#915: Add support of empty multi instance resource to SenML format

eclipse-leshan · Oct 19, 2021 · b6528f3 · b6528f3
1 parent 64c0ba6
commit b6528f3
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Showing 4 changed files with 88 additions and 10 deletions.
diff --git a/...an-core/src/main/java/org/eclipse/leshan/core/node/codec/senml/LwM2mNodeSenMLDecoder.java b/...an-core/src/main/java/org/eclipse/leshan/core/node/codec/senml/LwM2mNodeSenMLDecoder.java
@@ -214,15 +214,27 @@ private LwM2mNode parseRecords(Collection<LwM2mResolvedSenMLRecord> records, LwM
             if (recordsByInstanceId.size() > 1)
                 throw new CodecException("Only one instance expected in the payload [path:%s]", path);
 
-            // Extract resources
-            Map<Integer, LwM2mResource> resourcesMap = extractLwM2mResources(
-                    recordsByInstanceId.values().iterator().next(), path, model);
+            // handle empty multi instance resource ?
+            if (recordsByInstanceId.size() == 0) {
+                ResourceModel resourceModel = model.getResourceModel(path.getObjectId(), path.getResourceId());
+                if (resourceModel == null || !resourceModel.multiple) {
+                    throw new CodecException(
+                            "One resource should be present in the payload [path:%s] for single instance resource",
+                            path);
+                }
 
-            // validate there is only 1 resource
-            if (resourcesMap.size() != 1)
-                throw new CodecException("One resource should be present in the payload [path:%s]", path);
+                node = new LwM2mMultipleResource(path.getResourceId(), resourceModel.type);
+            } else {
+                // Extract resources
+                Map<Integer, LwM2mResource> resourcesMap = extractLwM2mResources(
+                        recordsByInstanceId.values().iterator().next(), path, model);
 
-            node = resourcesMap.values().iterator().next();
+                // validate there is only 1 resource
+                if (resourcesMap.size() != 1)
+                    throw new CodecException("One resource should be present in the payload [path:%s]", path);
+
+                node = resourcesMap.values().iterator().next();
+            }
         } else if (nodeClass == LwM2mResourceInstance.class) {
             // validate we have resources for only 1 instance
             if (recordsByInstanceId.size() > 1)

diff --git a/...in/java/org/eclipse/leshan/senml/cbor/upokecenter/SenMLCborUpokecenterEncoderDecoder.java b/...in/java/org/eclipse/leshan/senml/cbor/upokecenter/SenMLCborUpokecenterEncoderDecoder.java
@@ -71,6 +71,11 @@ public byte[] toSenML(SenMLPack pack) throws SenMLException {
     @Override
     public SenMLPack fromSenML(byte[] data) throws SenMLException {
         try {
+            // handle empty payload
+            if (data.length == 0) {
+                return new SenMLPack();
+            }
+
             CBORObject cborObject = CBORObject.DecodeFromBytes(data);
             if (cborObject.getType() != CBORType.Array) {
                 throw new SenMLException("Unable to parse SenML CBOR: Array expected but was %s", cborObject.getType());

diff --git a/...e/src/main/java/org/eclipse/leshan/senml/json/jackson/SenMLJsonJacksonEncoderDecoder.java b/...e/src/main/java/org/eclipse/leshan/senml/json/jackson/SenMLJsonJacksonEncoderDecoder.java
@@ -64,12 +64,18 @@ public byte[] toSenML(SenMLPack pack) throws SenMLException {
     @Override
     public SenMLPack fromSenML(byte[] jsonString) throws SenMLException {
         try {
+            // handle empty payload
+            if (jsonString == null || jsonString.length == 0) {
+                return new SenMLPack();
+            }
+
             JsonNode node = mapper.readTree(jsonString);
             if (!node.isArray()) {
                 throw new SenMLException("Unable to parse SenML JSON: JsonArray expected but was %s",
                         node.getNodeType());
             }
             return new SenMLPack(serDes.deserialize(node.iterator()));
+
         } catch (JsonException | ParseException | IOException e) {
             throw new SenMLException("Unable to parse SenML JSON.", e);
         }

diff --git a/leshan-core/src/test/java/org/eclipse/leshan/core/node/codec/LwM2mNodeDecoderTest.java b/leshan-core/src/test/java/org/eclipse/leshan/core/node/codec/LwM2mNodeDecoderTest.java
@@ -369,7 +369,7 @@ public void tlv_instance_without_id_tlv() throws CodecException {
         // this is "special" case where instance ID is not defined ...
         byte[] content = TlvEncoder
                 .encode(new Tlv[] { new Tlv(TlvType.RESOURCE_VALUE, null, TlvEncoder.encodeInteger(11), 1),
-                                        new Tlv(TlvType.RESOURCE_VALUE, null, TlvEncoder.encodeInteger(10), 2) })
+                        new Tlv(TlvType.RESOURCE_VALUE, null, TlvEncoder.encodeInteger(10), 2) })
                 .array();
 
         LwM2mObject object = (LwM2mObject) decoder.decode(content, ContentFormat.TLV, new LwM2mPath(2), model);
@@ -381,8 +381,7 @@ public void tlv_instance_without_id_tlv() throws CodecException {
     public void tlv_unknown_object__missing_instance_tlv() throws CodecException {
 
         byte[] content = TlvEncoder.encode(new Tlv[] { new Tlv(TlvType.RESOURCE_VALUE, null, "value1".getBytes(), 1),
-                                new Tlv(TlvType.RESOURCE_VALUE, null, "value1".getBytes(), 2) })
-                .array();
+                new Tlv(TlvType.RESOURCE_VALUE, null, "value1".getBytes(), 2) }).array();
 
         LwM2mObject obj = (LwM2mObject) decoder.decode(content, ContentFormat.TLV, new LwM2mPath(10234), model);
 
@@ -950,6 +949,40 @@ public void senml_json_decode_long() {
         assertEquals(9223372036854775800l, resource.getValue());
     }
 
+    @Test
+    public void senml_json_empty_multi_resource() {
+        // see : https://github.com/OpenMobileAlliance/OMA_LwM2M_for_Developers/issues/494
+
+        // empty byte array
+        LwM2mResource resource = null;
+        resource = (LwM2mResource) decoder.decode(new byte[0], ContentFormat.SENML_JSON, new LwM2mPath(3, 0, 6), model);
+        assertNotNull(resource);
+        assertTrue(resource instanceof LwM2mMultipleResource);
+        assertEquals(6, resource.getId());
+        assertTrue(resource.getInstances().isEmpty());
+
+        // empty string
+        resource = null;
+        StringBuilder b = new StringBuilder();
+        b.append("");
+        resource = (LwM2mResource) decoder.decode(b.toString().getBytes(), ContentFormat.SENML_JSON,
+                new LwM2mPath(3, 0, 6), model);
+        assertNotNull(resource);
+        assertTrue(resource instanceof LwM2mMultipleResource);
+        assertEquals(6, resource.getId());
+        assertTrue(resource.getInstances().isEmpty());
+
+        // empty Array
+        b = new StringBuilder();
+        b.append("[]");
+        resource = (LwM2mResource) decoder.decode(b.toString().getBytes(), ContentFormat.SENML_JSON,
+                new LwM2mPath(3, 0, 6), model);
+        assertNotNull(resource);
+        assertTrue(resource instanceof LwM2mMultipleResource);
+        assertEquals(6, resource.getId());
+        assertTrue(resource.getInstances().isEmpty());
+    }
+
     @Test
     public void senml_timestamped_resources() throws CodecException {
         // json content for instance 0 of device object
@@ -1192,4 +1225,26 @@ public void senml_cbor_decode_opaque_resource() {
 
         Assert.assertEquals(expected, oResource);
     }
+
+    @Test
+    public void senml_cbor_empty_multi_resource() {
+        // see : https://github.com/OpenMobileAlliance/OMA_LwM2M_for_Developers/issues/494
+
+        // empty byte array
+        LwM2mResource resource = null;
+        resource = (LwM2mResource) decoder.decode(new byte[0], ContentFormat.SENML_CBOR, new LwM2mPath(3, 0, 6), model);
+        assertNotNull(resource);
+        assertTrue(resource instanceof LwM2mMultipleResource);
+        assertEquals(6, resource.getId());
+        assertTrue(resource.getInstances().isEmpty());
+
+        // empty Array
+        // value : []
+        byte[] cbor = Hex.decodeHex("80".toCharArray());
+        resource = (LwM2mResource) decoder.decode(cbor, ContentFormat.SENML_CBOR, new LwM2mPath(3, 0, 6), model);
+        assertNotNull(resource);
+        assertTrue(resource instanceof LwM2mMultipleResource);
+        assertEquals(6, resource.getId());
+        assertTrue(resource.getInstances().isEmpty());
+    }
 }