Allow configprops endpoint stringify primitive wrappers

Update `ConfigurationPropertiesReportEndpoint` so that primitive
wrapper input values in the Environment are stringified for display.

Fixes gh-36076

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java

@@ -394,7 +394,7 @@ public class ConfigurationPropertiesReportEndpoint implements ApplicationContext
 	}
 
 	private Object stringifyIfNecessary(Object value) {
-		if (value == null || value.getClass().isPrimitive()) {
+		if (value == null || ClassUtils.isPrimitiveOrWrapper(value.getClass()) || value instanceof String) {
 			return value;
 		}
 		if (CharSequence.class.isAssignableFrom(value.getClass())) {

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpointTests.java

@@ -44,7 +44,10 @@ import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.core.env.PropertySource;
 import org.springframework.mock.env.MockPropertySource;
 import org.springframework.util.unit.DataSize;
 
@@ -143,6 +146,21 @@ class ConfigurationPropertiesReportEndpointTests {
 				.isEqualTo(Duration.ofSeconds(10).toString())));
 	}
 
+	@Test // gh-36076
+	void descriptorWithWrapperProperty() {
+		this.contextRunner.withUserConfiguration(TestPropertiesConfiguration.class).withInitializer((context) -> {
+			ConfigurableEnvironment environment = context.getEnvironment();
+			Map<String, Object> map = Collections.singletonMap("test.wrapper", 10);
+			PropertySource<?> propertySource = new MapPropertySource("test", map);
+			environment.getPropertySources().addLast(propertySource);
+		})
+			.run(assertProperties("test", (properties) -> assertThat(properties.get("wrapper")).isEqualTo(10),
+					(inputs) -> {
+						Map<String, Object> wrapper = (Map<String, Object>) inputs.get("wrapper");
+						assertThat(wrapper.get("value")).isEqualTo(10);
+					}));
+	}
+
 	@Test
 	void descriptorWithNonCamelCaseProperty() {
 		this.contextRunner.withUserConfiguration(MixedCasePropertiesConfiguration.class)
@@ -476,6 +494,8 @@ class ConfigurationPropertiesReportEndpointTests {
 
 		private String ignored = "dummy";
 
+		private Integer wrapper;
+
 		public String getDbPassword() {
 			return this.dbPassword;
 		}
@@ -512,6 +532,14 @@ class ConfigurationPropertiesReportEndpointTests {
 			return this.ignored;
 		}
 
+		public Integer getWrapper() {
+			return this.wrapper;
+		}
+
+		public void setWrapper(Integer wrapper) {
+			this.wrapper = wrapper;
+		}
+
 	}
 
 	@Configuration(proxyBeanMethods = false)