BAEL-994 - TemporalAdjuster in Java (#2227)

* Evaluation article: Different Types of Bean Injection in Spring

* added tests & changed configuration to Java-based config

* removed xml config files

* rename unit tests

* BAEL-972 - Apache Commons Text

* remove code from evaluation article

* remove code from evaluation article

* BAEL-972 - Apache Commons Text - added another example

* BAEL-972 - Apache Commons Text - just indentation

* BAEL-994 - TemporalAdjuster in Java

core-java/src/main/java/com/baeldung/temporaladjuster/CustomTemporalAdjuster.java

@@ -0,0 +1,23 @@
+package com.baeldung.temporaladjuster;
+
+import java.time.DayOfWeek;
+import java.time.temporal.ChronoField;
+import java.time.temporal.ChronoUnit;
+import java.time.temporal.Temporal;
+import java.time.temporal.TemporalAdjuster;
+
+public class CustomTemporalAdjuster implements TemporalAdjuster {
+
+    @Override
+    public Temporal adjustInto(Temporal temporal) {
+        DayOfWeek dayOfWeek = DayOfWeek.of(temporal.get(ChronoField.DAY_OF_WEEK));
+        int daysToAdd;
+        if (dayOfWeek == DayOfWeek.FRIDAY)
+            daysToAdd = 3;
+        else if (dayOfWeek == DayOfWeek.SATURDAY)
+            daysToAdd = 2;
+        else
+            daysToAdd = 1;
+        return temporal.plus(daysToAdd, ChronoUnit.DAYS);
+    }
+}

core-java/src/main/java/com/baeldung/temporaladjuster/TemporalAdjusterUtil.java

@@ -0,0 +1,31 @@
+package com.baeldung.temporaladjuster;
+
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+
+public class TemporalAdjusterUtil {
+
+    public static Calendar nextDayOfWeek(int dayOfWeek) {
+        Calendar date = Calendar.getInstance();
+        int difference = dayOfWeek - date.get(Calendar.DAY_OF_WEEK);
+        if (!(difference > 0)) {
+            difference += 7;
+        }
+        date.add(Calendar.DAY_OF_MONTH, difference);
+        return date;
+    }
+
+    @SuppressWarnings("static-access")
+    public static String getNextWorkingDay() {
+        Calendar calendar = Calendar.getInstance();
+        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
+        format.setCalendar(calendar);
+        if (calendar.DAY_OF_WEEK == Calendar.FRIDAY)
+            calendar.add(Calendar.DATE, 3);
+        if (calendar.DAY_OF_WEEK == Calendar.SATURDAY)
+            calendar.add(Calendar.DATE, 2);
+        else
+            calendar.add(Calendar.DATE, 1);
+        return format.format(calendar.getTime());
+    }
+}

core-java/src/test/java/com/baeldung/temporaladjusters/CustomTemporalAdjusterTest.java

@@ -0,0 +1,63 @@
+package com.baeldung.temporaladjusters;
+
+import java.text.SimpleDateFormat;
+import java.time.DayOfWeek;
+import java.time.LocalDate;
+import java.time.Period;
+import java.time.temporal.TemporalAdjuster;
+import java.time.temporal.TemporalAdjusters;
+import java.util.Calendar;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.baeldung.temporaladjuster.CustomTemporalAdjuster;
+import com.baeldung.temporaladjuster.TemporalAdjusterUtil;
+
+public class CustomTemporalAdjusterTest {
+
+    @Test
+    public void whenAdjustAndImplementInterface_thenNextWorkingDay() {
+        LocalDate localDate = LocalDate.now();
+        CustomTemporalAdjuster temporalAdjuster = new CustomTemporalAdjuster();
+        LocalDate nextWorkingDay = localDate.with(temporalAdjuster);
+
+        Assert.assertEquals(TemporalAdjusterUtil.getNextWorkingDay(), nextWorkingDay.toString());
+    }
+    
+    @Test
+    public void whenAdjust_thenNextWorkingDay() {
+        LocalDate localDate = LocalDate.now();
+        TemporalAdjuster temporalAdjuster = NEXT_WORKING_DAY;
+        LocalDate date = localDate.with(temporalAdjuster);
+
+        Assert.assertEquals(TemporalAdjusterUtil.getNextWorkingDay(), date.toString());
+    }
+
+    @Test
+    public void whenAdjust_thenFourteenDaysFromToday() {
+        LocalDate localDate = LocalDate.now();
+        TemporalAdjuster temporalAdjuster = (t) -> t.plus(Period.ofDays(14));
+        LocalDate result = localDate.with(temporalAdjuster);
+
+        Calendar calendar = Calendar.getInstance();
+        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
+        format.setCalendar(calendar);
+        calendar.add(Calendar.DATE, 14);
+        String fourteenDaysFromToday = format.format(calendar.getTime());
+
+        Assert.assertEquals(fourteenDaysFromToday, result.toString());
+    }
+
+    static TemporalAdjuster NEXT_WORKING_DAY = TemporalAdjusters.ofDateAdjuster(today -> {
+        DayOfWeek dayOfWeek = today.getDayOfWeek();
+        int daysToAdd;
+        if (dayOfWeek == DayOfWeek.FRIDAY)
+            daysToAdd = 3;
+        else if (dayOfWeek == DayOfWeek.SATURDAY)
+            daysToAdd = 2;
+        else
+            daysToAdd = 1;
+        return today.plusDays(daysToAdd);
+    });
+}

core-java/src/test/java/com/baeldung/temporaladjusters/TemporalAdjustersTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.temporaladjusters;
+
+import java.text.SimpleDateFormat;
+import java.time.DayOfWeek;
+import java.time.LocalDate;
+import java.time.temporal.TemporalAdjusters;
+import java.util.Calendar;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.baeldung.temporaladjuster.TemporalAdjusterUtil;
+
+public class TemporalAdjustersTest {
+
+    @Test
+    public void whenAdjust_thenNextSunday() {
+        LocalDate localDate = LocalDate.now();
+        LocalDate nextSunday = localDate.with(TemporalAdjusters.next(DayOfWeek.SUNDAY));
+
+        Calendar calendar = TemporalAdjusterUtil.nextDayOfWeek(Calendar.SUNDAY);
+        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
+        format.setCalendar(calendar);
+        String formattedDate = format.format(calendar.getTime());
+
+        Assert.assertEquals(formattedDate, nextSunday.toString());
+    }
+
+}

libraries/src/test/java/com/baeldung/text/StrBuilderTest.java

@@ -5,12 +5,12 @@ import org.junit.Assert;
 import org.junit.Test;
 
 public class StrBuilderTest {
-    
+
     @Test
     public void whenReplaced_thenCorrect() {
         StrBuilder strBuilder = new StrBuilder("example StrBuilder!");
         strBuilder.replaceAll("example", "new");
-        
+
         Assert.assertEquals(new StrBuilder("new StrBuilder!"), strBuilder);
     }
     
@@ -21,4 +21,4 @@ public class StrBuilderTest {
         
         Assert.assertEquals(new StrBuilder(""), strBuilder);
     }
-}
+}