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copied!<p>You can take timestamp snapshots before and after, then <strong>repeat the experiments several times to average to results</strong>. There are also profilers that can do this for you.</p> <hr> <h2>From "Java Platform Performance: Strategies and Tactics" book:</h2> <p><strong>With System.currentTimeMillis()</strong></p> <pre><code>class TimeTest1 { public static void main(String[] args) { long startTime = System.currentTimeMillis(); long total = 0; for (int i = 0; i < 10000000; i++) { total += i; } long stopTime = System.currentTimeMillis(); long elapsedTime = stopTime - startTime; System.out.println(elapsedTime); } } </code></pre> <p><strong>With a StopWatch class</strong></p> <p>You can use this <code>StopWatch</code> class, and call <code>start()</code> and <code>stop</code> before and after the method.</p> <pre><code>class TimeTest2 { public static void main(String[] args) { Stopwatch timer = new Stopwatch().start(); long total = 0; for (int i = 0; i < 10000000; i++) { total += i; } timer.stop(); System.out.println(timer.getElapsedTime()); } } </code></pre> <p>See <a href="http://java.sun.com/docs/books/performance/1st_edition/html/JPMeasurement.fm.html" rel="noreferrer">here</a>.</p> <hr> <h2>NetBeans Profiler:</h2> <blockquote> <p><strong>Application Performance Application</strong></p> <p>Performance profiles <strong>method-level CPU performance (execution time)</strong>. You can choose to profile the entire application or a part of the application.</p> </blockquote> <p>See <a href="http://profiler.netbeans.org/docs/help/5.5/profile_analyze_short.html" rel="noreferrer">here</a>.</p>

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