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copied!<p>It's much easier to use a <a href="http://java.sun.com/javase/6/docs/api/java/util/regex/Matcher.html" rel="noreferrer"><code>java.util.regex.Matcher</code></a> and do a <code>find()</code> rather than any kind of <code>split</code> in these kinds of scenario.</p> <p>That is, instead of defining the pattern for the <em>delimiter</em> between the tokens, you define the pattern for <em>the tokens themselves</em>.</p> <p>Here's an example:</p> <pre><code> String text = "1 2 \"333 4\" 55 6 \"77\" 8 999"; // 1 2 "333 4" 55 6 "77" 8 999 String regex = "\"([^\"]*)\"|(\\S+)"; Matcher m = Pattern.compile(regex).matcher(text); while (m.find()) { if (m.group(1) != null) { System.out.println("Quoted [" + m.group(1) + "]"); } else { System.out.println("Plain [" + m.group(2) + "]"); } } </code></pre> <p>The above prints (<a href="http://ideone.com/OXsUp" rel="noreferrer">as seen on ideone.com</a>):</p> <pre><code>Plain [1] Plain [2] Quoted [333 4] Plain [55] Plain [6] Quoted [77] Plain [8] Plain [999] </code></pre> <p>The pattern is essentially:</p> <pre><code>"([^"]*)"|(\S+) \_____/ \___/ 1 2 </code></pre> <p>There are 2 alternates:</p> <ul> <li>The first alternate matches the opening double quote, a sequence of anything but double quote (captured in group 1), then the closing double quote</li> <li>The second alternate matches any sequence of non-whitespace characters, captured in group 2</li> <li>The order of the alternates matter in this pattern</li> </ul> <p>Note that this does not handle escaped double quotes within quoted segments. If you need to do this, then the pattern becomes more complicated, but the <code>Matcher</code> solution still works.</p> <h3>References</h3> <ul> <li><a href="http://www.regular-expressions.info/brackets.html" rel="noreferrer">regular-expressions.info/Brackets for Grouping and Capturing</a>, <a href="http://www.regular-expressions.info/alternation.html" rel="noreferrer">Alternation with Vertical Bar</a>, <a href="http://www.regular-expressions.info/charclass.html" rel="noreferrer">Character Class</a>, <a href="http://www.regular-expressions.info/repeat.html" rel="noreferrer">Repetition with Star and Plus</a></li> </ul> <h3>See also</h3> <ul> <li><a href="http://www.regular-expressions.info/examplesprogrammer.html" rel="noreferrer">regular-expressions.info/Examples - Programmer - Strings</a> - for pattern with escaped quotes</li> </ul> <hr> <h3>Appendix</h3> <p>Note that <a href="http://java.sun.com/javase/6/docs/api/java/util/StringTokenizer.html" rel="noreferrer"><code>StringTokenizer</code></a> is a <em>legacy class</em>. It's recommended to use <a href="http://java.sun.com/javase/6/docs/api/java/util/Scanner.html" rel="noreferrer"><code>java.util.Scanner</code></a> or <a href="http://download.oracle.com/javase/6/docs/api/java/lang/String.html#split%28java.lang.String%29" rel="noreferrer"><code>String.split</code></a>, or of course <a href="http://java.sun.com/javase/6/docs/api/java/util/regex/Matcher.html" rel="noreferrer"><code>java.util.regex.Matcher</code></a> for most flexibility.</p> <h3>Related questions</h3> <ul> <li><a href="https://stackoverflow.com/questions/2873254/difference-between-a-deprecated-and-legacy-api">Difference between a Deprecated and Legacy API?</a></li> <li><a href="https://stackoverflow.com/questions/691184/scanner-vs-stringtokenizer-vs-string-split">Scanner vs. StringTokenizer vs. String.Split</a></li> <li><a href="https://stackoverflow.com/questions/3059333/validating-input-using-java-util-scanner/">Validating input using java.util.Scanner</a> - has many examples</li> </ul>

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