Don't map JSON values to Double

By default, gson treats all numbers as Double when placed into a
generic Map.  This is not backward compatible with existing policy
APIs.  Added a type adapter that walks Map objects and converts the
Double values to Integer or Long, where possible.
Made this the default behavior in the GsonMessageBodyHandler, the
JacksonHandler, and the StandardCoder.
Also fixed a couple of checkstyle errors in the gson project.

Change-Id: I9ac0c77e6592d1c039646f0662c077b77a1e9aaf
Issue-ID: POLICY-1542
Signed-off-by: Jim Hahn <jrh3@att.com>

1 files changed, 117 insertions, 0 deletions

diff --git a/gson/src/test/java/org/onap/policy/common/gson/MapDoubleAdapterFactoryTest.java b/gson/src/test/java/org/onap/policy/common/gson/MapDoubleAdapterFactoryTest.java
new file mode 100644
index 00000000..7171d262
--- /dev/null
+++ b/gson/src/test/java/org/onap/policy/common/gson/MapDoubleAdapterFactoryTest.java
@@ -0,0 +1,117 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 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 static org.junit.Assert.assertEquals;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import org.junit.Test;
+
+public class MapDoubleAdapterFactoryTest {
+    private static Gson gson = new GsonBuilder().registerTypeAdapterFactory(new MapDoubleAdapterFactory()).create();
+
+    @Test
+    @SuppressWarnings("unchecked")
+    public void test() {
+        MyMap map = new MyMap();
+        map.props = new HashMap<>();
+        map.props.put("plainString", "def");
+        map.props.put("posInt", 10);
+        map.props.put("negInt", -10);
+        map.props.put("doubleVal", 12.5);
+        map.props.put("posLong", 100000000000L);
+        map.props.put("negLong", -100000000000L);
+
+        Map<String, Object> nested = new LinkedHashMap<>();
+        map.props.put("nestedMap", nested);
+        nested.put("nestedString", "world");
+        nested.put("nestedInt", 50);
+
+        String json = gson.toJson(map);
+
+        map.props.clear();
+        map = gson.fromJson(json, MyMap.class);
+
+        assertEquals(json, gson.toJson(map));
+
+        assertEquals(10, map.props.get("posInt"));
+        assertEquals(-10, map.props.get("negInt"));
+        assertEquals(100000000000L, map.props.get("posLong"));
+        assertEquals(-100000000000L, map.props.get("negLong"));
+        assertEquals(12.5, map.props.get("doubleVal"));
+        assertEquals(nested, map.props.get("nestedMap"));
+
+        nested = (Map<String, Object>) map.props.get("nestedMap");
+        assertEquals(50, nested.get("nestedInt"));
+    }
+
+    @Test
+    public void test_ValueIsNotObject() {
+        MyDoubleMap map = new MyDoubleMap();
+        map.props = new LinkedHashMap<>();
+        map.props.put("plainDouble", 13.5);
+        map.props.put("doubleAsInt", 100.0);
+
+        String json = gson.toJson(map);
+
+        map.props.clear();
+        map = gson.fromJson(json, MyDoubleMap.class);
+
+        // everything should still be Double - check by simply accessing
+        map.props.get("plainDouble");
+        map.props.get("doubleAsInt");
+    }
+
+    @Test
+    public void test_KeyIsNotString() {
+        MyObjectMap map = new MyObjectMap();
+
+        map.props = new LinkedHashMap<>();
+        map.props.put("plainDouble2", 14.5);
+        map.props.put("doubleAsInt2", 200.0);
+
+        String json = gson.toJson(map);
+
+        map.props.clear();
+        map = gson.fromJson(json, MyObjectMap.class);
+
+        // everything should still be Double
+        assertEquals(14.5, map.props.get("plainDouble2"));
+        assertEquals(200.0, map.props.get("doubleAsInt2"));
+    }
+
+    private static class MyMap {
+        private Map<String, Object> props;
+    }
+
+    private static class MyDoubleMap {
+        private Map<String, Double> props;
+    }
+
+    private static class MyObjectMap {
+        private Map<Object, Object> props;
+    }
+
+}