diff --git a/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java b/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java
index 42514c24fd6a..7391ae6bda98 100644
--- a/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java
+++ b/buildSrc/src/main/java/org/springframework/boot/build/antora/GenerateAntoraPlaybook.java
@@ -175,7 +175,7 @@ private void addAntoraContentStartPaths(Set<String> startPaths) {
 	private void addDir(Map<String, Object> data) {
 		Path playbookDir = toRealPath(getOutputFile().get().getAsFile().toPath()).getParent();
 		Path outputDir = toRealPath(getProject().getBuildDir().toPath().resolve("site"));
-		data.put("output", Map.of("dir", "." + File.separator + playbookDir.relativize(outputDir).toString()));
+		data.put("output", Map.of("dir", "." + File.separator + playbookDir.relativize(outputDir)));
 	}
 
 	@SuppressWarnings("unchecked")
diff --git a/buildSrc/src/main/java/org/springframework/boot/build/bom/ManagedDependencies.java b/buildSrc/src/main/java/org/springframework/boot/build/bom/ManagedDependencies.java
index c9066aa053bd..cb6ca9581c3e 100644
--- a/buildSrc/src/main/java/org/springframework/boot/build/bom/ManagedDependencies.java
+++ b/buildSrc/src/main/java/org/springframework/boot/build/bom/ManagedDependencies.java
@@ -99,7 +99,7 @@ static ManagedDependencies ofBom(File bom) {
 
 	static String asId(String groupId, String artifactId, String version, String classifier) {
 		String id = groupId + ":" + artifactId + ":" + version;
-		if (classifier != null && classifier.length() > 0) {
+		if (classifier != null && !classifier.isEmpty()) {
 			id = id + ":" + classifier;
 		}
 		return id;
diff --git a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java
index 49389aebb264..51f07bcd69ef 100644
--- a/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java
+++ b/spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java
@@ -235,7 +235,7 @@ private ConfigurationPropertiesBeanDescriptor describeBean(ObjectMapper mapper,
 	@SuppressWarnings({ "unchecked" })
 	private Map<String, Object> safeSerialize(ObjectMapper mapper, Object bean, String prefix) {
 		try {
-			return new HashMap<>(mapper.convertValue(bean, Map.class));
+			return new HashMap<String, Object>(mapper.convertValue(bean, Map.class));
 		}
 		catch (Exception ex) {
 			return new HashMap<>(Collections.singletonMap("error", "Cannot serialize '" + prefix + "'"));