Remove DisposableBeanMethodInterceptor

Previously, any @Configuration class was enhanced to namely implement
DisposableBean in order to remove static callbacks that were registered
for that class. This leads to problem if an ApplicationContext is created
and destroyed within the lifecycle on another ApplicationContext in the
same class loader.

It turns out that the destruction callback is no longer necessary as the
interceptors are now stateless: the VM is free to reclaim any of those if
necessary.

Issue: SPR-12445

spring-context/src/test/java/org/springframework/context/annotation/configuration/ConfigurationClassCglibCallbackDeregistrationTests.java

@@ -1,78 +0,0 @@
-/*
- * Copyright 2002-2012 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.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.context.annotation.configuration;
-
-import org.junit.Test;
-
-import org.springframework.beans.factory.DisposableBean;
-import org.springframework.context.annotation.AnnotationConfigApplicationContext;
-import org.springframework.context.annotation.Configuration;
-
-import static org.hamcrest.CoreMatchers.*;
-import static org.junit.Assert.*;
-
-/**
- * Tests ensuring that @Configuration-related CGLIB callbacks are de-registered
- * at container shutdown time, allowing for proper garbage collection. See SPR-7901.
- *
- * @author Chris Beams
- */
-public class ConfigurationClassCglibCallbackDeregistrationTests {
-
-	/**
-	 * asserting that the actual callback is deregistered is difficult,
-	 * but we can at least assert that the @Configuration class is enhanced
-	 * to implement DisposableBean. The enhanced implementation of destroy()
-	 * will do the de-registration work.
-	 */
-	@Test
-	public void destroyContext() {
-		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class);
-		Config config = ctx.getBean(Config.class);
-		assertThat(config, instanceOf(DisposableBean.class));
-		ctx.destroy();
-	}
-
-	/**
-	 * The DisposableBeanMethodInterceptor in ConfigurationClassEnhancer
-	 * should be careful to invoke any explicit super-implementation of
-	 * DisposableBean#destroy().
-	 */
-	@Test
-	public void destroyExplicitDisposableBeanConfig() {
-		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(DisposableConfig.class);
-		DisposableConfig config = ctx.getBean(DisposableConfig.class);
-		assertThat(config.destroyed, is(false));
-		ctx.destroy();
-		assertThat("DisposableConfig.destroy() was not invoked", config.destroyed, is(true));
-	}
-
-
-	@Configuration
-	static class Config {
-	}
-
-
-	@Configuration
-	static class DisposableConfig implements DisposableBean {
-		boolean destroyed = false;
-		@Override
-		public void destroy() throws Exception {
-			this.destroyed = true;
-		}
-	}
-}