eclipse-leshan#682: Add SenML-CBOR encoder in leshan-core + unit tests.

Signed-off-by: Boya Zhang <zhangboya@gmail.com>

leshan-core/pom.xml

@@ -38,6 +38,10 @@ Contributors:
             <groupId>com.eclipsesource.minimal-json</groupId>
             <artifactId>minimal-json</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-cbor</artifactId>
+        </dependency>
 
         <!-- test dependencies -->
         <dependency>

leshan-core/src/main/java/org/eclipse/leshan/core/node/codec/senml/LwM2mNodeSenMLJsonEncoder.java

@@ -53,7 +53,7 @@ public static byte[] encode(LwM2mNode node, LwM2mPath path, LwM2mModel model, Lw
 
         SenMLPack pack = new SenMLPack();
         pack.setRecords(internalEncoder.records);
-        return SenMLJson.toJsonSenML(pack).getBytes();
+        return SenMLJson.toSenMLJson(pack).getBytes();
     }
 
     private static class InternalEncoder implements LwM2mNodeVisitor {

leshan-core/src/main/java/org/eclipse/leshan/senml/SenMLCbor.java

@@ -0,0 +1,26 @@
+/*******************************************************************************
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ * 
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.html.
+ * 
+ * Contributors:
+ *     Boya Zhang - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.leshan.senml;
+
+/**
+ * Helper for encoding/decoding SenML CBOR format
+ */
+public class SenMLCbor {
+    private static final SenMLCborPackSerDes serDes = new SenMLCborPackSerDes();
+
+    public static byte[] toSenMLCbor(SenMLPack pack) throws SenMLCborException {
+        return serDes.serializeToCbor(pack);
+    }
+}

leshan-core/src/main/java/org/eclipse/leshan/senml/SenMLCborException.java

@@ -0,0 +1,32 @@
+/*******************************************************************************
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ * 
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.html.
+ * 
+ * Contributors:
+ *     Boya Zhang - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.leshan.senml;
+
+/**
+ * Exception thrown in case of Cbor encoding error
+ */
+public class SenMLCborException extends Exception {
+
+    private static final long serialVersionUID = 1L;
+
+    public SenMLCborException(String message) {
+        super(message);
+    }
+
+    public SenMLCborException(String message, Exception cause) {
+        super(message, cause);
+    }
+
+}

leshan-core/src/main/java/org/eclipse/leshan/senml/SenMLCborPackSerDes.java

@@ -0,0 +1,119 @@
+/*******************************************************************************
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ * 
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.html.
+ * 
+ * Contributors:
+ *     Boya Zhang - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.leshan.senml;
+
+import java.io.ByteArrayOutputStream;
+
+import org.eclipse.leshan.core.model.ResourceModel.Type;
+
+import com.fasterxml.jackson.dataformat.cbor.CBORFactory;
+import com.fasterxml.jackson.dataformat.cbor.CBORGenerator;
+
+public class SenMLCborPackSerDes {
+
+    public byte[] serializeToCbor(SenMLPack pack) throws SenMLCborException {
+        CBORFactory factory = new CBORFactory();
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+        try {
+            CBORGenerator generator = factory.createGenerator(out);
+            generator.writeStartArray(pack.getRecords().size());
+
+            for (SenMLRecord record : pack.getRecords()) {
+                boolean hasBaseName = false;
+                boolean hasBaseTime = false;
+                boolean hasName = false;
+                boolean hasTime = false;
+                int objectSize = 1;
+
+                if (record.getBaseName() != null && !record.getBaseName().isEmpty()) {
+                    hasBaseName = true;
+                    objectSize++;
+                }
+
+                if (record.getBaseTime() != null) {
+                    hasBaseTime = true;
+                    objectSize++;
+                }
+
+                if (record.getName() != null && !record.getName().isEmpty()) {
+                    hasName = true;
+                    objectSize++;
+                }
+
+                if (record.getTime() != null) {
+                    hasTime = true;
+                    objectSize++;
+                }
+
+                generator.writeStartObject(objectSize);
+
+                if (hasBaseName) {
+                    generator.writeFieldId(-2);
+                    generator.writeString(record.getBaseName());
+                }
+
+                if (hasBaseTime) {
+                    generator.writeFieldId(-3);
+                    generator.writeNumber(record.getBaseTime());
+                }
+
+                if (hasName) {
+                    generator.writeFieldId(0);
+                    generator.writeString(record.getName());
+                }
+
+                if (hasTime) {
+                    generator.writeFieldId(6);
+                    generator.writeNumber(record.getTime());
+                }
+
+                Type type = record.getType();
+                if (type != null) {
+                    switch (record.getType()) {
+                    case FLOAT:
+                        generator.writeFieldId(2);
+                        generator.writeNumber(record.getFloatValue().intValue());
+                        break;
+                    case BOOLEAN:
+                        generator.writeFieldId(4);
+                        generator.writeBoolean(record.getBooleanValue());
+                        break;
+                    case OBJLNK:
+                        generator.writeStringField("vlo", record.getObjectLinkValue());
+                        break;
+                    case OPAQUE:
+                        generator.writeFieldId(8);
+                        generator.writeBinary(record.getOpaqueValue());
+                    case STRING:
+                        generator.writeFieldId(3);
+                        generator.writeString(record.getStringValue());
+                        break;
+                    default:
+                        break;
+                    }
+                }
+                generator.writeEndObject();
+            }
+
+            generator.writeEndArray();
+            generator.close();
+        } catch (Exception ex) {
+            throw new SenMLCborException("Impossible to encode pack to CBOR: \n" + pack, ex);
+        }
+
+        return out.toByteArray();
+    }
+}

leshan-core/src/main/java/org/eclipse/leshan/senml/SenMLJson.java

@@ -20,13 +20,13 @@
  * Helper for encoding/decoding SenML JSON format
  */
 public class SenMLJson {
-    private static final SenMLPackSerDes serDes = new SenMLPackSerDes();
+    private static final SenMLJsonPackSerDes serDes = new SenMLJsonPackSerDes();
 
-    public static String toJsonSenML(SenMLPack pack) {
-        return serDes.serialize(pack);
+    public static String toSenMLJson(SenMLPack pack) {
+        return serDes.serializeToJson(pack);
     }
 
-    public static SenMLPack fromJsonSenML(String jsonString) {
-        return serDes.deserialize(Json.parse(jsonString).asArray());
+    public static SenMLPack fromSenMLJson(String jsonString) {
+        return serDes.deserializeFromJson(Json.parse(jsonString).asArray());
     }
 }

leshan-core/src/main/java/org/eclipse/leshan/senml/SenMLPackSerDes.java → leshan-core/src/main/java/org/eclipse/leshan/senml/SenMLJsonPackSerDes.java

@@ -21,9 +21,9 @@
 import com.eclipsesource.json.JsonObject;
 import com.eclipsesource.json.JsonValue;
 
-public class SenMLPackSerDes {
+public class SenMLJsonPackSerDes {
 
-    public String serialize(SenMLPack pack) {
+    public String serializeToJson(SenMLPack pack) {
         JsonArray jsonArray = new JsonArray();
 
         for (SenMLRecord record : pack.getRecords()) {
@@ -73,7 +73,7 @@ public String serialize(SenMLPack pack) {
         return jsonArray.toString();
     }
 
-    public SenMLPack deserialize(JsonArray array) {
+    public SenMLPack deserializeFromJson(JsonArray array) {
 
         if (array == null)
             return null;

leshan-core/src/test/java/org/eclipse/leshan/senml/AbstractSenMLTest.java

@@ -0,0 +1,88 @@
+/*******************************************************************************
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ * 
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.html.
+ * 
+ * Contributors:
+ *     Boya Zhang - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.leshan.senml;
+
+public abstract class AbstractSenMLTest {
+    protected void givenResourceWithFloatValue(SenMLPack pack, String n, Number value) {
+        SenMLRecord elt = new SenMLRecord();
+        elt.setName(n);
+        elt.setFloatValue(value);
+        pack.addRecord(elt);
+    }
+
+    protected void givenResourceWithStringValue(SenMLPack pack, String n, String value) {
+        givenResourceWithStringValue(pack, null, n, value);
+    }
+
+    protected void givenResourceWithStringValue(SenMLPack pack, String bn, String n, String value) {
+        SenMLRecord elt = new SenMLRecord();
+        if (bn != null) {
+            elt.setBaseName(bn);
+        }
+
+        elt.setName(n);
+        elt.setStringValue(value);
+        pack.addRecord(elt);
+    }
+
+    /**
+     * Example of JSON payload request to Device Object of the LwM2M example client (Read /3/0)
+     * 
+     * @return JSON payload
+     */
+    protected String givenSenMLJsonExample() {
+        StringBuilder b = new StringBuilder();
+        b.append("[{\"bn\":\"/3/0/\",\"n\":\"0\",\"vs\":\"Open Mobile Alliance\"},");
+        b.append("{\"n\":\"1\",\"vs\":\"Lightweight M2M Client\"},");
+        b.append("{\"n\":\"2\",\"vs\":\"345000123\"},");
+        b.append("{\"n\":\"3\",\"vs\":\"1.0\"},");
+        b.append("{\"n\":\"6/0\",\"v\":1},{\"n\":\"6/1\",\"v\":5},");
+        b.append("{\"n\":\"7/0\",\"v\":3800},{\"n\":\"7/1\",\"v\":5000},");
+        b.append("{\"n\":\"8/0\",\"v\":125},{\"n\":\"8/1\",\"v\":900},");
+        b.append("{\"n\":\"9\",\"v\":100},");
+        b.append("{\"n\":\"10\",\"v\":15},");
+        b.append("{\"n\":\"11/0\",\"v\":0},");
+        b.append("{\"n\":\"13\",\"v\":1.3674912E9},");
+        b.append("{\"n\":\"14\",\"vs\":\"+02:00\"},");
+        b.append("{\"n\":\"16\",\"vs\":\"U\"}]");
+        return b.toString();
+    }
+
+    protected SenMLPack givenDeviceObjectInstance() {
+        SenMLPack pack = new SenMLPack();
+
+        givenResourceWithStringValue(pack, "/3/0/", "0", "Open Mobile Alliance");
+        givenResourceWithStringValue(pack, "1", "Lightweight M2M Client");
+        givenResourceWithStringValue(pack, "2", "345000123");
+        givenResourceWithStringValue(pack, "3", "1.0");
+
+        givenResourceWithFloatValue(pack, "6/0", 1);
+        givenResourceWithFloatValue(pack, "6/1", 5);
+        givenResourceWithFloatValue(pack, "7/0", 3800);
+        givenResourceWithFloatValue(pack, "7/1", 5000);
+        givenResourceWithFloatValue(pack, "8/0", 125);
+        givenResourceWithFloatValue(pack, "8/1", 900);
+
+        givenResourceWithFloatValue(pack, "9", 100);
+        givenResourceWithFloatValue(pack, "10", 15);
+        givenResourceWithFloatValue(pack, "11/0", 0);
+        givenResourceWithFloatValue(pack, "13", 1367491215l);
+
+        givenResourceWithStringValue(pack, "14", "+02:00");
+        givenResourceWithStringValue(pack, "16", "U");
+
+        return pack;
+    }
+}

leshan-core/src/test/java/org/eclipse/leshan/senml/SenMLCborSerializerTest.java

@@ -0,0 +1,34 @@
+/*******************************************************************************
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Eclipse Distribution License v1.0 which accompany this distribution.
+ * 
+ * The Eclipse Public License is available at
+ *    http://www.eclipse.org/legal/epl-v10.html
+ * and the Eclipse Distribution License is available at
+ *    http://www.eclipse.org/org/documents/edl-v10.html.
+ * 
+ * Contributors:
+ *     Boya Zhang - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.leshan.senml;
+
+import org.eclipse.leshan.util.Hex;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class SenMLCborSerializerTest extends AbstractSenMLTest {
+
+    @Test
+    public void serialize_device_object_to_senml_cbor() throws Exception {
+        byte[] cbor = SenMLCbor.toSenMLCbor(givenDeviceObjectInstance());
+
+        String expectedValue = "90a321652f332f302f00613003744f70656e204d6f62696c6520416c6c69616e6365a200613103764c696768747765696768"
+                + "74204d324d20436c69656e74a20061320369333435303030313233a20061330363312e30a20063362f300201a20063362f310205a20063372f"
+                + "3002190ed8a20063372f3102191388a20063382f3002187da20063382f3102190384a2006139021864a200623130020fa2006431312f300200"
+                + "a200623133021a5182428fa20062313403662b30323a3030a200623136036155";
+
+        Assert.assertTrue(expectedValue.equals(Hex.encodeHexString(cbor)));
+    }
+}