Add ZoneId converter

.gitignore

@@ -8,6 +8,8 @@ target
 .idea/libraries/
 .idea/scala_settings.xml
 .idea/dictionaries/
+*.ipr
+*.iws
 
 # Mac
 .DS_Store

src/main/java/com/fatboyindustrial/gsonjavatime/Converters.java

@@ -33,6 +33,7 @@
 import java.time.LocalTime;
 import java.time.OffsetDateTime;
 import java.time.OffsetTime;
+import java.time.ZoneId;
 import java.time.ZonedDateTime;
 
 /**
@@ -62,6 +63,9 @@ public class Converters
   /** The specific genericized type for {@code Instant}. */
   public static final Type INSTANT_TYPE = new TypeToken<Instant>(){}.getType();
 
+  /** The specific genericized type for {@code ZoneId}. */
+  public static final Type ZONE_ID_TYPE = new TypeToken<ZoneId>(){}.getType();
+
   /**
    * Registers all the Java Time converters.
    * @param builder The GSON builder to register the converters with.
@@ -78,6 +82,7 @@ public static GsonBuilder registerAll(GsonBuilder builder)
     registerOffsetTime(builder);
     registerZonedDateTime(builder);
     registerInstant(builder);
+    registerZoneId(builder);
 
     return builder;
   }
@@ -162,7 +167,19 @@ public static GsonBuilder registerZonedDateTime(GsonBuilder builder)
   public static GsonBuilder registerInstant(GsonBuilder builder)
   {
     builder.registerTypeAdapter(INSTANT_TYPE, new InstantConverter());
-    
+
     return builder;
   }
+
+    /**
+     * Registers the {@link ZoneIdConverter} converter.
+     * @param builder The GSON builder to register the converter with.
+     * @return A reference to {@code builder}.
+     */
+   public static GsonBuilder registerZoneId(GsonBuilder builder)
+   {
+     builder.registerTypeAdapter(ZONE_ID_TYPE, new ZoneIdConverter());
+
+     return builder;
+   }
 }

src/main/java/com/fatboyindustrial/gsonjavatime/ZoneIdConverter.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright 2014 Greg Kopff
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.fatboyindustrial.gsonjavatime;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+
+import java.lang.reflect.Type;
+import java.time.ZoneId;
+
+/**
+ * GSON serialiser/deserialiser for converting {@link ZoneId} objects.
+ */
+public class ZoneIdConverter implements JsonSerializer<ZoneId>, JsonDeserializer<ZoneId> {
+
+    /**
+     * Gson invokes this call-back method during serialization when it encounters a field of the
+     * specified type. <p>
+     *
+     * In the implementation of this call-back method, you should consider invoking
+     * {@link JsonSerializationContext#serialize(Object, Type)} method to create JsonElements for any
+     * non-trivial field of the {@code src} object. However, you should never invoke it on the
+     * {@code src} object itself since that will cause an infinite loop (Gson will call your
+     * call-back method again).
+     *
+     * @param src the object that needs to be converted to Json.
+     * @param typeOfSrc the actual type (fully genericized version) of the source object.
+     * @return a JsonElement corresponding to the specified object.
+     */
+    @Override
+    public JsonElement serialize(final ZoneId src, final Type typeOfSrc, final JsonSerializationContext context)
+    {
+        if (src == null)
+        {
+            return null;
+        }
+        return new JsonPrimitive(src.getId());
+    }
+
+    /**
+     * Gson invokes this call-back method during deserialization when it encounters a field of the
+     * specified type. <p>
+     *
+     * In the implementation of this call-back method, you should consider invoking
+     * {@link JsonDeserializationContext#deserialize(JsonElement, Type)} method to create objects
+     * for any non-trivial field of the returned object. However, you should never invoke it on the
+     * the same type passing {@code json} since that will cause an infinite loop (Gson will call your
+     * call-back method again).
+     *
+     * @param json The Json data being deserialized
+     * @param typeOfT The type of the Object to deserialize to
+     * @return a deserialized object of the specified type typeOfT which is a subclass of {@code T}
+     * @throws JsonParseException if json is not in the expected format of {@code typeOfT}
+     */
+    @Override
+    public ZoneId deserialize(final JsonElement json, final Type typeOfT, final JsonDeserializationContext context) throws
+        JsonParseException
+    {
+        if (json == null)
+        {
+            return null;
+        }
+        if (json.isJsonNull())
+        {
+            return null;
+        }
+        final String zoneIdentifier = json.getAsString();
+        if (zoneIdentifier==null || zoneIdentifier.isEmpty())
+        {
+            return null;
+        }
+        return ZoneId.of(zoneIdentifier);
+    }
+}

src/test/java/com/fatboyindustrial/gsonjavatime/ConvertersTest.java

@@ -63,6 +63,7 @@ public void testSerialisation() throws Exception
     container.ot = OffsetTime.of(container.lt, ZoneOffset.ofHours(10));
     container.zdt = ZonedDateTime.of(container.ld, container.lt, ZoneId.of("Australia/Brisbane"));
     container.i = container.odt.toInstant();
+    container.zi = ZoneId.of("Australia/Brisbane");
 
     final String jsonString = gson.toJson(container);
     final JsonObject json = gson.fromJson(jsonString, JsonObject.class).getAsJsonObject();
@@ -74,6 +75,7 @@ public void testSerialisation() throws Exception
     assertThat(json.get("ot").getAsString(), is("12:56:00+10:00"));
     assertThat(json.get("zdt").getAsString(), is("1969-07-21T12:56:00+10:00[Australia/Brisbane]"));
     assertThat(json.get("i").getAsString(), is("1969-07-21T02:56:00Z"));
+    assertThat(json.get("zi").getAsString(), is("Australia/Brisbane"));
   }
 
   /**
@@ -92,6 +94,7 @@ public void testDeserialisation() throws Exception
     container.ot = OffsetTime.of(container.lt, ZoneOffset.ofHours(10));
     container.zdt = ZonedDateTime.of(container.ld, container.lt, ZoneId.of("Australia/Brisbane"));
     container.i = container.odt.toInstant();
+    container.zi = ZoneId.of("Australia/Brisbane");
 
     final JsonObject serialized = new JsonObject();
     serialized.add("ld", new JsonPrimitive("1969-07-21"));
@@ -101,6 +104,7 @@ public void testDeserialisation() throws Exception
     serialized.add("ot", new JsonPrimitive("12:56:00+10:00"));
     serialized.add("zdt", new JsonPrimitive("1969-07-21T12:56:00+10:00[Australia/Brisbane]"));
     serialized.add("i", new JsonPrimitive("1969-07-21T02:56:00Z"));
+    serialized.add("zi", new JsonPrimitive("Australia/Brisbane"));
 
     final String jsonString = gson.toJson(serialized);
     final Container deserialised = gson.fromJson(jsonString, Container.class);
@@ -112,6 +116,7 @@ public void testDeserialisation() throws Exception
     assertThat(deserialised.ot, is(container.ot));
     assertThat(deserialised.zdt, is(container.zdt));
     assertThat(deserialised.i, is(container.i));
+    assertThat(deserialised.zi, is(container.zi));
   }
 
   /**
@@ -126,5 +131,6 @@ private static class Container
     private OffsetTime ot;
     private ZonedDateTime zdt;
     private Instant i;
+    private ZoneId zi;
   }
 }

src/test/java/com/fatboyindustrial/gsonjavatime/ZoneIdConverterTest.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2014 Greg Kopff
+ * All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.fatboyindustrial.gsonjavatime;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.reflect.TypeToken;
+import org.junit.Test;
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
+
+import java.lang.reflect.Type;
+import java.time.ZoneId;
+import java.time.DateTimeException;
+
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Tests for {@link ZoneIdConverter}.
+ */
+public class ZoneIdConverterTest {
+
+    /** The specific genericized type for {@code ZoneId}. */
+    private static final Type ZONE_ID_TYPE = new TypeToken<ZoneId>(){}.getType();
+    @Rule
+    public ExpectedException exception = ExpectedException.none();
+
+    /**
+     * Tests that serialising to JSON works.
+     */
+    @Test
+    public void testSerialisation() throws Exception
+    {
+        final Gson gson = registerZoneId(new GsonBuilder()).create();
+
+        final ZoneId zoneId = ZoneId.of("Australia/Brisbane");
+        final String json= gson.toJson(zoneId, ZoneId.class);
+        assertThat(json, is("\"Australia/Brisbane\""));
+    }
+
+    /**
+     * Tests that deserialising from JSON works.
+     */
+    @Test
+    public void testDeserialisation() throws Exception
+    {
+        final Gson gson = registerZoneId(new GsonBuilder()).create();
+
+        final String json = "\"Australia/Brisbane\"";
+        final ZoneId zoneId = gson.fromJson(json, ZoneId.class);
+
+        assertThat(zoneId, is(ZoneId.of("Australia/Brisbane")));
+    }
+
+    /**
+     * Tests that deserialising from JSON works with an empty value.
+     */
+    @Test
+    public void testDeserialisationWithEmptyValue() throws Exception
+    {
+        final Gson gson = registerZoneId(new GsonBuilder()).create();
+
+        final String json = "\"\"";
+        final ZoneId zoneId = gson.fromJson(json, ZoneId.class);
+
+        assertNull(zoneId);
+    }
+
+    /**
+     * Tests that deserialising from JSON works with a whitespace.
+     */
+    @Test
+    public void testDeserialisationWithWhitespace() throws Exception
+    {
+        exception.expect(DateTimeException.class);
+        exception.expectMessage("Invalid ID for ZoneOffset, invalid format: ");
+
+        final Gson gson = registerZoneId(new GsonBuilder()).create();
+
+        final String json = "\" \"";
+        final ZoneId zoneId = gson.fromJson(json, ZoneId.class);
+    }
+
+    /**
+     * Registers the {@link ZoneIdConverter} converter.
+     * @param builder The GSON builder to register the converter with.
+     * @return A reference to {@code builder}.
+     */
+    private static GsonBuilder registerZoneId(GsonBuilder builder)
+    {
+        builder.registerTypeAdapter(ZONE_ID_TYPE, new ZoneIdConverter());
+
+        return builder;
+    }
+}