[Java][Flexbuffers] Add API to add nullables into the buffer. (#7521)

Fix #7517
google · Sep 10, 2022 · b901598 · b901598
1 parent 8cdc6a2
commit b901598
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Showing 2 changed files with 29 additions and 5 deletions.
diff --git a/java/com/google/flatbuffers/FlexBuffersBuilder.java b/java/com/google/flatbuffers/FlexBuffersBuilder.java
@@ -173,6 +173,21 @@ public ReadWriteBuf getBuffer() {
         return bb;
     }
 
+    /**
+     * Insert a null value into the buffer
+     */
+    public void putNull() {
+        putNull(null);
+    }
+
+    /**
+     * Insert a null value into the buffer
+     * @param key key used to store element in map
+     */
+    public void putNull(String key) {
+        stack.add(Value.nullValue(putKey(key)));
+    }
+
     /**
      * Insert a single boolean into the buffer
      * @param val true or false
@@ -675,6 +690,10 @@ private static class Value {
             this.iValue = Long.MIN_VALUE;
         }
 
+        static Value nullValue(int key) {
+            return new Value(key, FBT_NULL, WIDTH_8, 0);
+        }
+
         static Value bool(int key, boolean b) {
             return new Value(key, FBT_BOOL, WIDTH_8, b ? 1 : 0);
         }

diff --git a/tests/JavaTest.java b/tests/JavaTest.java
@@ -959,21 +959,24 @@ public static void testSingleElementVector() {
         int vecPos = b.startVector();
         b.putInt(99);
         b.putString("wow");
+        b.putNull();
         int vecpos2 = b.startVector();
         b.putInt(99);
         b.putString("wow");
+        b.putNull();
         b.endVector(null, vecpos2, false, false);
         b.endVector(null, vecPos, false, false);
         b.finish();
 
         FlexBuffers.Reference r = FlexBuffers.getRoot(b.getBuffer());
         TestEq(FlexBuffers.FBT_VECTOR, r.getType());
         FlexBuffers.Vector vec = FlexBuffers.getRoot(b.getBuffer()).asVector();
-        TestEq(3, vec.size());
+        TestEq(4, vec.size());
         TestEq(99, vec.get(0).asInt());
         TestEq("wow", vec.get(1).asString());
-        TestEq("[ 99, \"wow\" ]", vec.get(2).toString());
-        TestEq("[ 99, \"wow\", [ 99, \"wow\" ] ]", FlexBuffers.getRoot(b.getBuffer()).toString());
+        TestEq(true, vec.get(2).isNull());
+        TestEq("[ 99, \"wow\", null ]", vec.get(3).toString());
+        TestEq("[ 99, \"wow\", null, [ 99, \"wow\", null ] ]", FlexBuffers.getRoot(b.getBuffer()).toString());
     }
 
     public static void testSingleElementMap() {
@@ -983,6 +986,7 @@ public static void testSingleElementMap() {
         b.putInt("myInt", 0x7fffffbbbfffffffL);
         b.putString("myString", "wow");
         b.putString("myString2", "incredible");
+        b.putNull("myNull");
         int start = b.startVector();
         b.putInt(99);
         b.putString("wow");
@@ -995,14 +999,15 @@ public static void testSingleElementMap() {
         FlexBuffers.Reference r = FlexBuffers.getRoot(b.getBuffer());
         TestEq(FlexBuffers.FBT_MAP, r.getType());
         FlexBuffers.Map map = FlexBuffers.getRoot(b.getBuffer()).asMap();
-        TestEq(5, map.size());
+        TestEq(6, map.size());
         TestEq(0x7fffffbbbfffffffL, map.get("myInt").asLong());
         TestEq("wow", map.get("myString").asString());
         TestEq("incredible", map.get("myString2").asString());
+        TestEq(true, map.get("myNull").isNull());
         TestEq(99, map.get("myVec").asVector().get(0).asInt());
         TestEq("wow", map.get("myVec").asVector().get(1).asString());
         TestEq(Double.compare(0x1.ffffbbbffffffP+1023, map.get("double").asFloat()), 0);
-        TestEq("{ \"double\" : 1.7976894783391937E308, \"myInt\" : 9223371743723257855, \"myString\" : \"wow\", \"myString2\" : \"incredible\", \"myVec\" : [ 99, \"wow\" ] }",
+        TestEq("{ \"double\" : 1.7976894783391937E308, \"myInt\" : 9223371743723257855, \"myNull\" : null, \"myString\" : \"wow\", \"myString2\" : \"incredible\", \"myVec\" : [ 99, \"wow\" ] }",
                 FlexBuffers.getRoot(b.getBuffer()).toString());
     }