Make sure the generated values are available from a static context

This commit updates the tests of property values code generated to
invoke the generated code from a `static` context. This ensures that
the test fails if that's not the case.

This commit also updated LinkedHashMap handling that did suffer from
that problem.

Closes gh-34661

Author: snicoll

spring-beans/src/main/java/org/springframework/beans/factory/aot/BeanDefinitionPropertyValueCodeGeneratorDelegates.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -156,6 +156,8 @@ private CodeBlock generateLinkedHashMapCode(ValueCodeGenerator valueCodeGenerato
 						.builder(SuppressWarnings.class)
 						.addMember("value", "{\"rawtypes\", \"unchecked\"}")
 						.build());
+				method.addModifiers(javax.lang.model.element.Modifier.PRIVATE,
+						javax.lang.model.element.Modifier.STATIC);
 				method.returns(Map.class);
 				method.addStatement("$T map = new $T($L)", Map.class,
 						LinkedHashMap.class, map.size());

spring-beans/src/test/java/org/springframework/beans/factory/aot/BeanDefinitionPropertyValueCodeGeneratorDelegatesTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -18,6 +18,7 @@
 
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.lang.reflect.Method;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.time.temporal.ChronoUnit;
@@ -28,7 +29,6 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.function.BiConsumer;
-import java.util.function.Supplier;
 
 import javax.lang.model.element.Modifier;
 
@@ -54,7 +54,7 @@
 import org.springframework.core.testfixture.aot.generate.value.ExampleClass$$GeneratedBy;
 import org.springframework.javapoet.CodeBlock;
 import org.springframework.javapoet.MethodSpec;
-import org.springframework.javapoet.ParameterizedTypeName;
+import org.springframework.util.ReflectionUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -83,14 +83,23 @@ private void compile(Object value, BiConsumer<Object, Compiled> result) {
 		CodeBlock generatedCode = createValueCodeGenerator(generatedClass).generateCode(value);
 		typeBuilder.set(type -> {
 			type.addModifiers(Modifier.PUBLIC);
-			type.addSuperinterface(
-					ParameterizedTypeName.get(Supplier.class, Object.class));
-			type.addMethod(MethodSpec.methodBuilder("get").addModifiers(Modifier.PUBLIC)
+			type.addMethod(MethodSpec.methodBuilder("get").addModifiers(Modifier.PUBLIC, Modifier.STATIC)
 					.returns(Object.class).addStatement("return $L", generatedCode).build());
 		});
 		generationContext.writeGeneratedContent();
 		TestCompiler.forSystem().with(generationContext).compile(compiled ->
-				result.accept(compiled.getInstance(Supplier.class).get(), compiled));
+				result.accept(getGeneratedCodeReturnValue(compiled, generatedClass), compiled));
+	}
+
+	private static Object getGeneratedCodeReturnValue(Compiled compiled, GeneratedClass generatedClass) {
+		try {
+			Object instance = compiled.getInstance(Object.class, generatedClass.getName().reflectionName());
+			Method get = ReflectionUtils.findMethod(instance.getClass(), "get");
+			return get.invoke(null);
+		}
+		catch (Exception ex) {
+			throw new RuntimeException("Failed to invoke generated code '%s':".formatted(generatedClass.getName()), ex);
+		}
 	}
 
 	@Nested