Fix for Date formatting not including timezone #149

Author: germanattanasio

src/main/java/com/ibm/watson/developer_cloud/util/DateDeserializer.java

@@ -0,0 +1,41 @@
+package com.ibm.watson.developer_cloud.util;
+
+import java.lang.reflect.Type;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParseException;
+
+public class DateDeserializer implements JsonDeserializer<Date> {
+  private static final String DATE_UTC = "yyyy-MM-dd'T'HH:mm:ss.SSS";
+  private static final String DATE_WITHOUT_SECONDS = "yyyy-MM-dd'T'HH:mm:ssZ";
+  private static final SimpleDateFormat utc = new SimpleDateFormat(DATE_UTC);
+  private static final SimpleDateFormat utcWithoutSec = new SimpleDateFormat(DATE_WITHOUT_SECONDS);
+
+  private static final Logger log = Logger.getLogger(DateDeserializer.class.getName());
+
+  @Override
+  public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
+      throws JsonParseException {
+
+    String dateAsString = json.getAsJsonPrimitive().getAsString();
+    dateAsString = dateAsString.replaceAll("Z$", "+0000");
+    try {
+      return utc.parse(dateAsString);
+    } catch (Exception e1) {
+      try {
+        return utcWithoutSec.parse(dateAsString);
+      } catch (ParseException e2) {
+        log.log(Level.SEVERE, "Error parsing: " + dateAsString, e2);
+      }
+    }
+    return null;
+  }
+
+}

src/main/java/com/ibm/watson/developer_cloud/util/DateSerializer.java

@@ -0,0 +1,31 @@
+package com.ibm.watson.developer_cloud.util;
+
+import java.lang.reflect.Type;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+
+/**
+ * DateSerializer
+ */
+public class DateSerializer implements JsonSerializer<Date> {
+  private static final String DATE_FORMAT_UTC = "yyyy-MM-dd'T'HH:mm:ss.SSSZ";
+
+  /*
+   * (non-Javadoc)
+   * 
+   * @see com.google.gson.JsonSerializer#serialize(java.lang.Object, java.lang.reflect.Type,
+   * com.google.gson.JsonSerializationContext)
+   */
+  @Override
+  public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
+    SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT_UTC);
+
+    return src == null ? null : new JsonPrimitive(sdf.format(src));
+  }
+
+}

src/main/java/com/ibm/watson/developer_cloud/util/GsonSingleton.java

@@ -13,6 +13,8 @@
  */
 package com.ibm.watson.developer_cloud.util;
 
+import java.util.Date;
+
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 
@@ -22,17 +24,22 @@
  */
 public class GsonSingleton {
 
-  private static final String DATE_FORMAT_UTC = "yyyy-MM-dd'T'HH:mm:ss.SSS";
   private static Gson gson;
 
   /**
    * Creates a {@link com.google.gson.Gson} object that can be use to serialize and deserialize Java
-   * objects}
+   * objects
    * 
-   * @return the Gson
+   * @return the {@link Gson}
    */
   private static Gson createGson() {
-    return new GsonBuilder().setPrettyPrinting().setDateFormat(DATE_FORMAT_UTC).create();
+    GsonBuilder builder = new GsonBuilder().setPrettyPrinting();
+
+    // Date serializer and deserializer
+    builder.registerTypeAdapter(Date.class, new DateDeserializer());
+    builder.registerTypeAdapter(Date.class, new DateSerializer());
+
+    return builder.create();
   }
 
   /**

src/test/java/com/ibm/watson/developer_cloud/util/GsonSingletonTest.java

@@ -0,0 +1,37 @@
+package com.ibm.watson.developer_cloud.util;
+
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.google.gson.reflect.TypeToken;
+
+/**
+ * Test the {@link GsonSingleton} class used to transform from and to JSON
+ */
+public class GsonSingletonTest {
+  Type listType = new TypeToken<ArrayList<Date>>() {}.getType();
+
+  /**
+   * Test the date serializer and deserializer
+   */
+  @Test
+  public void testDateSerializer() {
+    String dateAsJson =
+        "[\"2014-06-04T15:38:07Z\"," + "\"2015-08-24T18:42:25.324Z\","
+            + "\"2015-08-24T18:42:25.324Z\"," + "\"2015-08-31T00:49:27.77Z\","
+            + "\"2015-09-01T16:05:30.058-0400\"," + "\"2015-09-01T16:05:30.058-0400\","
+            + "\"2015-09-01T16:05:30.058-0400\"," + "\"2015-09-01T16:05:30.058-0400\","
+            + "\"2015-10-08T17:59:39.609Z\"]";
+
+    List<Date> dates = GsonSingleton.getGson().fromJson(dateAsJson, listType);
+    Assert.assertNotNull(dates);
+
+    String datesAsString = GsonSingleton.getGson().toJson(dates);
+    Assert.assertNotNull(datesAsString);
+  }
+}