java.lang.ArithmeticException: long overflow

java.lang.Math.addExact(Math.java:932) at
org.apache.commons.io.file.attribute.FileTimes.ntfsTimeToDate(long)

Author: garydgregory

src/changes/changes.xml

@@ -68,6 +68,7 @@ The <action> type attribute can be add,update,fix,remove.
       <action dev="ggregory" type="fix" issue="IO-870" due-to="Gary Gregory">PathUtils.copyFileToDirectory() across file systems #728.</action>
       <action dev="ggregory" type="fix" issue="IO-871" due-to="Éamonn McManus, Gary Gregory">IOUtils.contentEquals is incorrect when InputStream.available under-reports.</action>
       <action dev="ggregory" type="fix" issue="IO-873" due-to="Gary Gregory">java.lang.ArithmeticException: long overflow java.lang.Math.addExact(Math.java:932) at org.apache.commons.io.file.attribute.FileTimes.ntfsTimeToFileTime(FileTimes.java:164). See also https://issues.apache.org/jira/browse/MDEP-978.</action>
+      <action dev="ggregory" type="fix" issue="IO-873" due-to="Gary Gregory">java.lang.ArithmeticException: long overflow java.lang.Math.addExact(Math.java:932) at org.apache.commons.io.file.attribute.FileTimes.ntfsTimeToDate(long).</action>
       <!-- ADD -->
       <action dev="ggregory" type="add" issue="IO-860" due-to="Nico Strecker, Gary Gregory">Add ThrottledInputStream.Builder.setMaxBytes(long, ChronoUnit).</action>
       <action dev="ggregory" type="add"                due-to="Gary Gregory">Add IOIterable.</action>

src/main/java/org/apache/commons/io/file/attribute/FileTimes.java

@@ -151,6 +151,10 @@ public static FileTime now() {
         return FileTime.from(Instant.now());
     }
 
+    static Date ntfsTimeToDate(final BigDecimal ntfsTime) {
+        return new Date(ntfsTimeToInstant(ntfsTime).toEpochMilli());
+    }
+
     /**
      * Converts NTFS time (100 nanosecond units since 1 January 1601) to Java time.
      * <p>
@@ -162,9 +166,7 @@ public static FileTime now() {
      * @see <a href="https://learn.microsoft.com/en-us/windows/win32/sysinfo/file-times">NTFS File Times</a>
      */
     public static Date ntfsTimeToDate(final long ntfsTime) {
-        final long javaHundredNanos = Math.addExact(ntfsTime, UNIX_TO_NTFS_OFFSET);
-        final long javaMillis = Math.floorDiv(javaHundredNanos, HUNDRED_NANOS_PER_MILLISECOND);
-        return new Date(javaMillis);
+        return ntfsTimeToDate(BigDecimal.valueOf(ntfsTime));
     }
 
     /**

src/test/java/org/apache/commons/io/file/attribute/FileTimesTest.java

@@ -194,9 +194,9 @@ public void testMinusSeconds() {
     }
 
     @ParameterizedTest
-    @MethodSource("dateToNtfsProvider")
+    @MethodSource("fileTimeNanoUnitsToNtfsProvider")
     public void testNtfsTimeToDate(final String instant, final long ntfsTime) {
-        assertEquals(Instant.parse(instant), FileTimes.ntfsTimeToDate(ntfsTime).toInstant());
+        assertEquals(Instant.parse(instant).toEpochMilli(), FileTimes.ntfsTimeToDate(ntfsTime).toInstant().toEpochMilli());
     }
 
     @ParameterizedTest