
        }

        String[] list = new String[listSize];
        int i = 0;
        int lastTokenBegin = 0;
        int lastTokenEnd = 0;
        while (tok.hasMoreTokens()) {
            if (max > 0 && i == listSize - 1) {
                // In the situation where we hit the max yet have
                // tokens left over in our input, the last list
                // element gets all remaining text.
                String endToken = tok.nextToken();
                lastTokenBegin = str.indexOf(endToken, lastTokenEnd);
                list[i] = str.substring(lastTokenBegin);
                break;
            } else {
                list[i] = tok.nextToken();
                lastTokenBegin = str.indexOf(list[i], lastTokenEnd);
                lastTokenEnd = lastTokenBegin + list[i].length();
            }
            i++;
        }
        return list;
    }

}