Implemented a ZonedDateTime-to-GregorianCalendar converter

diff --git a/src/main/java/de/juplo/jpa/converters/ZonedDateTimeConverter.java b/src/main/java/de/juplo/jpa/converters/ZonedDateTimeConverter.java
new file mode 100644 (file)
index 0000000..de9b726
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+++ b/src/main/java/de/juplo/jpa/converters/ZonedDateTimeConverter.java
@@ -0,0 +1,33 @@
+package de.juplo.jpa.converters;
+
+import java.time.ZonedDateTime;
+import java.util.GregorianCalendar;
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+
+
+/**
+ * Converts a {@link ZonedDateTime} to a {@link GregorianCalendar}, as suggested
+ * in the official Java 8 Time tutorial.
+ * <p>
+ * The {@link GregorianCalendar} can then be persisted as
+ * {@link java.persistene.TemporalType.TIMESTAMP} with the help of the
+ * {@link java.persist.Tmporal}-annotation.
+ * @see https://docs.oracle.com/javase/tutorial/datetime/iso/legacy.html
+ * @author Kai Moritz
+ */
+@Converter(autoApply = true)
+public class ZonedDateTimeConverter implements AttributeConverter<ZonedDateTime, GregorianCalendar>
+{
+  @Override
+  public GregorianCalendar convertToDatabaseColumn(ZonedDateTime zdt)
+  {
+    return GregorianCalendar.from(zdt);
+  }
+
+  @Override
+  public ZonedDateTime convertToEntityAttribute(GregorianCalendar calendar)
+  {
+    return calendar.toZonedDateTime();
+  }
+}