前言

本文不讲解源码，仅记录加载过程中的一部分。看本文需要先知道spring对BeanDefinition的处理，对bean的实例化。

单元测试和配置

public class Config {

}

public class ContextLoadTest {
    private ApplicationContext ctx = null;
    
    @Before
    public void setUp() {
        ctx = new AnnotationConfigApplicationContext(Config.class);
    }
    
    
    @Test
    public void testContextLoads() {
        
    }
    
}

BeanDefinition的加载堆栈记载

org.eclipse.jdt.internal.junit.runner.RemoteTestRunner at localhost:58478   
    Thread [main] (Suspended (breakpoint at line 846 in DefaultListableBeanFactory))    
        owns: ConcurrentHashMap<K,V>  (id=111)  
        owns: Object  (id=96)   
        DefaultListableBeanFactory.registerBeanDefinition(String, BeanDefinition) line: 846 
        ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(BeanMethod) line: 266   
        ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClass, ConfigurationClassBeanDefinitionReader$TrackedConditionEvaluator) line: 140 
        ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(Set<ConfigurationClass>) line: 116   
        ConfigurationClassPostProcessor.processConfigBeanDefinitions(BeanDefinitionRegistry) line: 320  
        ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(BeanDefinitionRegistry) line: 228 
        PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(Collection<BeanDefinitionRegistryPostProcessor>, BeanDefinitionRegistry) line: 272 
        PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory, List<BeanFactoryPostProcessor>) line: 92 
        AnnotationConfigApplicationContext(AbstractApplicationContext).invokeBeanFactoryPostProcessors(ConfigurableListableBeanFactory) line: 687   
        AnnotationConfigApplicationContext(AbstractApplicationContext).refresh() line: 525  
        AnnotationConfigApplicationContext.<init>(Class<?>...) line: 84 
        BeanOverrideTest.setUp() line: 16   
        NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]  
        NativeMethodAccessorImpl.invoke(Object, Object[]) line: 62  
        DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 43  
        Method.invoke(Object, Object...) line: 498  
        FrameworkMethod$1.runReflectiveCall() line: 50  
        FrameworkMethod$1(ReflectiveCallable).run() line: 12    
        FrameworkMethod.invokeExplosively(Object, Object...) line: 47   
        RunBefores.evaluate() line: 24  
        BlockJUnit4ClassRunner(ParentRunner<T>).runLeaf(Statement, Description, RunNotifier) line: 325  
        BlockJUnit4ClassRunner.runChild(FrameworkMethod, RunNotifier) line: 78  
        BlockJUnit4ClassRunner.runChild(Object, RunNotifier) line: 57   
        ParentRunner$3.run() line: 290  
        ParentRunner$1.schedule(Runnable) line: 71  
        BlockJUnit4ClassRunner(ParentRunner<T>).runChildren(RunNotifier) line: 288  
        ParentRunner<T>.access$000(ParentRunner, RunNotifier) line: 58  
        ParentRunner$2.evaluate() line: 268 
        BlockJUnit4ClassRunner(ParentRunner<T>).run(RunNotifier) line: 363  
        JUnit4TestReference.run(TestExecution) line: 86 
        TestExecution.run(ITestReference[]) line: 38    
        RemoteTestRunner.runTests(String[], String, TestExecution) line: 538    
        RemoteTestRunner.runTests(TestExecution) line: 760  
        RemoteTestRunner.run() line: 460    
        RemoteTestRunner.main(String[]) line: 206   
    Thread [ReaderThread] (Running)

值得留意的是：

ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(Set<ConfigurationClass>) line: 116

这里就是把BeanDefinition从configuration class加载进来的过程，类似解析xml。

BeanDefinition的注册：

org.springframework.beans.factory.support.DefaultListableBeanFactory.registerBeanDefinition(String, BeanDefinition)