Make inner classes in tests static where feasible

Closes gh-36939

Signed-off-by: Yanming Zhou <zhouyanming@gmail.com>

spring-beans/src/test/java/org/springframework/beans/BeanWrapperGenericsTests.java

@@ -687,7 +687,7 @@ class BeanWrapperGenericsTests {
 	}
 
 
-	public class Bar implements Foo {
+	public static class Bar implements Foo {
 
 		private double version;
 
@@ -710,7 +710,7 @@ class BeanWrapperGenericsTests {
 	}
 
 
-	public class Promotion implements ObjectWithId<Long> {
+	public static class Promotion implements ObjectWithId<Long> {
 
 		private Long id;
 

spring-beans/src/test/java/org/springframework/beans/ExtendedBeanInfoTests.java

@@ -934,7 +934,7 @@ class ExtendedBeanInfoTests {
 	}
 
 
-	abstract class Library {
+	abstract static class Library {
 
 		public Book getBook() {
 			return null;
@@ -945,7 +945,7 @@ class ExtendedBeanInfoTests {
 	}
 
 
-	class LawLibrary extends Library implements TextBookOperations {
+	static class LawLibrary extends Library implements TextBookOperations {
 
 		@Override
 		public LawBook getBook() {

spring-beans/src/test/java/org/springframework/beans/factory/support/AutowireUtilsTests.java

@@ -82,7 +82,7 @@ class AutowireUtilsTests {
 	public interface MyInterfaceType<T> {
 	}
 
-	public class MySimpleInterfaceType implements MyInterfaceType<String> {
+	public static class MySimpleInterfaceType implements MyInterfaceType<String> {
 	}
 
 	public static class MyTypeWithMethods<T> {

spring-context/src/test/java/org/springframework/scheduling/config/ScheduledTaskTests.java

@@ -95,7 +95,7 @@ class ScheduledTaskTests {
 		assertThat(scheduledTask.nextExecution()).isNull();
 	}
 
-	class CountingRunnable implements Runnable {
+	static class CountingRunnable implements Runnable {
 
 		int executionCount;
 

spring-context/src/test/java/org/springframework/validation/beanvalidation/SpringValidatorAdapterTests.java

@@ -525,7 +525,7 @@ class SpringValidatorAdapterTests {
 	}
 
 
-	public class BeanWithListElementConstraint {
+	public static class BeanWithListElementConstraint {
 
 		@Valid
 		private List<@NotNull String> property;
@@ -540,7 +540,7 @@ class SpringValidatorAdapterTests {
 	}
 
 
-	public class BeanWithMapEntryConstraint {
+	public static class BeanWithMapEntryConstraint {
 
 		@Valid
 		private Map<@NotNull String, @NotNull String> property;

spring-core/src/test/java/org/springframework/core/ExceptionDepthComparatorTests.java

@@ -89,23 +89,23 @@ class ExceptionDepthComparatorTests {
 	}
 
 	@SuppressWarnings("serial")
-	public class HighestDepthException extends Throwable {
+	public static class HighestDepthException extends Throwable {
 	}
 
 	@SuppressWarnings("serial")
-	public class LowestDepthException extends HighestDepthException {
+	public static class LowestDepthException extends HighestDepthException {
 	}
 
 	@SuppressWarnings("serial")
-	public class TargetException extends LowestDepthException {
+	public static class TargetException extends LowestDepthException {
 	}
 
 	@SuppressWarnings("serial")
-	public class SameDepthException extends LowestDepthException {
+	public static class SameDepthException extends LowestDepthException {
 	}
 
 	@SuppressWarnings("serial")
-	public class NoDepthException extends TargetException {
+	public static class NoDepthException extends TargetException {
 	}
 
 }

spring-core/src/test/java/org/springframework/core/GenericTypeResolverTests.java

@@ -260,25 +260,25 @@ class GenericTypeResolverTests {
 	public interface MyInterfaceType<T> {
 	}
 
-	public class MySimpleInterfaceType implements MyInterfaceType<String> {
+	public static class MySimpleInterfaceType implements MyInterfaceType<String> {
 	}
 
-	public class MyCollectionInterfaceType implements MyInterfaceType<Collection<String>> {
+	public static class MyCollectionInterfaceType implements MyInterfaceType<Collection<String>> {
 	}
 
-	public abstract class MyAbstractType<T> implements MyInterfaceType<T> {
+	public abstract static class MyAbstractType<T> implements MyInterfaceType<T> {
 	}
 
-	public class MyConcreteType extends MyAbstractType<Character> {
+	public static class MyConcreteType extends MyAbstractType<Character> {
 	}
 
-	public abstract class MySuperclassType<T> {
+	public abstract static class MySuperclassType<T> {
 	}
 
-	public class MySimpleSuperclassType extends MySuperclassType<String> {
+	public static class MySimpleSuperclassType extends MySuperclassType<String> {
 	}
 
-	public class MyCollectionSuperclassType extends MySuperclassType<Collection<String>> {
+	public static class MyCollectionSuperclassType extends MySuperclassType<Collection<String>> {
 	}
 
 	public static class MyTypeWithMethods<T> {
@@ -380,19 +380,19 @@ class GenericTypeResolverTests {
 	static class GenericClass<T> {
 	}
 
-	class A {}
+	static class A {}
 
-	class B<T> {}
+	static class B<T> {}
 
-	class C extends A {}
+	static class C extends A {}
 
-	class D extends B<Long> {}
+	static class D extends B<Long> {}
 
-	class E extends C {}
+	static class E extends C {}
 
-	class TestIfc<T> {}
+	static class TestIfc<T> {}
 
-	class TestImpl<I extends A, T extends B<I>> extends TestIfc<T> {
+	static class TestImpl<I extends A, T extends B<I>> extends TestIfc<T> {
 	}
 
 	abstract static class BiGenericClass<T extends B<?>, V extends A> {}

spring-core/src/test/java/org/springframework/core/ResolvableTypeTests.java

@@ -1773,7 +1773,7 @@ class ResolvableTypeTests {
 	public interface MyInterfaceType<T> {
 	}
 
-	public class MyGenericInterfaceType<T> implements MyInterfaceType<T>, ResolvableTypeProvider {
+	public static class MyGenericInterfaceType<T> implements MyInterfaceType<T>, ResolvableTypeProvider {
 
 		private final Class<T> type;
 
@@ -1790,26 +1790,26 @@ class ResolvableTypeTests {
 		}
 	}
 
-	public class MySimpleInterfaceType implements MyInterfaceType<String> {
+	public static class MySimpleInterfaceType implements MyInterfaceType<String> {
 	}
 
-	public abstract class MySimpleInterfaceTypeWithImplementsRaw implements MyInterfaceType<String>, List {
+	public abstract static class MySimpleInterfaceTypeWithImplementsRaw implements MyInterfaceType<String>, List {
 	}
 
-	public abstract class ExtendsMySimpleInterfaceTypeWithImplementsRaw extends MySimpleInterfaceTypeWithImplementsRaw {
+	public abstract static class ExtendsMySimpleInterfaceTypeWithImplementsRaw extends MySimpleInterfaceTypeWithImplementsRaw {
 	}
 
-	public class MyCollectionInterfaceType implements MyInterfaceType<Collection<String>> {
+	public static class MyCollectionInterfaceType implements MyInterfaceType<Collection<String>> {
 	}
 
 
-	public abstract class MySuperclassType<T> {
+	public abstract static class MySuperclassType<T> {
 	}
 
-	public class MySimpleSuperclassType extends MySuperclassType<String> {
+	public static class MySimpleSuperclassType extends MySuperclassType<String> {
 	}
 
-	public class MyCollectionSuperclassType extends MySuperclassType<Collection<String>> {
+	public static class MyCollectionSuperclassType extends MySuperclassType<Collection<String>> {
 	}
 
 
@@ -1819,22 +1819,22 @@ class ResolvableTypeTests {
 	private static class SubConsumer<N extends Number> implements Consumer<N> {
 	}
 
-	public class Wildcard<T extends CharSequence> {
+	public static class Wildcard<T extends CharSequence> {
 	}
 
-	public class WildcardFixed extends Wildcard<String> {
+	public static class WildcardFixed extends Wildcard<String> {
 	}
 
-	public class WildcardConsumer<T extends CharSequence & Serializable> implements Consumer<Wildcard<T>> {
+	public static class WildcardConsumer<T extends CharSequence & Serializable> implements Consumer<Wildcard<T>> {
 	}
 
-	public class DoubleWildcard<T extends CharSequence & Serializable> {
+	public static class DoubleWildcard<T extends CharSequence & Serializable> {
 	}
 
-	public class DoubleWildcardFixed extends DoubleWildcard<String> {
+	public static class DoubleWildcardFixed extends DoubleWildcard<String> {
 	}
 
-	public class DoubleWildcardConsumer<T extends CharSequence & Serializable> implements Consumer<DoubleWildcard<T>> {
+	public static class DoubleWildcardConsumer<T extends CharSequence & Serializable> implements Consumer<DoubleWildcard<T>> {
 	}
 
 
@@ -1853,10 +1853,10 @@ class ResolvableTypeTests {
 	}
 
 
-	class Foo<T extends Foo<T>> {
+	static class Foo<T extends Foo<T>> {
 	}
 
-	class Bar extends Foo<Bar> {
+	static class Bar extends Foo<Bar> {
 	}
 
 
@@ -1888,19 +1888,19 @@ class ResolvableTypeTests {
 	public interface IBase<BT extends IBase<BT>> {
 	}
 
-	public abstract class AbstractBase<BT extends IBase<BT>> implements IBase<BT> {
+	public abstract static class AbstractBase<BT extends IBase<BT>> implements IBase<BT> {
 	}
 
-	public class BaseImplementation extends AbstractBase<BaseImplementation> {
+	public static class BaseImplementation extends AbstractBase<BaseImplementation> {
 	}
 
-	public class BaseProvider<BT extends IBase<BT>> implements IProvider<IBase<BT>> {
+	public static class BaseProvider<BT extends IBase<BT>> implements IProvider<IBase<BT>> {
 
 		public Collection<IBase<BT>> stuff;
 	}
 
 
-	public abstract class UnresolvedWithGenerics {
+	public abstract static class UnresolvedWithGenerics {
 
 		Set<Integer> set;
 	}

spring-core/src/test/java/org/springframework/core/annotation/AnnotatedElementUtilsTests.java

@@ -1519,7 +1519,7 @@ class AnnotatedElementUtilsTests {
 		@Nullable Object doIt();
 	}
 
-	class TransactionalServiceImpl implements TransactionalService {
+	static class TransactionalServiceImpl implements TransactionalService {
 
 		@Override
 		public @Nullable Object doIt() {

spring-core/src/test/java/org/springframework/core/annotation/MergedAnnotationsTests.java

@@ -2794,7 +2794,7 @@ class MergedAnnotationsTests {
 		void doIt();
 	}
 
-	class TransactionalServiceImpl implements TransactionalService {
+	static class TransactionalServiceImpl implements TransactionalService {
 
 		@Override
 		public void doIt() {
@@ -3289,8 +3289,7 @@ class MergedAnnotationsTests {
 	@interface DoublyComposedRootAnnotation {
 	}
 
-	class DomainType {
-
+	static class DomainType {
 		@RootAnnotation
 		Object directlyAnnotated;
 

spring-core/src/test/java/org/springframework/core/convert/TypeDescriptorTests.java

@@ -967,7 +967,7 @@ class TypeDescriptorTests {
 	}
 
 
-	public class IntegerType implements GenericType<Integer> {
+	public static class IntegerType implements GenericType<Integer> {
 
 		@Override
 		public Integer getProperty() {
@@ -989,7 +989,7 @@ class TypeDescriptorTests {
 	}
 
 
-	public class NumberType implements GenericType<Number> {
+	public static class NumberType implements GenericType<Number> {
 
 		@Override
 		public Integer getProperty() {

spring-core/src/test/java/org/springframework/core/convert/converter/DefaultConversionServiceTests.java

@@ -1195,7 +1195,7 @@ class DefaultConversionServiceTests {
 	}
 
 
-	public class ColorConverter implements Converter<String, Color> {
+	public static class ColorConverter implements Converter<String, Color> {
 
 		@Override
 		public Color convert(String source) {

spring-expression/src/test/java/org/springframework/expression/spel/SelectionAndProjectionTests.java

@@ -372,7 +372,7 @@ class SelectionAndProjectionTests {
 	/**
 	 * Simulates a custom {@link Iterable} which is itself not a {@link Collection}.
 	 */
-	class Counter implements Iterable<Integer> {
+	static class Counter implements Iterable<Integer> {
 
 		private final List<Integer> list = new ArrayList<>();
 

spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java

@@ -6744,7 +6744,7 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 	}
 
 
-	public class PayloadX {
+	public static class PayloadX {
 
 		public int valueI = 120;
 		public Integer valueIB = 120;
@@ -7456,7 +7456,7 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 	}
 
 
-	public class Reg {
+	public static class Reg {
 
 		private Integer _value,_value2;
 		private Long _valueL,_valueL2;

spring-tx/src/test/java/org/springframework/transaction/interceptor/AbstractReactiveTransactionAspectTests.java

@@ -387,7 +387,7 @@ public abstract class AbstractReactiveTransactionAspectTests {
 	}
 
 
-	public class DefaultTestBean implements TestBean {
+	public static class DefaultTestBean implements TestBean {
 
 		private String name;
 

spring-webflux/src/test/java/org/springframework/web/reactive/handler/CorsUrlHandlerMappingTests.java

@@ -194,7 +194,7 @@ class CorsUrlHandlerMappingTests {
 		}
 	}
 
-	public class CustomCorsConfigurationSource implements CorsConfigurationSource {
+	public static class CustomCorsConfigurationSource implements CorsConfigurationSource {
 
 		@Override
 		public CorsConfiguration getCorsConfiguration(ServerWebExchange exchange) {