DATACOUCH-69 - Support for Date and Calendar conversions.

This changeset adds aut of the box support for date and calendar objects.
They get converted to simple longs (unix timestamps) and back, since couchbase
server views have good support for those through the dateToArray() function.

A custom converter takes precedence though to customize these conversions.

src/main/java/org/springframework/data/couchbase/core/convert/CustomConversions.java

@@ -81,7 +81,7 @@ public class CustomConversions {
 
     this.converters = new ArrayList<Object>();
     this.converters.addAll(converters);
-    this.converters.addAll(JodaTimeConverters.getConvertersToRegister());
+    this.converters.addAll(DateConverters.getConvertersToRegister());
 
     for (Object converter : this.converters) {
       registerConversion(converter);

src/main/java/org/springframework/data/couchbase/core/convert/DateConverters.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2014 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.data.couchbase.core.convert;
+
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.convert.ReadingConverter;
+import org.springframework.data.convert.WritingConverter;
+
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.Collection;
+import java.util.Date;
+import java.util.List;
+
+/**
+ * Out of the box conversions for java dates and calendars.
+ *
+ * @author Michael Nitschinger
+ */
+public final class DateConverters {
+
+  private DateConverters() {}
+
+  public static Collection<Converter<?, ?>> getConvertersToRegister() {
+    List<Converter<?, ?>> converters = new ArrayList<Converter<?, ?>>();
+    converters.add(DateToLongConverter.INSTANCE);
+    converters.add(CalendarToLongConverter.INSTANCE);
+
+    converters.add(LongToDateConverter.INSTANCE);
+    converters.add(LongToCalendarConverter.INSTANCE);
+    return converters;
+  }
+
+  @WritingConverter
+  public enum DateToLongConverter implements Converter<Date, Long> {
+    INSTANCE;
+
+    @Override
+    public Long convert(Date source) {
+      return source.getTime();
+    }
+  }
+
+  @WritingConverter
+  public enum CalendarToLongConverter implements Converter<Calendar, Long> {
+    INSTANCE;
+
+    @Override
+    public Long convert(Calendar source) {
+      return source.getTimeInMillis() / 1000;
+    }
+  }
+
+  @ReadingConverter
+  public enum LongToDateConverter implements Converter<Long, Date> {
+    INSTANCE;
+
+    @Override
+    public Date convert(Long source) {
+      Date date = new Date();
+      date.setTime(source);
+      return date;
+    }
+  }
+
+  @ReadingConverter
+  public enum LongToCalendarConverter implements Converter<Long, Calendar> {
+    INSTANCE;
+
+    @Override
+    public Calendar convert(Long source) {
+      Calendar calendar = Calendar.getInstance();
+      calendar.setTimeInMillis(source * 1000);
+      return calendar;
+    }
+  }
+
+}