Update LocalName AdStructure, remove trailing null characters from data

src/main/java/com/neovisionaries/bluetooth/ble/advertising/LocalName.java

@@ -18,6 +18,8 @@
 
 import java.io.UnsupportedEncodingException;
 
+import static com.neovisionaries.bluetooth.ble.util.Bytes.removeTrailingNulls;
+
 
 /**
  * An AD structure of type "Shortened Local Name" (type = 0x08)
@@ -71,14 +73,16 @@ public LocalName(int length, int type, byte[] data)
 
     private void parse(byte[] data)
     {
-        if (data == null || data.length < 1)
+        byte[] dataStr = removeTrailingNulls(data);
+
+        if (dataStr == null || dataStr.length < 1)
         {
             return;
         }
 
         try
         {
-            mLocalName = new String(data, "UTF-8");
+            mLocalName = new String(dataStr, "UTF-8");
         }
         catch (UnsupportedEncodingException e)
         {

src/main/java/com/neovisionaries/bluetooth/ble/util/Bytes.java

@@ -16,6 +16,7 @@
 package com.neovisionaries.bluetooth.ble.util;
 
 
+
 /**
  * Utility for byte arrays.
  *
@@ -164,4 +165,34 @@ public static byte[] copyOfRange(byte[] source, int from, int to)
 
         return destination;
     }
+
+    /**
+     * Remove trailing nulls from a byte array.
+     *
+     * @param data
+     *         An input byte array.
+
+     * @return
+     *         A byte array with any trailing null bytes removed.
+     */
+    public static byte[] removeTrailingNulls(byte[] data)
+    {
+        int length = lengthWithoutNulls(data);
+        byte[] result = new byte[length];
+
+        System.arraycopy(data, 0, result, 0, length);
+
+        return result;
+    }
+
+    private static int lengthWithoutNulls(byte[] data) {
+        if (data == null || data.length == 0)
+            return 0;
+
+        for (int i = 0; i < data.length; i++)
+            if (data[i] == '\0')
+                return i;
+
+        return data.length;
+    }
 }

src/test/java/com/neovisionaries/bluetooth/ble/StandardGattServiceTest.java

@@ -27,9 +27,17 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
+
+import java.util.List;
 import java.util.UUID;
+
+import com.neovisionaries.bluetooth.ble.advertising.ADPayloadParser;
+import com.neovisionaries.bluetooth.ble.advertising.ADStructure;
+import com.neovisionaries.bluetooth.ble.advertising.LocalName;
 import org.junit.Test;
 
+import javax.xml.bind.DatatypeConverter;
+
 
 public class StandardGattServiceTest
 {
@@ -51,6 +59,18 @@ private void uuidTest(String uuid, StandardGattService expected)
         compareInstances(expected, getByUuid(uuid));
     }
 
+    private String nameFromScanRecord(String hex)
+    {
+        byte[] scanRecord = DatatypeConverter.parseHexBinary(hex);
+        List<ADStructure> structures = ADPayloadParser.getInstance().parse(scanRecord);
+        for (ADStructure structure : structures) {
+            if (structure instanceof LocalName) {
+                LocalName name = (LocalName) structure;
+                return name.getLocalName();
+            }
+        }
+        return null;
+    }
 
     private void uuidTest(UUID uuid, StandardGattService expected)
     {
@@ -126,4 +146,12 @@ public void test10()
     {
         uuidTest(UUID.fromString("0000181F-0000-1000-8000-00805f9b34fb"), CONTINUOUS_GLUCOSE_MONITORING);
     }
+
+    @Test
+    public void test11()
+    {
+        // test extracting a name with a null terminated string
+        // "Name" = 4E616D65
+        assertEquals("Name", nameFromScanRecord("020102020A0C0319800006094E616D6500000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"));
+    }
 }