Fix sonar issues in gson superclasses

Fixing some of the issues necessitated the use of generic/raw types.
Removed version from assertj in pom.
Removed trailing spaces.

Change-Id: I76e0a05ca06c103ccc876675be04a4ab5e4de5ea
Issue-ID: POLICY-1428
Signed-off-by: Jim Hahn <jrh3@att.com>
diff --git a/gson/pom.xml b/gson/pom.xml
index 3b9983f..110fccb 100644
--- a/gson/pom.xml
+++ b/gson/pom.xml
@@ -55,7 +55,6 @@
         <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
-            <version>3.11.1</version>
             <scope>test</scope>
         </dependency>
         <dependency>
diff --git a/gson/src/main/java/org/onap/policy/common/gson/GsonMessageBodyHandler.java b/gson/src/main/java/org/onap/policy/common/gson/GsonMessageBodyHandler.java
index 2112c97..66475e3 100644
--- a/gson/src/main/java/org/onap/policy/common/gson/GsonMessageBodyHandler.java
+++ b/gson/src/main/java/org/onap/policy/common/gson/GsonMessageBodyHandler.java
@@ -80,7 +80,7 @@
     @Override
     public void writeTo(Object object, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType,
                     MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
-                    throws IOException, WebApplicationException {
+                    throws IOException {
 
         try (OutputStreamWriter writer = new OutputStreamWriter(entityStream, StandardCharsets.UTF_8)) {
             Type jsonType = (type.equals(genericType) ? type : genericType);
@@ -107,8 +107,11 @@
 
         String subtype = mediaType.getSubtype();
 
-        return "json".equalsIgnoreCase(subtype) || subtype.endsWith("+json") || "javascript".equals(subtype)
-                        || "x-javascript".equals(subtype) || "x-json".equals(subtype);
+        if ("json".equalsIgnoreCase(subtype) || "javascript".equals(subtype)) {
+            return true;
+        }
+
+        return subtype.endsWith("+json") || "x-json".equals(subtype) || "x-javascript".equals(subtype);
     }
 
     @Override
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/Adapter.java b/gson/src/main/java/org/onap/policy/common/gson/internal/Adapter.java
index b4ef53f..94091c7 100644
--- a/gson/src/main/java/org/onap/policy/common/gson/internal/Adapter.java
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/Adapter.java
@@ -116,8 +116,9 @@
         }
 
         ConvInfo wtr = writer;
-        TypeAdapter<Object> conv =
-                        (TypeAdapter<Object>) (wtr.clazz == clazz ? wtr.getConverter() : gson.getAdapter(clazz));
+
+        @SuppressWarnings("rawtypes")
+        TypeAdapter conv = (wtr.clazz == clazz ? wtr.getConverter() : gson.getAdapter(clazz));
 
         return conv.toJsonTree(object);
     }
@@ -305,29 +306,33 @@
         /**
          * Type on which the converter works.
          */
-        private TypeToken<?> type;
+        @SuppressWarnings("rawtypes")
+        private TypeToken type;
 
         /**
          * Class of object on which the converter works.
          */
-        private Class<?> clazz;
+        @SuppressWarnings("rawtypes")
+        private Class clazz;
 
         /**
          * Converter to use, initialized lazily.
          */
-        private volatile TypeAdapter<?> conv = null;
+        @SuppressWarnings("rawtypes")
+        private volatile TypeAdapter conv = null;
 
         /**
          * Constructs the object.
          *
          * @param type type of object to be converted
          */
-        public ConvInfo(TypeToken<?> type) {
+        public ConvInfo(@SuppressWarnings("rawtypes") TypeToken type) {
             this.type = type;
             this.clazz = type.getRawType();
         }
 
-        public final TypeAdapter<?> getConverter() {
+        @SuppressWarnings({"rawtypes", "unchecked"})
+        public final TypeAdapter getConverter() {
             if (conv == null) {
                 // race condition here, but it's ok to overwrite a previous value
                 this.conv = gson.getAdapter(type);
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/ClassWalker.java b/gson/src/main/java/org/onap/policy/common/gson/internal/ClassWalker.java
index e985d98..89e4f89 100644
--- a/gson/src/main/java/org/onap/policy/common/gson/internal/ClassWalker.java
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/ClassWalker.java
@@ -122,7 +122,7 @@
      * @return the property names having a non-null value
      */
     private List<String> getNonNull(Map<String, Object> props) {
-        List<String> lst = new ArrayList<String>(props.size());
+        List<String> lst = new ArrayList<>(props.size());
 
         for (Entry<String, Object> ent : props.entrySet()) {
             if (ent.getValue() != null) {
@@ -162,7 +162,7 @@
      */
     @SuppressWarnings("unchecked")
     private <T> List<T> getProps(Class<T> clazz, Collection<Object> values) {
-        List<T> lst = new ArrayList<T>(values.size());
+        List<T> lst = new ArrayList<>(values.size());
 
         for (Object val : values) {
             if (val != null && val.getClass() == clazz) {
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/Deserializer.java b/gson/src/main/java/org/onap/policy/common/gson/internal/Deserializer.java
index f297586..4bf6e0c 100644
--- a/gson/src/main/java/org/onap/policy/common/gson/internal/Deserializer.java
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/Deserializer.java
@@ -25,10 +25,9 @@
 /**
  * Super class of all de-serializers.
  */
+@FunctionalInterface
 public interface Deserializer {
 
-    String INVOKE_ERR = "cannot invoke method to deserialize: ";
-
     /**
      * Gets an value from a tree, converts it, and puts it into a target object.
      *
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/Serializer.java b/gson/src/main/java/org/onap/policy/common/gson/internal/Serializer.java
index 2e2782a..254a5fe 100644
--- a/gson/src/main/java/org/onap/policy/common/gson/internal/Serializer.java
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/Serializer.java
@@ -25,6 +25,7 @@
 /**
  * Super class of all serializers.
  */
+@FunctionalInterface
 public interface Serializer {
 
     /**