1 files changed, 117 insertions, 0 deletions
diff --git a/gson/src/main/java/org/onap/policy/common/gson/DoubleConverter.java b/gson/src/main/java/org/onap/policy/common/gson/DoubleConverter.java
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+/*
+ * ============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 java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+
+/**
+ * Converter for Double values. By default, GSON treats all Objects that are numbers, as
+ * Double. This converts Doubles to Integer or Long, if possible. It converts stand-alone
+ * Doubles, as well as those found within Arrays and Maps.
+ */
+public class DoubleConverter {
+
+    private DoubleConverter() {
+        // do nothing
+    }
+
+    /**
+     * Performs in-place conversion of all values in a list.
+     *
+     * @param list the list whose values are to be converted
+     */
+    public static void convertFromDouble(List<Object> list) {
+        if (list == null) {
+            return;
+        }
+
+        List<Object> original = new ArrayList<>(list);
+
+        list.clear();
+        original.forEach(item -> list.add(convertFromDouble(item)));
+    }
+
+    /**
+     * Performs in-place conversion of all values in a map.
+     *
+     * @param map the map whose values are to be converted
+     */
+    public static void convertFromDouble(Map<String, Object> map) {
+        if (map == null) {
+            return;
+        }
+
+        Set<Entry<String, Object>> set = map.entrySet();
+
+        for (Entry<String, Object> entry : set) {
+            entry.setValue(convertFromDouble(entry.getValue()));
+        }
+    }
+
+    /**
+     * Converts a value. If the value is a List, then it recursively converts the
+     * entries of the List. Likewise with a map, however, the map is converted in place.
+     *
+     * @param value value to be converted
+     * @return the converted value
+     */
+    @SuppressWarnings({"unchecked"})
+    public static Object convertFromDouble(Object value) {
+        if (value == null) {
+            return value;
+        }
+
+        if (value instanceof List) {
+            convertFromDouble((List<Object>) value);
+            return value;
+        }
+
+        if (value instanceof Map) {
+            convertFromDouble((Map<String, Object>) value);
+            return value;
+        }
+
+        if (!(value instanceof Double)) {
+            return value;
+        }
+
+        Double num = (Double) value;
+        long longval = num.longValue();
+
+        if (Double.compare(num.doubleValue(), longval) != 0) {
+            // it isn't integral - return unchanged value
+            return value;
+        }
+
+        // it's integral - determine if it's an integer or a long
+        int intval = (int) longval;
+
+        if (intval == longval) {
+            return intval;
+        }
+
+        return longval;
+    }
+}