org.springframework.beans.factory.support.DefaultListableBeanFactory#preInstantiateSingletons ( )源码实例Demo

@Test
public void testWildcardCanBeUsedInNotificationListenersMap() throws Exception {
	String beanName = "charlesDexterWard";
	BeanDefinitionBuilder testBean = BeanDefinitionBuilder.rootBeanDefinition(JmxTestBean.class);

	DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
	factory.registerBeanDefinition(beanName, testBean.getBeanDefinition());
	factory.preInstantiateSingletons();
	Object testBeanInstance = factory.getBean(beanName);

	MBeanExporter exporter = new MBeanExporter();
	exporter.setServer(getServer());
	Map<String, Object> beansToExport = new HashMap<>();
	beansToExport.put("test:what=ever", testBeanInstance);
	exporter.setBeans(beansToExport);
	exporter.setBeanFactory(factory);
	StubNotificationListener listener = new StubNotificationListener();
	exporter.setNotificationListenerMappings(Collections.singletonMap("*", listener));

	start(exporter);
}
 

@Test
public void testWithStaticFactoryMethodAndRequiredPropertiesSpecified() {
	DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
	BeanDefinition beanDef = BeanDefinitionBuilder
			.genericBeanDefinition(RequiredTestBean.class)
			.setFactoryMethod("create")
			.addPropertyValue("age", "24")
			.addPropertyValue("favouriteColour", "Blue")
			.addPropertyValue("jobTitle", "Grand Poobah")
			.getBeanDefinition();
	factory.registerBeanDefinition("testBean", beanDef);
	factory.addBeanPostProcessor(new RequiredAnnotationBeanPostProcessor());
	factory.preInstantiateSingletons();
	RequiredTestBean bean = (RequiredTestBean) factory.getBean("testBean");
	assertEquals(24, bean.getAge());
	assertEquals("Blue", bean.getFavouriteColour());
}
 

@Test
public void testAbstractParentBeans() {
	DefaultListableBeanFactory parent = new DefaultListableBeanFactory();
	new XmlBeanDefinitionReader(parent).loadBeanDefinitions(PARENT_CONTEXT);
	parent.preInstantiateSingletons();
	assertTrue(parent.isSingleton("inheritedTestBeanWithoutClass"));

	// abstract beans should not match
	Map<?, ?> tbs = parent.getBeansOfType(TestBean.class);
	assertEquals(2, tbs.size());
	assertTrue(tbs.containsKey("inheritedTestBeanPrototype"));
	assertTrue(tbs.containsKey("inheritedTestBeanSingleton"));

	// abstract bean should throw exception on creation attempt
	try {
		parent.getBean("inheritedTestBeanWithoutClass");
		fail("Should have thrown BeanIsAbstractException");
	}
	catch (BeanIsAbstractException ex) {
		// expected
	}

	// non-abstract bean should work, even if it serves as parent
	assertTrue(parent.getBean("inheritedTestBeanPrototype") instanceof TestBean);
}
 

@Test
void registerAmazonWebserviceClient_withCustomRegionConfiguration_returnsBeanDefinitionWithRegionConfigured()
		throws Exception {
	// Arrange
	DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
	beanFactory.registerSingleton(
			AmazonWebserviceClientConfigurationUtils.CREDENTIALS_PROVIDER_BEAN_NAME,
			new StaticAwsCredentialsProvider());

	BeanDefinitionHolder beanDefinitionHolder = AmazonWebserviceClientConfigurationUtils
			.registerAmazonWebserviceClient(new Object(), beanFactory,
					AmazonTestWebserviceClient.class.getName(), null,
					Regions.EU_WEST_1.getName());

	// Act
	beanFactory.preInstantiateSingletons();
	AmazonTestWebserviceClient client = beanFactory.getBean(
			beanDefinitionHolder.getBeanName(), AmazonTestWebserviceClient.class);

	// Assert
	assertThat(client).isNotNull();
	assertThat(beanDefinitionHolder.getBeanName()).isEqualTo("amazonTestWebservice");
	assertThat(client.getRegion()).isEqualTo(Region.getRegion(Regions.EU_WEST_1));
}
 

@Test
public void testDependsOnCycle() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	RootBeanDefinition bd1 = new RootBeanDefinition(TestBean.class);
	bd1.setDependsOn("tb2");
	lbf.registerBeanDefinition("tb1", bd1);
	RootBeanDefinition bd2 = new RootBeanDefinition(TestBean.class);
	bd2.setDependsOn("tb1");
	lbf.registerBeanDefinition("tb2", bd2);
	try {
		lbf.preInstantiateSingletons();
		fail("Should have thrown BeanCreationException");
	}
	catch (BeanCreationException ex) {
		// expected
		assertTrue(ex.getMessage().contains("Circular"));
		assertTrue(ex.getMessage().contains("'tb2'"));
		assertTrue(ex.getMessage().contains("'tb1'"));
	}
}
 

@Test
public void testFactoryMethodWithDifferentReturnType() {
	DefaultListableBeanFactory xbf = new DefaultListableBeanFactory();
	XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(xbf);
	reader.loadBeanDefinitions(new ClassPathResource("factory-methods.xml", getClass()));

	// Check that listInstance is not considered a bean of type FactoryMethods.
	assertTrue(List.class.isAssignableFrom(xbf.getType("listInstance")));
	String[] names = xbf.getBeanNamesForType(FactoryMethods.class);
	assertTrue(!Arrays.asList(names).contains("listInstance"));
	names = xbf.getBeanNamesForType(List.class);
	assertTrue(Arrays.asList(names).contains("listInstance"));

	xbf.preInstantiateSingletons();
	assertTrue(List.class.isAssignableFrom(xbf.getType("listInstance")));
	names = xbf.getBeanNamesForType(FactoryMethods.class);
	assertTrue(!Arrays.asList(names).contains("listInstance"));
	names = xbf.getBeanNamesForType(List.class);
	assertTrue(Arrays.asList(names).contains("listInstance"));
	List<?> list = (List<?>) xbf.getBean("listInstance");
	assertEquals(Collections.EMPTY_LIST, list);
}
 

@Test
public void byTypeAutowireWithPrimaryOverridingParentFactory() throws Exception {
	CountingFactory.reset();
	DefaultListableBeanFactory parent = getBeanFactory("autowire-with-exclusion.xml");
	parent.preInstantiateSingletons();
	DefaultListableBeanFactory child = new DefaultListableBeanFactory(parent);
	RootBeanDefinition robDef = new RootBeanDefinition(TestBean.class);
	robDef.setAutowireMode(RootBeanDefinition.AUTOWIRE_BY_TYPE);
	robDef.getPropertyValues().add("spouse", new RuntimeBeanReference("sally"));
	child.registerBeanDefinition("rob2", robDef);
	RootBeanDefinition propsDef = new RootBeanDefinition(PropertiesFactoryBean.class);
	propsDef.getPropertyValues().add("properties", "name=props3");
	propsDef.setPrimary(true);
	child.registerBeanDefinition("props3", propsDef);
	TestBean rob = (TestBean) child.getBean("rob2");
	assertEquals("props3", rob.getSomeProperties().getProperty("name"));
	assertEquals(1, CountingFactory.getFactoryBeanInstanceCount());
}
 

@Test
public void testWithCustomAnnotation() {
	try {
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		BeanDefinition beanDef = BeanDefinitionBuilder
			.genericBeanDefinition(RequiredTestBean.class)
			.getBeanDefinition();
		factory.registerBeanDefinition("testBean", beanDef);
		RequiredAnnotationBeanPostProcessor rabpp = new RequiredAnnotationBeanPostProcessor();
		rabpp.setRequiredAnnotationType(MyRequired.class);
		factory.addBeanPostProcessor(rabpp);
		factory.preInstantiateSingletons();
		fail("Should have thrown BeanCreationException");
	}
	catch (BeanCreationException ex) {
		String message = ex.getCause().getMessage();
		assertTrue(message.contains("Property"));
		assertTrue(message.contains("name"));
		assertTrue(message.contains("testBean"));
	}
}
 

@Test
public void testCircularReferenceThroughAutowiring() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	RootBeanDefinition bd = new RootBeanDefinition(ConstructorDependencyBean.class);
	bd.setAutowireMode(RootBeanDefinition.AUTOWIRE_CONSTRUCTOR);
	lbf.registerBeanDefinition("test", bd);
	try {
		lbf.preInstantiateSingletons();
		fail("Should have thrown UnsatisfiedDependencyException");
	}
	catch (UnsatisfiedDependencyException expected) {
	}
}
 

@Test
public void byTypeAutowireWithExclusionInParentFactory() throws Exception {
	CountingFactory.reset();
	DefaultListableBeanFactory parent = getBeanFactory("autowire-with-exclusion.xml");
	parent.preInstantiateSingletons();
	DefaultListableBeanFactory child = new DefaultListableBeanFactory(parent);
	RootBeanDefinition robDef = new RootBeanDefinition(TestBean.class);
	robDef.setAutowireMode(RootBeanDefinition.AUTOWIRE_BY_TYPE);
	robDef.getPropertyValues().add("spouse", new RuntimeBeanReference("sally"));
	child.registerBeanDefinition("rob2", robDef);
	TestBean rob = (TestBean) child.getBean("rob2");
	assertEquals("props1", rob.getSomeProperties().getProperty("name"));
	assertEquals(1, CountingFactory.getFactoryBeanInstanceCount());
}
 

@Test
public void testBeanDefinitionRemoval() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	lbf.setAllowBeanDefinitionOverriding(false);
	lbf.registerBeanDefinition("test", new RootBeanDefinition(TestBean.class));
	lbf.registerAlias("test", "test2");
	lbf.preInstantiateSingletons();
	lbf.removeBeanDefinition("test");
	lbf.removeAlias("test2");
	lbf.registerBeanDefinition("test", new RootBeanDefinition(NestedTestBean.class));
	lbf.registerAlias("test", "test2");
	assertTrue(lbf.getBean("test") instanceof NestedTestBean);
	assertTrue(lbf.getBean("test2") instanceof NestedTestBean);
}
 

@Test
public void testRegisterExistingSingletonWithNameOverriding() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	Properties p = new Properties();
	p.setProperty("test.(class)", TestBean.class.getName());
	p.setProperty("test.name", "Tony");
	p.setProperty("test.age", "48");
	p.setProperty("test.spouse(ref)", "singletonObject");
	(new PropertiesBeanDefinitionReader(lbf)).registerBeanDefinitions(p);
	lbf.registerBeanDefinition("singletonObject", new RootBeanDefinition(PropertiesFactoryBean.class));
	Object singletonObject = new TestBean();
	lbf.registerSingleton("singletonObject", singletonObject);
	lbf.preInstantiateSingletons();

	assertTrue(lbf.isSingleton("singletonObject"));
	assertEquals(TestBean.class, lbf.getType("singletonObject"));
	TestBean test = (TestBean) lbf.getBean("test");
	assertEquals(singletonObject, lbf.getBean("singletonObject"));
	assertEquals(singletonObject, test.getSpouse());

	Map<?, ?>  beansOfType = lbf.getBeansOfType(TestBean.class, false, true);
	assertEquals(2, beansOfType.size());
	assertTrue(beansOfType.containsValue(test));
	assertTrue(beansOfType.containsValue(singletonObject));

	beansOfType = lbf.getBeansOfType(null, false, true);

	Iterator<String> beanNames = lbf.getBeanNamesIterator();
	assertEquals("test", beanNames.next());
	assertEquals("singletonObject", beanNames.next());
	assertFalse(beanNames.hasNext());
	assertEquals(2, beansOfType.size());

	assertTrue(lbf.containsSingleton("test"));
	assertTrue(lbf.containsSingleton("singletonObject"));
	assertTrue(lbf.containsBeanDefinition("test"));
	assertTrue(lbf.containsBeanDefinition("singletonObject"));
}
 

@Test
public void testDestroyMethodOnInnerBeanAsPrototype() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	RootBeanDefinition innerBd = new RootBeanDefinition(BeanWithDestroyMethod.class);
	innerBd.setScope(RootBeanDefinition.SCOPE_PROTOTYPE);
	innerBd.setDestroyMethodName("close");
	RootBeanDefinition bd = new RootBeanDefinition(BeanWithDestroyMethod.class);
	bd.setDestroyMethodName("close");
	bd.getPropertyValues().add("inner", innerBd);
	lbf.registerBeanDefinition("test", bd);
	BeanWithDestroyMethod.closeCount = 0;
	lbf.preInstantiateSingletons();
	lbf.destroySingletons();
	assertEquals("Destroy methods invoked", 1, BeanWithDestroyMethod.closeCount);
}
 

@Test
public void testSmartInitFactory() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	lbf.registerBeanDefinition("test", new RootBeanDefinition(EagerInitFactory.class));
	lbf.preInstantiateSingletons();
	EagerInitFactory factory = (EagerInitFactory) lbf.getBean("&test");
	assertTrue(factory.initialized);
}
 

@Test
public void testUnreferencedSingletonWasInstantiated() {
	KnowsIfInstantiated.clearInstantiationRecord();
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	Properties p = new Properties();
	p.setProperty("x1.(class)", KnowsIfInstantiated.class.getName());
	assertTrue("singleton not instantiated", !KnowsIfInstantiated.wasInstantiated());
	(new PropertiesBeanDefinitionReader(lbf)).registerBeanDefinitions(p);
	lbf.preInstantiateSingletons();
	assertTrue("singleton was instantiated", KnowsIfInstantiated.wasInstantiated());
}
 

@Test
public void ignoreDefaultLifecycleMethods() throws Exception {
	DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
	new XmlBeanDefinitionReader(bf).loadBeanDefinitions(new ClassPathResource(
			"ignoreDefaultLifecycleMethods.xml", getClass()));
	bf.preInstantiateSingletons();
	bf.destroySingletons();
}
 

@Test
public void testDestroyMethodOnInnerBean() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	RootBeanDefinition innerBd = new RootBeanDefinition(BeanWithDestroyMethod.class);
	innerBd.setDestroyMethodName("close");
	RootBeanDefinition bd = new RootBeanDefinition(BeanWithDestroyMethod.class);
	bd.setDestroyMethodName("close");
	bd.getPropertyValues().add("inner", innerBd);
	lbf.registerBeanDefinition("test", bd);
	BeanWithDestroyMethod.closeCount = 0;
	lbf.preInstantiateSingletons();
	lbf.destroySingletons();
	assertEquals("Destroy methods invoked", 2, BeanWithDestroyMethod.closeCount);
}
 

@Test
public void testAvoidCircularReferenceThroughAutowiring() {
	DefaultListableBeanFactory lbf = new DefaultListableBeanFactory();
	RootBeanDefinition bd = new RootBeanDefinition(ConstructorDependencyFactoryBean.class);
	bd.setAutowireMode(RootBeanDefinition.AUTOWIRE_CONSTRUCTOR);
	lbf.registerBeanDefinition("test", bd);
	RootBeanDefinition bd2 = new RootBeanDefinition(String.class);
	bd2.setAutowireMode(RootBeanDefinition.AUTOWIRE_CONSTRUCTOR);
	lbf.registerBeanDefinition("string", bd2);
	lbf.preInstantiateSingletons();
}
 

public static void main(String[] args) throws InterruptedException {
    DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
    // 添加 BeanPostProcessor 实现 MyInstantiationAwareBeanPostProcessor
    beanFactory.addBeanPostProcessor(new MyInstantiationAwareBeanPostProcessor());
    // 添加 MyDestructionAwareBeanPostProcessor 执行销毁前回调
    beanFactory.addBeanPostProcessor(new MyDestructionAwareBeanPostProcessor());
    // 添加 CommonAnnotationBeanPostProcessor 解决 @PostConstruct @PreDestroy
    beanFactory.addBeanPostProcessor(new CommonAnnotationBeanPostProcessor());

    XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory);
    String[] locations = {"META-INF/dependency-lookup-context.xml", "META-INF/bean-constructor-dependency-injection.xml"};
    int beanNumbers = beanDefinitionReader.loadBeanDefinitions(locations);
    System.out.println("已加载 BeanDefinition 数量：" + beanNumbers);
    // 显示地执行 preInstantiateSingletons()
    // SmartInitializingSingleton 通常在 Spring ApplicationContext 场景使用
    // preInstantiateSingletons 将已注册的 BeanDefinition 初始化成 Spring Bean
    beanFactory.preInstantiateSingletons();

    // 通过 Bean Id 和类型进行依赖查找
    User user = beanFactory.getBean("user", User.class);
    System.out.println(user);

    User superUser = beanFactory.getBean("superUser", User.class);
    System.out.println(superUser);

    // 构造器注入按照类型注入，resolveDependency
    UserHolder userHolder = beanFactory.getBean("userHolder", UserHolder.class);

    System.out.println(userHolder);

    // 执行 Bean 销毁（容器内）
    beanFactory.destroyBean("userHolder", userHolder);
    // Bean 销毁并不意味着 Bean 垃圾回收了
    System.out.println(userHolder);

    // 销毁 BeanFactory 中的单例 Bean
    beanFactory.destroySingletons();
    // 强制 GC
    System.gc();
    // 等待一段时间
    Thread.sleep(1000L);
    // 强制 GC
    System.gc();
}
 

@Test
public void testCollectionsReferredToAsRefLocals() throws Exception {
	DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
	new XmlBeanDefinitionReader(factory).loadBeanDefinitions(COLLECTIONS_XSD_CONTEXT);
	factory.preInstantiateSingletons();
}