Polish "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

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

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

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

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