Use isEmpty and polish diamond operator

Author: ngocnhan-tran1996

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/transaction/TransactionManagerCustomizers.java

@@ -59,8 +59,8 @@ public void customize(TransactionManager transactionManager) {
 	 * @since 3.2.0
 	 */
 	public static TransactionManagerCustomizers of(Collection<? extends TransactionManagerCustomizer<?>> customizers) {
-		return new TransactionManagerCustomizers((customizers != null) ? new ArrayList<>(customizers)
-				: Collections.<TransactionManagerCustomizer<?>>emptyList());
+		return new TransactionManagerCustomizers(
+				(customizers != null) ? new ArrayList<>(customizers) : Collections.emptyList());
 	}
 
 }

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/DispatcherServletPath.java

@@ -74,7 +74,7 @@ default String getPrefix() {
 	 * @return the path as a servlet URL mapping
 	 */
 	default String getServletUrlMapping() {
-		if (getPath().equals("") || getPath().equals("/")) {
+		if (getPath().isEmpty() || getPath().equals("/")) {
 			return "/";
 		}
 		if (getPath().contains("*")) {

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcProperties.java

@@ -237,7 +237,7 @@ public void setLoadOnStartup(int loadOnStartup) {
 		}
 
 		public String getServletMapping() {
-			if (this.path.equals("") || this.path.equals("/")) {
+			if (this.path.isEmpty() || this.path.equals("/")) {
 				return "/";
 			}
 			if (this.path.endsWith("/")) {

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/tomcat/TomcatWebServer.java

@@ -416,7 +416,7 @@ private String getContextPath() {
 			.map(TomcatEmbeddedContext.class::cast)
 			.filter(this::imperative)
 			.map(TomcatEmbeddedContext::getPath)
-			.map((path) -> path.equals("") ? "/" : path)
+			.map((path) -> path.isEmpty() ? "/" : path)
 			.collect(Collectors.joining(" "));
 		return StringUtils.hasText(contextPath) ? contextPath : null;
 	}