Merge pull request #496 from scireum/feature/mko/SIRI-885

Adds a new helper for dates (called Dates) which provides convenience methods

src/main/java/sirius/kernel/commons/Dates.java

@@ -0,0 +1,118 @@
+/*
+ * Made with all the love in the world
+ * by scireum in Remshalden, Germany
+ *
+ * Copyright by scireum GmbH
+ * http://www.scireum.de - info@scireum.de
+ */
+
+package sirius.kernel.commons;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Provides various helper methods for dealing with dates.
+ */
+public class Dates {
+
+    /**
+     * All methods are static, therefore no instances are required.
+     */
+    private Dates() {
+    }
+
+    /**
+     * Computes the latest date-time of the given date-time objects.
+     *
+     * @param dateTimes the date-time objects to compare
+     * @return the latest date-time object or <tt>null</tt> if no date is given
+     */
+    public static LocalDateTime computeLatestDateTime(LocalDateTime... dateTimes) {
+        return Dates.computeLatestDateTime(Arrays.asList(dateTimes));
+    }
+
+    /**
+     * Computes the latest date-time of the given date-time objects.
+     *
+     * @param dateTimes a list of date-time objects to compare
+     * @return the latest date-time object or <tt>null</tt> if no date is given
+     */
+    public static LocalDateTime computeLatestDateTime(List<LocalDateTime> dateTimes) {
+        return dateTimes.stream()
+                        .filter(Objects::nonNull)
+                        .max(LocalDateTime::compareTo)
+                        .orElse(null);
+    }
+
+    /**
+     * Computes the latest date of the given date objects.
+     *
+     * @param dates the dates to compare
+     * @return the latest date object or <tt>null</tt> if no date is given
+     */
+    public static LocalDate computeLatestDate(LocalDate... dates) {
+        return computeLatestDate(Arrays.asList(dates));
+    }
+
+    /**
+     * Computes the latest date of the given date objects.
+     * @param dates a list of date objects to compare
+     * @return the latest date object or <tt>null</tt> if no date is given
+     */
+    public static LocalDate computeLatestDate(List<LocalDate> dates) {
+        return dates.stream()
+                    .filter(Objects::nonNull)
+                    .max(LocalDate::compareTo)
+                    .orElse(null);
+    }
+
+    /**
+     * Computes the earliest date-time of the given date-time objects.
+     *
+     * @param dateTimes the date-time objects to compare
+     * @return the earliest date-time object or <tt>null</tt> if no date is given
+     */
+    public static LocalDateTime computeEarliestDateTime(LocalDateTime... dateTimes) {
+        return computeEarliestDateTime(Arrays.asList(dateTimes));
+    }
+
+    /**
+     * Computes the earliest date-time of the given date-time objects.
+     *
+     * @param dateTimes a list of date-time objects to compare
+     * @return the earliest date-time object or <tt>null</tt> if no date is given
+     */
+    public static LocalDateTime computeEarliestDateTime(List<LocalDateTime> dateTimes) {
+        return dateTimes.stream()
+                        .filter(Objects::nonNull)
+                        .min(LocalDateTime::compareTo)
+                        .orElse(null);
+    }
+
+    /**
+     * Computes the earliest date of the given date objects.
+     *
+     * @param dates the dates to compare
+     * @return the earliest date object or <tt>null</tt> if no date is given
+     */
+    public static LocalDate computeEarliestDate(LocalDate... dates) {
+        return computeEarliestDate(Arrays.asList(dates));
+    }
+
+    /**
+     * Computes the earliest date of the given date objects.
+     *
+     * @param dates a list of date objects to compare
+     * @return the earliest date object or <tt>null</tt> if no date is given
+     */
+    public static LocalDate computeEarliestDate(List<LocalDate> dates) {
+        return dates.stream()
+                    .filter(Objects::nonNull)
+                    .min(LocalDate::compareTo)
+                    .orElse(null);
+    }
+}

src/test/kotlin/sirius/kernel/commons/DatesTest.kt

@@ -0,0 +1,54 @@
+/*
+ * Made with all the love in the world
+ * by scireum in Remshalden, Germany
+ *
+ * Copyright by scireum GmbH
+ * http://www.scireum.de - info@scireum.de
+ */
+
+package sirius.kernel.commons
+
+import java.time.LocalDate
+import java.time.LocalDateTime
+import kotlin.test.*
+
+/**
+ * Tests the [Dates] class.
+ */
+class DatesTest {
+    @Test
+    fun computeLatestDateTime() {
+        val theDayBeforeYesterday = LocalDateTime.now().minusDays(2)
+        val yesterday = LocalDateTime.now().minusDays(1)
+        val now = LocalDateTime.now()
+        assertEquals(now, Dates.computeLatestDateTime(null, theDayBeforeYesterday, now, yesterday))
+        assertEquals(null, Dates.computeLatestDateTime(null, null, null))
+    }
+
+    @Test
+    fun computeLatestDate() {
+        val theDayBeforeYesterday = LocalDate.now().minusDays(2)
+        val yesterday = LocalDate.now().minusDays(1)
+        val now = LocalDate.now()
+        assertEquals(now, Dates.computeLatestDate(null, theDayBeforeYesterday, now, yesterday))
+        assertEquals(null, Dates.computeLatestDate(null, null, null))
+    }
+
+    @Test
+    fun computeEarliestDateTime() {
+        val theDayBeforeYesterday = LocalDateTime.now().minusDays(2)
+        val yesterday = LocalDateTime.now().minusDays(1)
+        val now = LocalDateTime.now()
+        assertEquals(theDayBeforeYesterday, Dates.computeEarliestDateTime(null, theDayBeforeYesterday, now, yesterday))
+        assertEquals(null, Dates.computeEarliestDateTime(null, null, null))
+    }
+
+    @Test
+    fun computeEarliestDate() {
+        val theDayBeforeYesterday = LocalDate.now().minusDays(2)
+        val yesterday = LocalDate.now().minusDays(1)
+        val now = LocalDate.now()
+        assertEquals(theDayBeforeYesterday, Dates.computeEarliestDate(null, theDayBeforeYesterday, now, yesterday))
+        assertEquals(null, Dates.computeEarliestDate(null, null, null))
+    }
+}