Fix new Sonar smells

* Some code clean up in the affected classes

spring-integration-http/src/main/java/org/springframework/integration/http/inbound/BaseHttpInboundEndpoint.java

@@ -36,6 +36,7 @@ import org.springframework.integration.gateway.MessagingGatewaySupport;
 import org.springframework.integration.http.support.DefaultHttpHeaderMapper;
 import org.springframework.integration.http.support.IntegrationWebExchangeBindException;
 import org.springframework.integration.mapping.HeaderMapper;
+import org.springframework.lang.Nullable;
 import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -190,7 +191,7 @@ public class BaseHttpInboundEndpoint extends MessagingGatewaySupport implements
 	 * Specify the type of payload to be generated when the inbound HTTP request
 	 * content is read by the converters/encoders.
 	 * 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.
 	 */
 	public void setRequestPayloadTypeClass(Class<?> requestPayloadType) {
@@ -201,7 +202,7 @@ public class BaseHttpInboundEndpoint extends MessagingGatewaySupport implements
 	 * Specify the type of payload to be generated when the inbound HTTP request
 	 * content is read by the converters/encoders.
 	 * 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.
 	 */
 	public void setRequestPayloadType(ResolvableType requestPayloadType) {
@@ -350,15 +351,6 @@ public class BaseHttpInboundEndpoint extends MessagingGatewaySupport implements
 		return this.expectReply ? super.getIntegrationPatternType() : IntegrationPatternType.inbound_channel_adapter;
 	}
 
-	/**
-	 * Checks if the request has a readable body (not a GET, HEAD, or OPTIONS request).
-	 * @param httpMethod the HTTP method to check
-	 * @return true or false if HTTP request can contain the body
-	 */
-	protected boolean isReadable(HttpMethod httpMethod) {
-		return !(CollectionUtils.containsInstance(NON_READABLE_BODY_HTTP_METHODS, httpMethod));
-	}
-
 	protected void validate(Object value) {
 		BeanPropertyBindingResult errors = new BeanPropertyBindingResult(value, "requestPayload");
 		ValidationUtils.invokeValidator(this.validator, value, errors);
@@ -367,4 +359,13 @@ public class BaseHttpInboundEndpoint extends MessagingGatewaySupport implements
 		}
 	}
 
+	/**
+	 * Checks if the request has a readable body (not a GET, HEAD, or OPTIONS request).
+	 * @param httpMethod the HTTP method to check
+	 * @return true or false if HTTP request can contain the body
+	 */
+	protected static boolean isReadable(@Nullable HttpMethod httpMethod) {
+		return !(CollectionUtils.containsInstance(NON_READABLE_BODY_HTTP_METHODS, httpMethod));
+	}
+
 }

spring-integration-jpa/src/main/java/org/springframework/integration/jpa/support/parametersource/ExpressionEvaluatingParameterSourceFactory.java

@@ -68,10 +68,7 @@ public class ExpressionEvaluatingParameterSourceFactory implements ParameterSour
 	 */
 	public void setParameters(List<JpaParameter> parameters) {
 		Assert.notEmpty(parameters, "parameters must not be null or empty.");
-
-		for (JpaParameter parameter : parameters) {
-			Assert.notNull(parameter, "The provided list (parameters) cannot contain null values.");
-		}
+		Assert.noNullElements(parameters, "The provided list (parameters) cannot contain null values.");
 
 		this.parameters.addAll(parameters);
 		this.expressionEvaluator.getEvaluationContext().setVariable("staticParameters",
@@ -108,12 +105,11 @@ public class ExpressionEvaluatingParameterSourceFactory implements ParameterSour
 				this.parametersMap.put(parameter.getName(), parameter);
 			}
 			this.values.putAll(ExpressionEvaluatingParameterSourceUtils.convertStaticParameters(parameters));
-
 		}
 
 		@Override
+		@Nullable
 		public Object getValueByPosition(int position) {
-
 			Assert.isTrue(position >= 0, "The position must be non-negative.");
 
 			if (position <= this.parameters.size()) {
@@ -148,10 +144,10 @@ public class ExpressionEvaluatingParameterSourceFactory implements ParameterSour
 			}
 
 			return null;
-
 		}
 
 		@Override
+		@Nullable
 		public Object getValue(String paramName) {
 			if (this.values.containsKey(paramName)) {
 				return this.values.get(paramName);

spring-integration-webflux/src/main/java/org/springframework/integration/webflux/inbound/WebFluxInboundEndpoint.java

@@ -167,13 +167,14 @@ public class WebFluxInboundEndpoint extends BaseHttpInboundEndpoint implements W
 	}
 
 	private Mono<?> extractRequestBody(ServerWebExchange exchange) {
-		if (isReadable(exchange.getRequest().getMethod())) {
+		ServerHttpRequest request = exchange.getRequest();
+		if (isReadable(request.getMethod())) {
 			return extractReadableRequestBody(exchange)
 					.cast(Object.class)
-					.switchIfEmpty(queryParams(exchange));
+					.switchIfEmpty(queryParams(request));
 		}
 		else {
-			return queryParams(exchange);
+			return queryParams(request);
 		}
 	}
 
@@ -515,8 +516,8 @@ public class WebFluxInboundEndpoint extends BaseHttpInboundEndpoint implements W
 		return (mediaTypes != null ? new ArrayList<>(mediaTypes) : producibleTypesSupplier.get());
 	}
 
-	private static Mono<?> queryParams(ServerWebExchange exchange) {
-		return Mono.just(exchange.getRequest().getQueryParams());
+	private static Mono<?> queryParams(ServerHttpRequest request) {
+		return Mono.just(request.getQueryParams());
 	}
 
 	private static MediaType selectMoreSpecificMediaType(MediaType acceptable, MediaType producible) {