Add lint unchecked and deprecated warnings to compiler config (#94)

Signed-off-by: Pavol Loffay <[email protected]>

Author: pavolloffay

build.gradle.kts

@@ -11,6 +11,11 @@ allprojects {
         sourceCompatibility = JavaVersion.VERSION_1_8
         targetCompatibility = JavaVersion.VERSION_1_8
     }
+
+    tasks.withType<JavaCompile> {
+        options.compilerArgs.add("-Xlint:unchecked")
+        options.isDeprecation = true
+    }
 }
 
 val testDependencies by configurations.creating {

instrumentation/grpc-1.5/src/main/java/io/opentelemetry/instrumentation/hypertrace/grpc/v1_5/GrpcSpanDecorator.java

@@ -71,7 +71,7 @@ public static void addMetadataAttributes(
   }
 
   public static Map<String, String> metadataToMap(Metadata metadata) {
-    Map<String, String> mapHeaders = new LinkedHashMap(metadata.keys().size());
+    Map<String, String> mapHeaders = new LinkedHashMap<>(metadata.keys().size());
     for (String key : metadata.keys()) {
       if (key.endsWith(Metadata.BINARY_HEADER_SUFFIX)) {
         continue;

instrumentation/grpc-1.5/src/main/java/io/opentelemetry/instrumentation/hypertrace/grpc/v1_5/server/GrpcServerInterceptor.java

@@ -56,7 +56,9 @@ public <ReqT, RespT> ServerCall.Listener<ReqT> interceptCall(
         FilterProvider.getFilterEvaluator().evaluateRequestHeaders(currentSpan, mapHeaders);
     if (filterResult.blockExecution()) {
       call.close(Status.PERMISSION_DENIED, new Metadata());
-      return NoopServerCallListener.INSTANCE;
+      @SuppressWarnings("unchecked")
+      ServerCall.Listener<ReqT> noop = NoopServerCallListener.INSTANCE;
+      return noop;
     }
 
     Listener<ReqT> serverCall = next.startCall(new TracingServerCall<>(call, currentSpan), headers);

instrumentation/servlet/servlet-2.3/src/main/java/io/opentelemetry/instrumentation/hypertrace/servlet/v2_3/Servlet2BodyInstrumentation.java

@@ -159,6 +159,7 @@ public static Object start(
       ServletSpanDecorator.addSessionId(currentSpan, httpRequest);
 
       // set request headers
+      @SuppressWarnings("unchecked")
       Enumeration<String> headerNames = httpRequest.getHeaderNames();
       Map<String, String> headers = new HashMap<>();
       while (headerNames.hasMoreElements()) {