DATACMNS-773 - Added support for persisting ZoneId instances as Strings.

We now ship converters for JSR-310 and ThreeTenBP's ZoneId conversion to String and back.

src/main/java/org/springframework/data/convert/Jsr310Converters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2014 the original author or authors.
+ * Copyright 2013-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
+import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -63,6 +64,8 @@ public abstract class Jsr310Converters {
 		converters.add(LocalTimeToDateConverter.INSTANCE);
 		converters.add(DateToInstantConverter.INSTANCE);
 		converters.add(InstantToDateConverter.INSTANCE);
+		converters.add(ZoneIdToStringConverter.INSTANCE);
+		converters.add(StringToZoneIdConverter.INSTANCE);
 
 		return converters;
 	}
@@ -156,4 +159,26 @@ public abstract class Jsr310Converters {
 			return source == null ? null : Date.from(source.atZone(systemDefault()).toInstant());
 		}
 	}
+
+	@WritingConverter
+	public static enum ZoneIdToStringConverter implements Converter<ZoneId, String> {
+
+		INSTANCE;
+
+		@Override
+		public String convert(ZoneId source) {
+			return source.toString();
+		}
+	}
+
+	@ReadingConverter
+	public static enum StringToZoneIdConverter implements Converter<String, ZoneId> {
+
+		INSTANCE;
+
+		@Override
+		public ZoneId convert(String source) {
+			return ZoneId.of(source);
+		}
+	}
 }

src/main/java/org/springframework/data/convert/ThreeTenBackPortConverters.java

@@ -33,6 +33,7 @@ import org.threeten.bp.Instant;
 import org.threeten.bp.LocalDate;
 import org.threeten.bp.LocalDateTime;
 import org.threeten.bp.LocalTime;
+import org.threeten.bp.ZoneId;
 
 /**
  * Helper class to register {@link Converter} implementations for the ThreeTen Backport project in case it's present on
@@ -67,6 +68,8 @@ public abstract class ThreeTenBackPortConverters {
 		converters.add(LocalTimeToDateConverter.INSTANCE);
 		converters.add(DateToInstantConverter.INSTANCE);
 		converters.add(InstantToDateConverter.INSTANCE);
+		converters.add(ZoneIdToStringConverter.INSTANCE);
+		converters.add(StringToZoneIdConverter.INSTANCE);
 
 		return converters;
 	}
@@ -161,4 +164,26 @@ public abstract class ThreeTenBackPortConverters {
 			return source == null ? null : toDate(source.atZone(systemDefault()).toInstant());
 		}
 	}
+
+	@WritingConverter
+	public static enum ZoneIdToStringConverter implements Converter<ZoneId, String> {
+
+		INSTANCE;
+
+		@Override
+		public String convert(ZoneId source) {
+			return source.toString();
+		}
+	}
+
+	@ReadingConverter
+	public static enum StringToZoneIdConverter implements Converter<String, ZoneId> {
+
+		INSTANCE;
+
+		@Override
+		public ZoneId convert(String source) {
+			return ZoneId.of(source);
+		}
+	}
 }

src/test/java/org/springframework/data/convert/Jsr310ConvertersUnitTests.java

@@ -23,7 +23,11 @@ import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
+import java.time.ZoneId;
 import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
 
 import org.junit.Test;
 import org.springframework.core.convert.ConversionService;
@@ -126,6 +130,19 @@ public class Jsr310ConvertersUnitTests {
 		assertThat(CONVERSION_SERVICE.convert(now.toInstant(), Date.class), is(now));
 	}
 
+	@Test
+	public void convertsZoneIdToStringAndBack() {
+
+		Map<String, ZoneId> ids = new HashMap<String, ZoneId>();
+		ids.put("Europe/Berlin", ZoneId.of("Europe/Berlin"));
+		ids.put("+06:00", ZoneId.of("+06:00"));
+
+		for (Entry<String, ZoneId> entry : ids.entrySet()) {
+			assertThat(CONVERSION_SERVICE.convert(entry.getValue(), String.class), is(entry.getKey()));
+			assertThat(CONVERSION_SERVICE.convert(entry.getKey(), ZoneId.class), is(entry.getValue()));
+		}
+	}
+
 	private static String format(Date date, String format) {
 		return new SimpleDateFormat(format).format(date);
 	}

src/test/java/org/springframework/data/convert/ThreeTenBackPortConvertersUnitTests.java

@@ -21,6 +21,9 @@ import static org.threeten.bp.DateTimeUtils.*;
 
 import java.text.SimpleDateFormat;
 import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
 
 import org.junit.Test;
 import org.springframework.core.convert.ConversionService;
@@ -30,12 +33,13 @@ import org.threeten.bp.Instant;
 import org.threeten.bp.LocalDate;
 import org.threeten.bp.LocalDateTime;
 import org.threeten.bp.LocalTime;
+import org.threeten.bp.ZoneId;
 
 /**
  * Unit tests for {@link ThreeTenBackPortConverters}.
  * 
  * @author Oliver Gierke
- * @ssince 1.10
+ * @since 1.10
  */
 public class ThreeTenBackPortConvertersUnitTests {
 
@@ -128,6 +132,19 @@ public class ThreeTenBackPortConvertersUnitTests {
 		assertThat(CONVERSION_SERVICE.convert(toInstant(now), Date.class), is(now));
 	}
 
+	@Test
+	public void convertsZoneIdToStringAndBack() {
+
+		Map<String, ZoneId> ids = new HashMap<String, ZoneId>();
+		ids.put("Europe/Berlin", ZoneId.of("Europe/Berlin"));
+		ids.put("+06:00", ZoneId.of("+06:00"));
+
+		for (Entry<String, ZoneId> entry : ids.entrySet()) {
+			assertThat(CONVERSION_SERVICE.convert(entry.getValue(), String.class), is(entry.getKey()));
+			assertThat(CONVERSION_SERVICE.convert(entry.getKey(), ZoneId.class), is(entry.getValue()));
+		}
+	}
+
 	private static String format(Date date, String format) {
 		return new SimpleDateFormat(format).format(date);
 	}