Add gson adapters for special field types

Added type adapters for Instant, LocalDateTime, and ZonedDateTime.  UUID
seems to work already.
Added new Coder that offers an alternative encoding for Instant.

Issue-ID: POLICY-1625
Signed-off-by: Jim Hahn <jrh3@att.com>
Change-Id: I5230fa7fe955d78c5f2da1316cb1504b5875ea84

1 files changed, 64 insertions, 0 deletions

diff --git a/gson/src/main/java/org/onap/policy/common/gson/ZonedDateTimeTypeAdapter.java b/gson/src/main/java/org/onap/policy/common/gson/ZonedDateTimeTypeAdapter.java
new file mode 100644
index 00000000..147fb03d
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/ZonedDateTimeTypeAdapter.java
@@ -0,0 +1,64 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2020 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson;
+
+import com.google.gson.JsonParseException;
+import com.google.gson.TypeAdapter;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+
+/**
+ * GSON Type Adapter for "ZonedDateTime" fields, that uses the standard
+ * ISO_ZONED_DATE_TIME formatter.
+ */
+public class ZonedDateTimeTypeAdapter extends TypeAdapter<ZonedDateTime> {
+    private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ISO_ZONED_DATE_TIME;
+
+    @Override
+    public ZonedDateTime read(JsonReader in) throws IOException {
+        try {
+            if (in.peek() == JsonToken.NULL) {
+                in.nextNull();
+                return null;
+            } else {
+                return ZonedDateTime.parse(in.nextString(), FORMATTER);
+            }
+
+        } catch (DateTimeParseException e) {
+            throw new JsonParseException("invalid date", e);
+        }
+    }
+
+    @Override
+    public void write(JsonWriter out, ZonedDateTime value) throws IOException {
+        if (value == null) {
+            out.nullValue();
+        } else {
+            String text = value.format(FORMATTER);
+            out.value(text);
+        }
+    }
+}