chore(pmd): enable GuardLogStatement rule

Notes:
- false positives were suppressed until we have PMD >= 6.36.0 (see #1250)
- ThymeleafViewResolverInitializingBean: a check for null was removed because IDEA said that the
  result is always false because getBean() throws exception when there is no bean. I haven't add
  try-catch and let it fails in order to not miss such case (if it happens)

Author: php-coder

src/main/config/pmd.xml

@@ -21,6 +21,12 @@
 	<rule ref="category/java/bestpractices.xml/ConstantsInInterface" />
 	<rule ref="category/java/bestpractices.xml/DefaultLabelNotLastInSwitchStmt" />
 	<rule ref="category/java/bestpractices.xml/ForLoopCanBeForeach" />
+	<rule ref="category/java/bestpractices.xml/GuardLogStatement">
+		<properties>
+			<property name="logLevels" value="trace,debug,info,warn,error" />
+			<property name="guardsMethods" value="isTraceEnabled,isDebugEnabled,isInfoEnabled,isWarnEnabled,isErrorEnabled" />
+		</properties>
+	</rule>
 	<!--<rule ref="category/java/bestpractices.xml/JUnit4SuitesShouldUseSuiteAnnotation" />-->
 	<rule ref="category/java/bestpractices.xml/JUnit4TestShouldUseAfterAnnotation" />
 	<rule ref="category/java/bestpractices.xml/JUnit4TestShouldUseBeforeAnnotation" />

src/main/java/ru/mystamps/web/feature/image/FilesystemImagePersistenceStrategy.java

@@ -51,7 +51,7 @@ public void init() {
 			log.warn("Directory '{}' doesn't exist! Image uploading won't work", storageDir);
 
 		} else if (!storageDir.canWrite()) {
-			log.warn(
+			log.warn( // NOPMD: GuardLogStatement (https://github.com/pmd/pmd/issues/957)
 				// FIXME(java9): log also user: ProcessHandle.current().info().user()
 				"Directory '{}' exists but isn't writable for the current user! "
 				+ "Image uploading won't work.",
@@ -69,7 +69,7 @@ public void init() {
 
 		} else if (!previewDir.canWrite()) {
 			// FIXME(java9): log also user: ProcessHandle.current().info().user()
-			log.warn(
+			log.warn( // NOPMD: GuardLogStatement (https://github.com/pmd/pmd/issues/957)
 				"Directory '{}' exists but isn't writable for the current user! "
 				+ "Image preview generation won't work",
 				previewDir

src/main/java/ru/mystamps/web/feature/series/DownloadImageInterceptor.java

@@ -89,7 +89,7 @@ public boolean preHandle(
 
 		if (!(request instanceof StandardMultipartHttpServletRequest)) {
 			// It could mean that <form> tag doesn't have enctype="multipart/form-data" attribute.
-			LOG.warn(
+			LOG.warn( // NOPMD: GuardLogStatement (https://github.com/pmd/pmd/issues/957)
 				"Unknown type of request ({}). "
 				+ "Downloading images from external servers won't work!",
 				request

src/main/java/ru/mystamps/web/feature/series/HttpURLConnectionDownloaderService.java

@@ -117,7 +117,7 @@ public DownloadResult download(String fileUrl) {
 	private static HttpURLConnection openConnection(URL url) throws IOException {
 		URLConnection connection = url.openConnection();
 		if (!(connection instanceof HttpURLConnection)) {
-			LOG.warn(
+			LOG.warn( // NOPMD: GuardLogStatement (https://github.com/pmd/pmd/issues/957)
 				"Couldn't open connection: "
 				+ "unknown type of connection class ({}). "
 				+ "Downloading files from external servers won't work!",

src/main/java/ru/mystamps/web/support/spring/boot/ThymeleafViewResolverInitializingBean.java

@@ -65,13 +65,6 @@ public class ThymeleafViewResolverInitializingBean
 	public void afterPropertiesSet() throws Exception {
 		ThymeleafViewResolver viewResolver =
 			applicationContext.getBean(ThymeleafViewResolver.class);
-		if (viewResolver == null) {
-			LOG.warn(
-				"Cannot adjust ThymeleafViewResolver: "
-				+ "bean of this type wasn't found in application context"
-			);
-			return;
-		}
 
 		Profiles prod = Profiles.of("prod");
 		boolean productionEnv = environment.acceptsProfiles(prod);