Merge remote-tracking branch 'upstream/master'

2017-11-22 00:54:56 -03:00
parent d20693e31b ea64def1ae
commit 19a9077274
652 changed files with 5538 additions and 280 deletions
@@ -0,0 +1,5 @@
+package com.baeldung.annotations;
+
+@Deprecated
+class ClassWithAnnotation {
+}
@@ -0,0 +1,9 @@
+package com.baeldung.annotations;
+
+class ClassWithDeprecatedMethod {
+
+    @Deprecated
+    static void deprecatedMethod() {
+
+    }
+}
@@ -0,0 +1,11 @@
+package com.baeldung.annotations;
+
+class ClassWithSafeVarargs<T> {
+
+    @SafeVarargs
+    final void iterateOverVarargs(T... args) {
+        for (T x : args) {
+            // do stuff with x
+        }
+    }
+}
@@ -0,0 +1,9 @@
+package com.baeldung.annotations;
+
+class ClassWithSuppressWarnings {
+
+    @SuppressWarnings("deprecation")
+    void useDeprecatedMethod() {
+        ClassWithDeprecatedMethod.deprecatedMethod(); // no warning is generated here
+    }
+}
@@ -0,0 +1,8 @@
+package com.baeldung.annotations;
+
+@FunctionalInterface
+interface IntConsumer {
+
+    void accept(Integer number);
+
+}
@@ -0,0 +1,8 @@
+package com.baeldung.annotations;
+
+import java.lang.annotation.Repeatable;
+
+@Repeatable(Intervals.class)
+@interface Interval {
+    int hour() default 1;
+}
@@ -0,0 +1,9 @@
+package com.baeldung.annotations;
+
+public class IntervalUsage {
+
+    @Interval(hour = 17)
+    @Interval(hour = 13)
+    void doPeriodicCleanup() {
+    }
+}
@@ -0,0 +1,5 @@
+package com.baeldung.annotations;
+
+@interface Intervals {
+    Interval[] value();
+}
@@ -0,0 +1,11 @@
+package com.baeldung.annotations;
+
+import java.lang.annotation.*;
+
+@Inherited
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.LOCAL_VARIABLE, ElementType.FIELD})
+@interface MyAnnotation {
+
+}
@@ -0,0 +1,16 @@
+package com.baeldung.annotations;
+
+class MyAnnotationTarget {
+
+    // this is OK
+    @MyAnnotation
+    String someField;
+
+    // @MyAnnotation <- this is invalid usage!
+    void doSomething() {
+
+        // this also works
+        @MyAnnotation
+        String localVariable;
+    }
+}
@@ -0,0 +1,6 @@
+package com.baeldung.annotations;
+
+interface MyOperation {
+
+    void perform();
+}
@@ -0,0 +1,9 @@
+package com.baeldung.annotations;
+
+class MyOperationImpl implements MyOperation {
+
+    @Override
+    public void perform() {
+
+    }
+}
@@ -0,0 +1,35 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.ZoneId;
+import java.util.Date;
+
+/**
+ * Class which shows different ways of converting java.util.Date into java.time.LocalDate.
+ * 
+ * @author abialas
+ *
+ */
+public class DateToLocalDateConverter {
+
+    public static LocalDate convertToLocalDateViaInstant(Date dateToConvert) {
+        return dateToConvert.toInstant()
+            .atZone(ZoneId.systemDefault())
+            .toLocalDate();
+    }
+
+    public static LocalDate convertToLocalDateViaSqlDate(Date dateToConvert) {
+        return new java.sql.Date(dateToConvert.getTime()).toLocalDate();
+    }
+
+    public static LocalDate convertToLocalDateViaMilisecond(Date dateToConvert) {
+        return Instant.ofEpochMilli(dateToConvert.getTime())
+            .atZone(ZoneId.systemDefault())
+            .toLocalDate();
+    }
+
+}
@@ -0,0 +1,35 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.Date;
+
+/**
+ * Class which shows different ways of converting java.util.Date into java.time.LocalDateTime. 
+ * 
+ * @author abialas
+ *
+ */
+public class DateToLocalDateTimeConverter {
+
+    public static LocalDateTime convertToLocalDateTimeViaInstant(Date dateToConvert) {
+        return dateToConvert.toInstant()
+            .atZone(ZoneId.systemDefault())
+            .toLocalDateTime();
+    }
+
+    public static LocalDateTime convertToLocalDateTimeViaSqlTimestamp(Date dateToConvert) {
+        return new java.sql.Timestamp(dateToConvert.getTime()).toLocalDateTime();
+    }
+
+    public static LocalDateTime convertToLocalDateTimeViaMilisecond(Date dateToConvert) {
+        return Instant.ofEpochMilli(dateToConvert.getTime())
+            .atZone(ZoneId.systemDefault())
+            .toLocalDateTime();
+    }
+
+}
@@ -0,0 +1,27 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.Date;
+
+/**
+ * Class which shows different ways of converting java.time.LocalDateTime into java.util.Date. 
+ *  
+ * @author abialas
+ *
+ */
+public class LocalDateTimeToDateConverter {
+
+    public static Date convertToDateViaSqlTimestamp(LocalDateTime dateToConvert) {
+        return java.sql.Timestamp.valueOf(dateToConvert);
+    }
+
+    public static Date convertToDateViaInstant(LocalDateTime dateToConvert) {
+        return java.util.Date.from(dateToConvert.atZone(ZoneId.systemDefault())
+            .toInstant());
+    }
+
+}
@@ -0,0 +1,28 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import java.time.LocalDate;
+import java.time.ZoneId;
+import java.util.Date;
+
+/**
+ * Class which shows different ways of converting java.time.LocalDate into java.util.Date. 
+ *  
+ * @author abialas
+ *
+ */
+public class LocalDateToDateConverter {
+
+    public static Date convertToDateViaSqlDate(LocalDate dateToConvert) {
+        return java.sql.Date.valueOf(dateToConvert);
+    }
+
+    public static Date convertToDateViaInstant(LocalDate dateToConvert) {
+        return java.util.Date.from(dateToConvert.atStartOfDay()
+            .atZone(ZoneId.systemDefault())
+            .toInstant());
+    }
+
+}
@@ -0,0 +1,55 @@
+package com.baeldung.timezonedisplay;
+
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+public class TimezoneDisplay {
+
+    public enum OffsetBase {
+        GMT, UTC
+    }
+
+    public List<String> getTimeZoneList(OffsetBase base) {
+        Set<String> availableZoneIds = ZoneId.getAvailableZoneIds();
+
+        LocalDateTime now = LocalDateTime.now();
+        return availableZoneIds
+          .stream()
+          .map(ZoneId::of)
+          .sorted(new ZoneComparator())
+          .map(id -> String.format("(%s%s) %s", base, getOffset(now, id), id.getId()))
+          .collect(Collectors.toList());
+    }
+
+    private String getOffset(LocalDateTime dateTime, ZoneId id) {
+        return dateTime
+          .atZone(id)
+          .getOffset()
+          .getId()
+          .replace("Z", "+00:00");
+    }
+
+    private class ZoneComparator implements Comparator<ZoneId> {
+
+        @Override
+        public int compare(ZoneId zoneId1, ZoneId zoneId2) {
+            LocalDateTime now = LocalDateTime.now();
+
+            ZoneOffset offset1 = now
+              .atZone(zoneId1)
+              .getOffset();
+
+            ZoneOffset offset2 = now
+              .atZone(zoneId2)
+              .getOffset();
+
+            return offset1.compareTo(offset2);
+        }
+    }
+
+}
@@ -0,0 +1,18 @@
+package com.baeldung.timezonedisplay;
+
+import java.util.List;
+
+public class TimezoneDisplayApp {
+
+    public static void main(String... args) {
+        TimezoneDisplay display = new TimezoneDisplay();
+
+        System.out.println("Time zones in UTC:");
+        List<String> utc = display.getTimeZoneList(TimezoneDisplay.OffsetBase.UTC);
+        utc.forEach(System.out::println);
+
+        System.out.println("Time zones in GMT:");
+        List<String> gmt = display.getTimeZoneList(TimezoneDisplay.OffsetBase.GMT);
+        gmt.forEach(System.out::println);
+    }
+}
@@ -0,0 +1,72 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import static org.junit.Assert.assertEquals;
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoField;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.junit.Test;
+
+/**
+ * 
+ * JUnits for {@link DateToLocalDateConverter} class.
+ * 
+ * @author abialas
+ *
+ */
+public class DateToLocalDateConverterTest {
+
+    @Test
+    public void shouldReturn10thNovember2010WhenConvertViaInstant() {
+        // given
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(2010, 10, 10);
+        Date dateToConvert = calendar.getTime();
+
+        // when
+        LocalDate localDate = DateToLocalDateConverter.convertToLocalDateViaInstant(dateToConvert);
+
+        // then
+        assertEquals(2010, localDate.get(ChronoField.YEAR));
+        assertEquals(11, localDate.get(ChronoField.MONTH_OF_YEAR));
+        assertEquals(10, localDate.get(ChronoField.DAY_OF_MONTH));
+    }
+
+    @Test
+    public void shouldReturn10thNovember2010WhenConvertViaMiliseconds() {
+        // given
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(2010, 10, 10);
+        Date dateToConvert = calendar.getTime();
+
+        // when
+        LocalDate localDate = DateToLocalDateConverter.convertToLocalDateViaMilisecond(dateToConvert);
+
+        // then
+        assertEquals(2010, localDate.get(ChronoField.YEAR));
+        assertEquals(11, localDate.get(ChronoField.MONTH_OF_YEAR));
+        assertEquals(10, localDate.get(ChronoField.DAY_OF_MONTH));
+    }
+
+    @Test
+    public void shouldReturn10thNovember2010WhenConvertViaSqlDate() {
+        // given
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(2010, 10, 10);
+        Date dateToConvert = calendar.getTime();
+
+        // when
+        LocalDate localDate = DateToLocalDateConverter.convertToLocalDateViaSqlDate(dateToConvert);
+
+        // then
+        assertEquals(2010, localDate.get(ChronoField.YEAR));
+        assertEquals(11, localDate.get(ChronoField.MONTH_OF_YEAR));
+        assertEquals(10, localDate.get(ChronoField.DAY_OF_MONTH));
+    }
+
+}
@@ -0,0 +1,78 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import static org.junit.Assert.assertEquals;
+
+import java.time.LocalDateTime;
+import java.time.temporal.ChronoField;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.junit.Test;
+
+/**
+ * 
+ * JUnits for {@link DateToLocalDateTimeConverter} class.
+ * 
+ * @author abialas
+ *
+ */
+public class DateToLocalDateTimeConverterTest {
+
+    @Test
+    public void shouldReturn10thNovember2010time8hour20minWhenConvertViaInstant() {
+        // given
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(2010, 10, 10, 8, 20);
+        Date dateToConvert = calendar.getTime();
+
+        // when
+        LocalDateTime localDateTime = DateToLocalDateTimeConverter.convertToLocalDateTimeViaInstant(dateToConvert);
+
+        // then
+        assertEquals(2010, localDateTime.get(ChronoField.YEAR));
+        assertEquals(11, localDateTime.get(ChronoField.MONTH_OF_YEAR));
+        assertEquals(10, localDateTime.get(ChronoField.DAY_OF_MONTH));
+        assertEquals(8, localDateTime.get(ChronoField.HOUR_OF_DAY));
+        assertEquals(20, localDateTime.get(ChronoField.MINUTE_OF_HOUR));
+    }
+
+    @Test
+    public void shouldReturn10thNovember2010time8hour20minWhenConvertViaMiliseconds() {
+        // given
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(2010, 10, 10, 8, 20);
+        Date dateToConvert = calendar.getTime();
+
+        // when
+        LocalDateTime localDateTime = DateToLocalDateTimeConverter.convertToLocalDateTimeViaMilisecond(dateToConvert);
+
+        // then
+        assertEquals(2010, localDateTime.get(ChronoField.YEAR));
+        assertEquals(11, localDateTime.get(ChronoField.MONTH_OF_YEAR));
+        assertEquals(10, localDateTime.get(ChronoField.DAY_OF_MONTH));
+        assertEquals(8, localDateTime.get(ChronoField.HOUR_OF_DAY));
+        assertEquals(20, localDateTime.get(ChronoField.MINUTE_OF_HOUR));
+    }
+
+    @Test
+    public void shouldReturn10thNovember2010time8hour20minWhenConvertViaSqlTimestamp() {
+        // given
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(2010, 10, 10, 8, 20);
+        Date dateToConvert = calendar.getTime();
+
+        // when
+        LocalDateTime localDateTime = DateToLocalDateTimeConverter.convertToLocalDateTimeViaSqlTimestamp(dateToConvert);
+
+        // then
+        assertEquals(2010, localDateTime.get(ChronoField.YEAR));
+        assertEquals(11, localDateTime.get(ChronoField.MONTH_OF_YEAR));
+        assertEquals(10, localDateTime.get(ChronoField.DAY_OF_MONTH));
+        assertEquals(8, localDateTime.get(ChronoField.HOUR_OF_DAY));
+        assertEquals(20, localDateTime.get(ChronoField.MINUTE_OF_HOUR));
+    }
+
+}
@@ -0,0 +1,61 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import static org.junit.Assert.assertEquals;
+
+import java.time.LocalDateTime;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.junit.Test;
+
+/**
+ * 
+ * JUnits for {@link LocalDateTimeToDateConverter} class.
+ * 
+ * @author abialas
+ *
+ */
+public class LocalDateTimeToDateConverterTest {
+
+    @Test
+    public void shouldReturn10thNovember2010time8hour20minWhenConvertViaInstant() {
+        // given
+        LocalDateTime dateToConvert = LocalDateTime.of(2010, 11, 10, 8, 20);
+
+        // when
+        Date date = LocalDateTimeToDateConverter.convertToDateViaInstant(dateToConvert);
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        // then
+        assertEquals(2010, calendar.get(Calendar.YEAR));
+        assertEquals(10, calendar.get(Calendar.MONTH));
+        assertEquals(10, calendar.get(Calendar.DAY_OF_MONTH));
+        assertEquals(8, calendar.get(Calendar.HOUR));
+        assertEquals(20, calendar.get(Calendar.MINUTE));
+        assertEquals(0, calendar.get(Calendar.SECOND));
+    }
+
+    @Test
+    public void shouldReturn10thNovember2010WhenConvertViaSqlTimestamp() {
+        // given
+        LocalDateTime dateToConvert = LocalDateTime.of(2010, 11, 10, 8, 20);
+
+        // when
+        Date date = LocalDateTimeToDateConverter.convertToDateViaSqlTimestamp(dateToConvert);
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        // then
+        assertEquals(2010, calendar.get(Calendar.YEAR));
+        assertEquals(10, calendar.get(Calendar.MONTH));
+        assertEquals(10, calendar.get(Calendar.DAY_OF_MONTH));
+        assertEquals(8, calendar.get(Calendar.HOUR));
+        assertEquals(20, calendar.get(Calendar.MINUTE));
+        assertEquals(0, calendar.get(Calendar.SECOND));
+    }
+
+}
@@ -0,0 +1,55 @@
+/**
+ * 
+ */
+package com.baeldung.datetime;
+
+import static org.junit.Assert.assertEquals;
+
+import java.time.LocalDate;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.junit.Test;
+
+/**
+ * 
+ * JUnits for {@link LocalDateToDateConverter} class.
+ * 
+ * @author abialas
+ *
+ */
+public class LocalDateToDateConverterTest {
+
+    @Test
+    public void shouldReturn10thNovember2010WhenConvertViaInstant() {
+        // given
+        LocalDate dateToConvert = LocalDate.of(2010, 11, 10);
+
+        // when
+        Date date = LocalDateToDateConverter.convertToDateViaInstant(dateToConvert);
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        // then
+        assertEquals(2010, calendar.get(Calendar.YEAR));
+        assertEquals(10, calendar.get(Calendar.MONTH));
+        assertEquals(10, calendar.get(Calendar.DAY_OF_MONTH));
+    }
+
+    @Test
+    public void shouldReturn10thNovember2010WhenConvertViaSqlDate() {
+        // given
+        LocalDate dateToConvert = LocalDate.of(2010, 11, 10);
+
+        // when
+        Date date = LocalDateToDateConverter.convertToDateViaSqlDate(dateToConvert);
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        // then
+        assertEquals(2010, calendar.get(Calendar.YEAR));
+        assertEquals(10, calendar.get(Calendar.MONTH));
+        assertEquals(10, calendar.get(Calendar.DAY_OF_MONTH));
+    }
+
+}