Revert "GH-3873: Deprecate JUnit 4 utilities in the project"

This reverts commit 2da4d5d.

Signed-off-by: chickenchickenlove <[email protected]>

Author: chickenchickenlove

build.gradle

@@ -57,6 +57,7 @@ ext {
 	hibernateValidationVersion = '8.0.2.Final'
 	jacksonBomVersion = '2.18.3'
 	jaywayJsonPathVersion = '2.9.0'
+	junit4Version = '4.13.2'
 	junitJupiterVersion = '5.12.2'
 	kafkaVersion = '4.0.0'
 	kotlinCoroutinesVersion = '1.10.2'
@@ -377,6 +378,9 @@ project ('spring-kafka-test') {
 		api 'org.junit.platform:junit-platform-launcher'
 		optionalApi "org.hamcrest:hamcrest-core:$hamcrestVersion"
 		optionalApi "org.mockito:mockito-core:$mockitoVersion"
+		optionalApi ("junit:junit:$junit4Version") {
+			exclude group: 'org.hamcrest', module: 'hamcrest-core'
+		}
 		optionalApi "org.apache.logging.log4j:log4j-core:$log4jVersion"
 	}
 }

spring-kafka-test/src/main/java/org/springframework/kafka/test/extensions/package-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2025 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -14,34 +14,32 @@
  * limitations under the License.
  */
 
-package org.springframework.kafka.test.extensions;
+package org.springframework.kafka.test.rule;
 
-import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
 import org.apache.logging.log4j.Level;
-import org.junit.jupiter.api.extension.ExtensionContext;
-import org.junit.jupiter.api.extension.InvocationInterceptor;
-import org.junit.jupiter.api.extension.ReflectiveInvocationContext;
+import org.junit.rules.MethodRule;
+import org.junit.runners.model.FrameworkMethod;
+import org.junit.runners.model.Statement;
 
 import org.springframework.kafka.test.utils.JUnitUtils;
 import org.springframework.kafka.test.utils.JUnitUtils.LevelsContainer;
 
 /**
- * A JUnit extension @ that changes the logger level for a set of classes
+ * A JUnit method @Rule that changes the logger level for a set of classes
  * while a test method is running. Useful for performance or scalability tests
  * where we don't want to generate a large log in a tight inner loop.
  *
  * @author Dave Syer
  * @author Artem Bilan
  * @author Gary Russell
- * @author Sanghyoek An
  *
  */
-public class Log4j2LevelAdjuster implements InvocationInterceptor {
+public class Log4j2LevelAdjuster implements MethodRule {
 
 	private final List<Class<?>> classes;
 
@@ -62,25 +60,25 @@ public Log4j2LevelAdjuster categories(String... categoriesToAdjust) {
 	}
 
 	@Override
-	public void interceptTestMethod(Invocation<Void> invocation,
-									ReflectiveInvocationContext<Method> invocationContext,
-									ExtensionContext extensionContext) throws Throwable {
-		String methodName = extensionContext.getRequiredTestMethod().getName();
-		LevelsContainer container = null;
-
-		try {
-			container = JUnitUtils.adjustLogLevels(
-					methodName,
-					Log4j2LevelAdjuster.this.classes,
-					Log4j2LevelAdjuster.this.categories,
-					Log4j2LevelAdjuster.this.level);
-			invocation.proceed();
-		}
-		finally {
-			if (container != null) {
-				JUnitUtils.revertLevels(methodName, container);
+	public Statement apply(final Statement base, FrameworkMethod method, Object target) {
+		return new Statement() {
+			@Override
+			public void evaluate() throws Throwable {
+				LevelsContainer container = null;
+				try {
+					container = JUnitUtils.adjustLogLevels(method.getName(),
+							Log4j2LevelAdjuster.this.classes, Log4j2LevelAdjuster.this.categories,
+							Log4j2LevelAdjuster.this.level);
+					base.evaluate();
+				}
+				finally {
+					if (container != null) {
+						JUnitUtils.revertLevels(method.getName(), container);
+					}
+				}
 			}
-		}
+
+		};
 	}
 
 }

spring-kafka-test/src/main/java/org/springframework/kafka/test/extensions/Log4j2LevelAdjuster.java renamed to spring-kafka-test/src/main/java/org/springframework/kafka/test/rule/Log4j2LevelAdjuster.java

@@ -0,0 +1,5 @@
+/**
+ * Provides JUnit rules.
+ */
+@org.jspecify.annotations.NullMarked
+package org.springframework.kafka.test.rule;

spring-kafka-test/src/main/java/org/springframework/kafka/test/rule/package-info.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.kafka.test.extensions;
+package org.springframework.kafka.test.rule;
 
 import java.io.IOException;
 import java.net.ServerSocket;