[LANG-1505] Add StopWatch convenience APIs to format times and create a

simple instance.

src/changes/changes.xml

@@ -87,6 +87,7 @@ The <action> type attribute can be add,update,fix,remove.
     <action                   type="update" dev="ggregory" due-to="Peter Verhas">BooleanUtils Javadoc #469.</action>
     <action                   type="update" dev="ggregory" due-to="Peter Verhas">Functions Javadoc #466.</action>
     <action issue="LANG-1503" type="add" dev="ggregory" due-to="XenoAmess, Gary Gregory">Add factory methods to Pair classes with Map.Entry input. #454.</action>
+    <action issue="LANG-1505" type="add" dev="ggregory" due-to="Gary Gregory">Add StopWatch convenience APIs to format times and create a simple instance.</action>
   </release>
 
   <release version="3.9" date="2019-04-09" description="New features and bug fixes. Requires Java 8, supports Java 9, 10, 11.">

src/main/java/org/apache/commons/lang3/time/StopWatch.java

@@ -160,6 +160,17 @@ boolean isSuspended() {
 
     private static final long NANO_2_MILLIS = 1000000L;
 
+    /**
+     * Creates a stopwatch for convenience.
+     *
+     * @return StopWatch a stopwatch.
+     *
+     * @since 3.10
+     */
+    public static StopWatch create() {
+        return new StopWatch();
+    }
+
     /**
      * Creates a started stopwatch for convenience.
      *
@@ -209,6 +220,26 @@ public StopWatch() {
         super();
     }
 
+    /**
+     * Returns the time formatted by {@link DurationFormatUtils#formatDurationHMS}.
+     *
+     * @return the time formatted by {@link DurationFormatUtils#formatDurationHMS}.
+     * @since 3.10
+     */
+    public String formatSplitTime() {
+        return DurationFormatUtils.formatDurationHMS(getSplitTime());
+    }
+
+    /**
+     * Returns the split time formatted by {@link DurationFormatUtils#formatDurationHMS}.
+     *
+     * @return the split time formatted by {@link DurationFormatUtils#formatDurationHMS}.
+     * @since 3.10
+     */
+    public String formatTime() {
+        return DurationFormatUtils.formatDurationHMS(getTime());
+    }
+
     /**
      * <p>
      * Gets the time on the stopwatch in nanoseconds.

src/test/java/org/apache/commons/lang3/time/StopWatchTest.java

@@ -17,6 +17,7 @@
 package org.apache.commons.lang3.time;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -144,6 +145,20 @@ public void testBooleanStates() {
         assertTrue(watch.isStopped());
     }
 
+    @Test
+    public void testFormatSplitTime() throws InterruptedException {
+        final StopWatch watch = StopWatch.createStarted();
+        Thread.sleep(20);
+        watch.split();
+        assertNotEquals("00:00:00.000", watch.formatSplitTime());
+    }
+
+    @Test
+    public void testFormatTime() {
+        final StopWatch watch = StopWatch.create();
+        assertEquals("00:00:00.000", watch.formatTime());
+    }
+
     @Test
     public void testGetStartTime() {
         final long beforeStopWatch = System.currentTimeMillis();