Add support for nullable numbers with default values (mimics HLRC)

Author: swallez

java-client/src/main/java/co/elastic/clients/json/JsonpDeserializer.java

@@ -181,6 +181,16 @@ static JsonpDeserializer<Double> doubleDeserializer() {
         return JsonpDeserializerBase.DOUBLE;
     }
 
+    /** A {@code double} deserializer that will return a default value when the JSON value is {@code null} */
+    static JsonpDeserializer<Double> doubleOrNullDeserializer(double defaultValue) {
+        return new JsonpDeserializerBase.DoubleOrNullDeserializer(defaultValue);
+    }
+
+    /** An {@code integer} deserializer that will return a default value when the JSON value is {@code null} */
+    static JsonpDeserializer<Integer> intOrNullDeserializer(int defaultValue) {
+        return new JsonpDeserializerBase.IntOrNullDeserializer(defaultValue);
+    }
+
     static JsonpDeserializer<Number> numberDeserializer() {
         return JsonpDeserializerBase.NUMBER;
     }

java-client/src/main/java/co/elastic/clients/json/JsonpDeserializerBase.java

@@ -181,6 +181,67 @@ public Double deserialize(JsonParser parser, JsonpMapper mapper, Event event) {
             }
         };
 
+    static final class DoubleOrNullDeserializer extends JsonpDeserializerBase<Double> {
+        static final EnumSet<Event> nativeEvents = EnumSet.of(Event.VALUE_NUMBER, Event.VALUE_NULL);
+        static final EnumSet<Event> acceptedEvents = EnumSet.of(Event.VALUE_STRING, Event.VALUE_NUMBER, Event.VALUE_NULL);
+        private final double defaultValue;
+
+        DoubleOrNullDeserializer(double defaultValue) {
+            super(acceptedEvents, nativeEvents);
+            this.defaultValue = defaultValue;
+        }
+
+        @Override
+        public Double deserialize(JsonParser parser, JsonpMapper mapper, Event event) {
+            if (event == Event.VALUE_NULL) {
+                return defaultValue;
+            }
+            if (event == Event.VALUE_STRING) {
+                return Double.valueOf(parser.getString());
+            }
+            return parser.getBigDecimal().doubleValue();
+        }
+    }
+
+    static final class IntOrNullDeserializer extends JsonpDeserializerBase<Integer> {
+        static final EnumSet<Event> nativeEvents = EnumSet.of(Event.VALUE_NUMBER, Event.VALUE_NULL);
+        static final EnumSet<Event> acceptedEvents = EnumSet.of(Event.VALUE_STRING, Event.VALUE_NUMBER, Event.VALUE_NULL);
+        private final int defaultValue;
+
+        IntOrNullDeserializer(int defaultValue) {
+            super(acceptedEvents, nativeEvents);
+            this.defaultValue = defaultValue;
+        }
+
+        @Override
+        public Integer deserialize(JsonParser parser, JsonpMapper mapper, Event event) {
+            if (event == Event.VALUE_NULL) {
+                return defaultValue;
+            }
+            if (event == Event.VALUE_STRING) {
+                return Integer.valueOf(parser.getString());
+            }
+            return parser.getInt();
+        }
+    }
+
+    static final JsonpDeserializer<Double> DOUBLE_OR_NAN =
+        new JsonpDeserializerBase<Double>(
+            EnumSet.of(Event.VALUE_NUMBER, Event.VALUE_STRING, Event.VALUE_NULL),
+            EnumSet.of(Event.VALUE_NUMBER, Event.VALUE_NULL)
+        ) {
+            @Override
+            public Double deserialize(JsonParser parser, JsonpMapper mapper, Event event) {
+                if (event == Event.VALUE_NULL) {
+                    return Double.NaN;
+                }
+                if (event == Event.VALUE_STRING) {
+                    return Double.valueOf(parser.getString());
+                }
+                return parser.getBigDecimal().doubleValue();
+            }
+        };
+
     static final JsonpDeserializer<Number> NUMBER =
         new JsonpDeserializerBase<Number>(
             EnumSet.of(Event.VALUE_NUMBER, Event.VALUE_STRING),

java-client/src/main/java/co/elastic/clients/json/JsonpUtils.java

@@ -180,4 +180,22 @@ public static String toString(JsonValue value) {
                 throw new IllegalArgumentException("Unknown JSON value type: '" + value + "'");
         }
     }
+
+    public static void serializeDoubleOrNull(JsonGenerator generator, double value, double defaultValue) {
+        // Only output null if the default value isn't finite, which cannot be represented as JSON
+        if (value == defaultValue && !Double.isFinite(defaultValue)) {
+            generator.writeNull();
+        } else {
+            generator.write(value);
+        }
+    }
+
+    public static void serializeIntOrNull(JsonGenerator generator, int value, int defaultValue) {
+        // Only output null if the default value isn't finite, which cannot be represented as JSON
+        if (value == defaultValue && defaultValue == Integer.MAX_VALUE || defaultValue == Integer.MIN_VALUE) {
+            generator.writeNull();
+        } else {
+            generator.write(value);
+        }
+    }
 }

java-client/src/main/java/co/elastic/clients/util/ApiTypeHelper.java

@@ -116,7 +116,7 @@ public static <T> List<T> undefinedList() {
      * <p>
      * List setters on API type builders add items to the property using {@link List#addAll(Collection)} and do not accept
      * a {@code null} value which is considered as a bug. In some rare occasions it may however be necessary to reset
-     * the builder's property, and this what the result of this method is meant for: setting a builder's list property
+     * the builder's property, and this is what the result of this method is meant for: setting a builder's list property
      * to the value returned by this method will reset that property to {@code null}.
      */
     @SuppressWarnings("unchecked")
@@ -183,7 +183,7 @@ public static <K, V> Map<K, V> undefinedMap() {
      * <p>
      * Map setters on API type builders add entries to the property using {@link Map#putAll(Map)} and do not accept
      * a {@code null} value which is considered as a bug. In some rare occasions it may however be necessary to reset
-     * the builder's property, and this what the result of this method is meant for: setting a builder's map property
+     * the builder's property, and this is what the result of this method is meant for: setting a builder's map property
      * to the value returned by this method will reset that property to {@code null}.
      */
     @SuppressWarnings("unchecked")

java-client/src/test/java/co/elastic/clients/elasticsearch/end_to_end/RequestTest.java

@@ -168,6 +168,16 @@ public void testDataIngestion() throws Exception {
         assertEquals(1337, esData.getIntValue());
         assertEquals("foo", esData.getMsg());
 
+        // Query by id a non-existing document
+        final GetResponse<AppData> notExists = client.get(b -> b
+                .index(index)
+                .id("some-random-id")
+            , AppData.class
+        );
+
+        assertFalse(notExists.found());
+        assertNull(notExists.source());
+
         // Search
         SearchResponse<AppData> search = client.search(b -> b
                 .index(index)

java-client/src/test/java/co/elastic/clients/elasticsearch/model/BuiltinTypesTest.java

@@ -22,6 +22,8 @@
 import co.elastic.clients.elasticsearch._types.FieldValue;
 import co.elastic.clients.elasticsearch._types.SortOptions;
 import co.elastic.clients.elasticsearch._types.SortOrder;
+import co.elastic.clients.elasticsearch._types.aggregations.StatsAggregate;
+import co.elastic.clients.elasticsearch._types.aggregations.StringStatsAggregate;
 import co.elastic.clients.elasticsearch._types.query_dsl.SpanGapQuery;
 import co.elastic.clients.elasticsearch.core.SearchRequest;
 import co.elastic.clients.elasticsearch.indices.IndexSettings;
@@ -159,4 +161,60 @@ public void testFieldValue() {
         assertEquals("foo", f._toJsonString());
 
     }
+
+    @Test
+    public void testNullableDouble() {
+        StatsAggregate stats;
+
+        // Regular values
+        stats = StatsAggregate.statsAggregateOf(b -> b // Parent classes can't have an overloaded "of" method
+            .count(10)
+            .min(1.0)
+            .avg(1.5)
+            .max(2.0)
+            .sum(5.0)
+        );
+
+        stats = checkJsonRoundtrip(stats, "{\"count\":10,\"min\":1.0,\"max\":2.0,\"avg\":1.5,\"sum\":5.0}");
+        assertEquals(10, stats.count());
+        assertEquals(1.0, stats.min(), 0.01);
+        assertEquals(1.5, stats.avg(), 0.01);
+        assertEquals(2.0, stats.max(), 0.01);
+        assertEquals(5.0, stats.sum(), 0.01);
+
+        // Missing values (JSON null, Java infinite)
+        String json = "{\"count\":0,\"min\":null,\"max\":null,\"avg\":null,\"sum\":0.0}";
+        stats = fromJson(json, StatsAggregate.class);
+
+        assertEquals(0, stats.count());
+        assertTrue(Double.isInfinite(stats.min()));
+        assertEquals(0.0, stats.avg(), 0.01);
+        assertTrue(Double.isInfinite(stats.max()));
+        assertEquals(0.0, stats.sum(), 0.01);
+
+        // We don't serialize finite default values as null
+        assertEquals("{\"count\":0,\"min\":null,\"max\":null,\"avg\":0.0,\"sum\":0.0}", toJson(stats));
+    }
+
+    @Test
+    public void testNullableInt() {
+        StringStatsAggregate stats = StringStatsAggregate.of(b -> b
+            .count(1)
+            .minLength(2)
+            .avgLength(3)
+            .maxLength(4)
+            .entropy(0)
+        );
+
+        stats = checkJsonRoundtrip(stats, "{\"count\":1,\"min_length\":2,\"max_length\":4,\"avg_length\":3.0,\"entropy\":0.0}");
+        assertEquals(2, stats.minLength());
+        assertEquals(4, stats.maxLength());
+
+        // Missing values
+        String json = "{\"count\":1,\"min_length\":null,\"max_length\":null,\"avg_length\":null,\"entropy\":null}";
+        stats = fromJson(json, StringStatsAggregate.class);
+        assertEquals(0, stats.minLength());
+        assertEquals(0, stats.maxLength());
+        assertEquals(0.0, stats.entropy(), 0.01);
+    }
 }