Migrate remaining use of ClassLoader.loadClass to Class.forName

Closes gh-19824

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/compiler/DependencyCustomizer.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.
@@ -93,7 +93,7 @@ public class DependencyCustomizer {
 			protected boolean canAdd() {
 				for (String className : classNames) {
 					try {
-						DependencyCustomizer.this.loader.loadClass(className);
+						Class.forName(className, false, DependencyCustomizer.this.loader);
 					}
 					catch (Exception ex) {
 						return true;
@@ -116,7 +116,7 @@ public class DependencyCustomizer {
 			protected boolean canAdd() {
 				for (String className : classNames) {
 					try {
-						DependencyCustomizer.this.loader.loadClass(className);
+						Class.forName(className, false, DependencyCustomizer.this.loader);
 						return false;
 					}
 					catch (Exception ex) {

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/RestartLauncher.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.
@@ -44,7 +44,7 @@ class RestartLauncher extends Thread {
 	@Override
 	public void run() {
 		try {
-			Class<?> mainClass = getContextClassLoader().loadClass(this.mainClassName);
+			Class<?> mainClass = Class.forName(this.mainClassName, false, getContextClassLoader());
 			Method mainMethod = mainClass.getDeclaredMethod("main", String[].class);
 			mainMethod.invoke(null, new Object[] { this.args });
 		}

spring-boot-project/spring-boot-devtools/src/main/java/org/springframework/boot/devtools/restart/classloader/RestartClassLoader.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.
@@ -141,7 +141,7 @@ public class RestartClassLoader extends URLClassLoader implements SmartClassLoad
 					loadedClass = findClass(name);
 				}
 				catch (ClassNotFoundException ex) {
-					loadedClass = getParent().loadClass(name);
+					loadedClass = Class.forName(name, false, getParent());
 				}
 			}
 			if (resolve) {

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

@@ -43,7 +43,7 @@ public class MainMethodRunner {
 	}
 
 	public void run() throws Exception {
-		Class<?> mainClass = Thread.currentThread().getContextClassLoader().loadClass(this.mainClassName);
+		Class<?> mainClass = Class.forName(this.mainClassName, false, Thread.currentThread().getContextClassLoader());
 		Method mainMethod = mainClass.getDeclaredMethod("main", String[].class);
 		mainMethod.setAccessible(true);
 		mainMethod.invoke(null, new Object[] { this.args });

spring-boot-project/spring-boot-tools/spring-boot-test-support/src/main/java/org/springframework/boot/testsupport/classpath/ModifiedClassPathClassLoader.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.
@@ -76,7 +76,7 @@ final class ModifiedClassPathClassLoader extends URLClassLoader {
 	@Override
 	public Class<?> loadClass(String name) throws ClassNotFoundException {
 		if (name.startsWith("org.junit") || name.startsWith("org.hamcrest")) {
-			return this.junitLoader.loadClass(name);
+			return Class.forName(name, false, this.junitLoader);
 		}
 		return super.loadClass(name);
 	}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/diagnostics/analyzer/NoSuchMethodFailureAnalyzer.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.
@@ -106,7 +106,8 @@ class NoSuchMethodFailureAnalyzer extends AbstractFailureAnalyzer<NoSuchMethodEr
 
 	private URL getActual(String className) {
 		try {
-			return getClass().getClassLoader().loadClass(className).getProtectionDomain().getCodeSource().getLocation();
+			return Class.forName(className, false, getClass().getClassLoader()).getProtectionDomain().getCodeSource()
+					.getLocation();
 		}
 		catch (Throwable ex) {
 			return null;