GH-3132: Remove usage of super();

Fixes https://github.com/spring-projects/spring-integration/issues/3132

It turns out that Checkstyle EmptyBlock doesn't complain about
empty default ctor.
Plus a new check for `super();` call treats it as a violation

* Remove `super();` from all the no-arg ctors
* Code style clean up in the affected classes according
IDEA suggestions

* Fix new Sonar smells

spring-integration-http/src/main/java/org/springframework/integration/http/config/HttpContextUtils.java

@@ -30,12 +30,12 @@ import org.springframework.web.bind.annotation.RequestMapping;
  *
  * @author Artem Bilan
  * @author Gary Russell
+ *
  * @since 3.0
  */
 public final class HttpContextUtils {
 
 	private HttpContextUtils() {
-		super();
 	}
 
 	/**

spring-integration-http/src/main/java/org/springframework/integration/http/dsl/Http.java

@@ -26,7 +26,6 @@ import org.springframework.integration.http.inbound.HttpRequestHandlingControlle
 import org.springframework.integration.http.inbound.HttpRequestHandlingMessagingGateway;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 import org.springframework.web.client.RestTemplate;
 
 /**
@@ -111,6 +110,7 @@ public final class Http {
 	 */
 	public static <P> HttpMessageHandlerSpec outboundChannelAdapter(Function<Message<P>, ?> uriFunction,
 			RestTemplate restTemplate) {
+
 		return outboundChannelAdapter(new FunctionExpression<>(uriFunction), restTemplate);
 	}
 
@@ -198,6 +198,7 @@ public final class Http {
 	 */
 	public static <P> HttpMessageHandlerSpec outboundGateway(Function<Message<P>, ?> uriFunction,
 			RestTemplate restTemplate) {
+
 		return outboundGateway(new FunctionExpression<>(uriFunction), restTemplate);
 	}
 
@@ -221,7 +222,7 @@ public final class Http {
 	 * @return the HttpControllerEndpointSpec instance
 	 */
 	public static HttpControllerEndpointSpec inboundControllerAdapter(String viewName, String... path) {
-		Assert.isTrue(StringUtils.hasText(viewName), "View name must not be empty");
+		Assert.hasText(viewName, "View name must not be empty");
 		return inboundControllerAdapter(new LiteralExpression(viewName), path);
 	}
 
@@ -246,7 +247,7 @@ public final class Http {
 	 * @return the HttpControllerEndpointSpec instance
 	 */
 	public static HttpControllerEndpointSpec inboundControllerGateway(String viewName, String... path) {
-		Assert.isTrue(StringUtils.hasText(viewName), "View name must not be empty");
+		Assert.hasText(viewName, "View name must not be empty");
 		return inboundControllerGateway(new LiteralExpression(viewName), path);
 	}
 
@@ -285,7 +286,6 @@ public final class Http {
 	}
 
 	private Http() {
-		super();
 	}
 
 }

spring-integration-http/src/main/java/org/springframework/integration/http/dsl/HttpInboundEndpointSupportSpec.java

@@ -190,7 +190,7 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 	 */
 	public S mappedRequestHeaders(String... patterns) {
 		Assert.isNull(this.explicitHeaderMapper,
-				"The 'mappedRequestHeaders' must be specified on the provided 'headerMapper': "
+				() -> "The 'mappedRequestHeaders' must be specified on the provided 'headerMapper': "
 						+ this.explicitHeaderMapper);
 		((DefaultHttpHeaderMapper) this.headerMapper).setInboundHeaderNames(patterns);
 		return _this();
@@ -204,7 +204,7 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 	 */
 	public S mappedResponseHeaders(String... patterns) {
 		Assert.isNull(this.explicitHeaderMapper,
-				"The 'mappedRequestHeaders' must be specified on the provided 'headerMapper': "
+				() -> "The 'mappedRequestHeaders' must be specified on the provided 'headerMapper': "
 						+ this.explicitHeaderMapper);
 		((DefaultHttpHeaderMapper) this.headerMapper).setOutboundHeaderNames(patterns);
 		return _this();
@@ -214,7 +214,7 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 	 * Specify the type of payload to be generated when the inbound HTTP request content is read by the
 	 * {@link org.springframework.http.converter.HttpMessageConverter}s.
 	 * By default this value is null which means at runtime any "text" Content-Type will
-	 * result in String while all others default to <code>byte[].class</code>.
+	 * result in String while all others default to {@code byte[].class}.
 	 * @param requestPayloadType The payload type.
 	 * @return the current Spec.
 	 */
@@ -227,7 +227,7 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 	 * Specify the type of payload to be generated when the inbound HTTP request content is read by the
 	 * {@link org.springframework.http.converter.HttpMessageConverter}s.
 	 * By default this value is null which means at runtime any "text" Content-Type will
-	 * result in String while all others default to <code>byte[].class</code>.
+	 * result in String while all others default to {@code byte[].class}.
 	 * @param requestPayloadType The payload type.
 	 * @return the current Spec.
 	 */
@@ -373,7 +373,6 @@ public abstract class HttpInboundEndpointSupportSpec<S extends HttpInboundEndpoi
 		private final CrossOrigin crossOrigin = new CrossOrigin();
 
 		CrossOriginSpec() {
-			super();
 		}
 
 		/**