Inner class may be static

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/ContextIdApplicationContextInitializer.java

@@ -72,7 +72,7 @@ private String getApplicationId(ConfigurableEnvironment environment) {
 	/**
 	 * The ID of a context.
 	 */
-	class ContextId {
+	static class ContextId {
 
 		private final AtomicLong children = new AtomicLong(0);
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigFileApplicationListener.java

@@ -259,7 +259,7 @@ public void setSearchNames(String names) {
 	 * {@link BeanFactoryPostProcessor} to re-order our property sources below any
 	 * {@code @PropertySource} items added by the {@link ConfigurationClassPostProcessor}.
 	 */
-	private class PropertySourceOrderingPostProcessor implements BeanFactoryPostProcessor, Ordered {
+	private static class PropertySourceOrderingPostProcessor implements BeanFactoryPostProcessor, Ordered {
 
 		private ConfigurableApplicationContext context;
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/info/InfoProperties.java

@@ -121,7 +121,7 @@ public void remove() {
 	/**
 	 * Property entry.
 	 */
-	public final class Entry {
+	public static final class Entry {
 
 		private final String key;
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/java/JavaLoggingSystem.java

@@ -168,7 +168,7 @@ public void cleanUp() {
 		this.configuredLoggers.clear();
 	}
 
-	private final class ShutdownHandler implements Runnable {
+	private static final class ShutdownHandler implements Runnable {
 
 		@Override
 		public void run() {