Make equality checks defensive to null reference

See gh-19540

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/util/ResourceUtils.java

@@ -102,7 +102,7 @@ public abstract class ResourceUtils {
 		List<String> result = new ArrayList<>();
 		for (Resource resource : resources) {
 			if (resource.exists()) {
-				if (resource.getURI().getScheme().equals("file") && resource.getFile().isDirectory()) {
+				if ("file".equals(resource.getURI().getScheme()) && resource.getFile().isDirectory()) {
 					result.addAll(getChildFiles(resource));
 					continue;
 				}
@@ -124,7 +124,7 @@ public abstract class ResourceUtils {
 	}
 
 	private static String absolutePath(Resource resource) throws IOException {
-		if (!resource.getURI().getScheme().equals("file")) {
+		if (!"file".equals(resource.getURI().getScheme())) {
 			return resource.getURL().toExternalForm();
 		}
 		return resource.getFile().getAbsoluteFile().toURI().toString();

spring-boot-project/spring-boot-test-autoconfigure/src/main/java/org/springframework/boot/test/autoconfigure/restdocs/RestDocsWebTestClientBuilderCustomizer.java

@@ -61,7 +61,7 @@ class RestDocsWebTestClientBuilderCustomizer implements WebTestClientBuilderCust
 		if (port == null) {
 			return true;
 		}
-		return (scheme.equals("http") && port == 80) || (scheme.equals("https") && port == 443);
+		return ("http".equals(scheme) && port == 80) || ("https".equals(scheme) && port == 443);
 	}
 
 }

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/tasks/bundling/LoaderZipEntries.java

@@ -50,7 +50,7 @@ class LoaderZipEntries {
 				getClass().getResourceAsStream("/META-INF/loader/spring-boot-loader.jar"))) {
 			java.util.zip.ZipEntry entry = loaderJar.getNextEntry();
 			while (entry != null) {
-				if (entry.isDirectory() && !entry.getName().equals("META-INF/")) {
+				if (entry.isDirectory() && !"META-INF/".equals(entry.getName())) {
 					writeDirectory(new ZipArchiveEntry(entry), zipOutputStream);
 					writtenDirectoriesSpec.add(entry);
 				}

spring-boot-project/spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/Repackager.java

@@ -369,12 +369,12 @@ public class Repackager {
 
 		@Override
 		public JarArchiveEntry transform(JarArchiveEntry entry) {
-			if (entry.getName().equals("META-INF/INDEX.LIST")) {
+			if ("META-INF/INDEX.LIST".equals(entry.getName())) {
 				return null;
 			}
-			if ((entry.getName().startsWith("META-INF/") && !entry.getName().equals("META-INF/aop.xml")
+			if ((entry.getName().startsWith("META-INF/") && !"META-INF/aop.xml".equals(entry.getName())
 					&& !entry.getName().endsWith(".kotlin_module")) || entry.getName().startsWith("BOOT-INF/")
-					|| entry.getName().equals("module-info.class")) {
+					|| "module-info.class".equals(entry.getName())) {
 				return entry;
 			}
 			JarArchiveEntry renamedEntry = new JarArchiveEntry(this.namePrefix + entry.getName());