myconfig.name=test
myconfig.age=22
myconfig.desc=這是我的測試描述

@Component
@ConfigurationProperties(prefix = "myconfig")
public class MyConfig {
private String name;
private Integer age;
private String desc;
  //get/set 略
  @Override
public String toString() {
	return "MyConfig [name=" + name + ", age=" + age + ", desc=" + desc + "]";
}
}

public static void main(String[] args) throws Exception {
	SpringApplication springApplication = new SpringApplication(Application.class);
	// 非web環(huán)境
	springApplication.setWebEnvironment(false);
	ConfigurableApplicationContext application = springApplication.run(args);

	MyConfig config = application.getBean(MyConfig.class);
	log.info(config.toString());
	application.close();
}

com.cml.chat.lesson.lesson3.Application - MyConfig [name=test, age=22, desc=這是我的測試描述]

public class ConfigurationPropertiesBindingPostProcessor implements BeanPostProcessor,
	BeanFactoryAware, EnvironmentAware, ApplicationContextAware, InitializingBean,
	DisposableBean, ApplicationListener<ContextRefreshedEvent>, PriorityOrdered 

@Override
public Object postProcessBeforeInitialization(Object bean, String beanName)
		throws BeansException {
	//直接通過查找添加了ConfigurationProperties注解的的類
	ConfigurationProperties annotation = AnnotationUtils
			.findAnnotation(bean.getClass(), ConfigurationProperties.class);
	if (annotation != null) {
		postProcessBeforeInitialization(bean, beanName, annotation);
	}
	//查找使用工廠bean中是否有ConfigurationProperties注解
	annotation = this.beans.findFactoryAnnotation(beanName,
			ConfigurationProperties.class);
	if (annotation != null) {
		postProcessBeforeInitialization(bean, beanName, annotation);
	}
	return bean;
}

private void postProcessBeforeInitialization(Object bean, String beanName,
		ConfigurationProperties annotation) {
	Object target = bean;
	PropertiesConfigurationFactory<Object> factory = new PropertiesConfigurationFactory<Object>(
			target);
	factory.setPropertySources(this.propertySources);
	factory.setValidator(determineValidator(bean));
	// If no explicit conversion service is provided we add one so that (at least)
	// comma-separated arrays of convertibles can be bound automatically
	factory.setConversionService(this.conversionService == null
			? getDefaultConversionService() : this.conversionService);
	if (annotation != null) {
		factory.setIgnoreInvalidFields(annotation.ignoreInvalidFields());
		factory.setIgnoreUnknownFields(annotation.ignoreUnknownFields());
		factory.setExceptionIfInvalid(annotation.exceptionIfInvalid());
		factory.setIgnoreNestedProperties(annotation.ignoreNestedProperties());
		if (StringUtils.hasLength(annotation.prefix())) {
			factory.setTargetName(annotation.prefix());
		}
	}
	try {
		factory.bindPropertiesToTarget();
	}
	catch (Exception ex) {
		String targetClass = ClassUtils.getShortName(target.getClass());
		throw new BeanCreationException(beanName, "Could not bind properties to "
				+ targetClass + " (" + getAnnotationDetails(annotation) + ")", ex);
	}
}

public class ConfigurationBeanFactoryMetaData implements BeanFactoryPostProcessor {

private ConfigurableListableBeanFactory beanFactory;

private Map<String, MetaData> beans = new HashMap<String, MetaData>();

@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory)
		throws BeansException {
	this.beanFactory = beanFactory;
 //迭代所有的bean定義，找出那些是工廠bean的對象添加到beans中
	for (String name : beanFactory.getBeanDefinitionNames()) {
		BeanDefinition definition = beanFactory.getBeanDefinition(name);
		String method = definition.getFactoryMethodName();
		String bean = definition.getFactoryBeanName();
		if (method != null && bean != null) {
			this.beans.put(name, new MetaData(bean, method));
		}
	}
}

public <A extends Annotation> Map<String, Object> getBeansWithFactoryAnnotation(
		Class<A> type) {
	Map<String, Object> result = new HashMap<String, Object>();
	for (String name : this.beans.keySet()) {
		if (findFactoryAnnotation(name, type) != null) {
			result.put(name, this.beanFactory.getBean(name));
		}
	}
	return result;
}

public <A extends Annotation> A findFactoryAnnotation(String beanName,
		Class<A> type) {
	Method method = findFactoryMethod(beanName);
	return (method == null ? null : AnnotationUtils.findAnnotation(method, type));
}

//略...
	
private static class MetaData {
	private String bean;
	private String method;
  //構造方法和其他方法略...
}

}

private void postProcessBeforeInitialization(Object bean, String beanName,
		ConfigurationProperties annotation) {
	Object target = bean;
	PropertiesConfigurationFactory<Object> factory = new PropertiesConfigurationFactory<Object>(
			target);
	//重點，這里設置數(shù)據(jù)來源
	factory.setPropertySources(this.propertySources);
	factory.setValidator(determineValidator(bean));
	//設置轉換器
	factory.setConversionService(this.conversionService == null
			? getDefaultConversionService() : this.conversionService);
	if (annotation != null) {
	//將annotation中配置的屬性配置到factory中
	}
	try {
	  //這里是核心，綁定屬性值到對象中
		factory.bindPropertiesToTarget();
	}
	catch (Exception ex) {
	//拋出異常
	}
}

private void doBindPropertiesToTarget() throws BindException {
	RelaxedDataBinder dataBinder 
  //略...
  //1、獲取bean中所有的屬性名稱
  Set<String> names = getNames(relaxedTargetNames);
  //2、將屬性名稱和前綴轉換為配置文件的key值
  PropertyValues propertyValues = getPropertySourcesPropertyValues(names,relaxedTargetNames);
  //3、通過上面兩個步驟找到的屬性從配置文件中獲取數(shù)據(jù)通過反射注入到bean中
	dataBinder.bind(propertyValues);
	//數(shù)據(jù)校驗
	if (this.validator != null) {
		dataBinder.validate();
	}
	//判斷數(shù)據(jù)綁定過程中是否有錯誤
	checkForBindingErrors(dataBinder);
}

public void bind(PropertyValues pvs) {
	MutablePropertyValues mpvs = (pvs instanceof MutablePropertyValues) ?
			(MutablePropertyValues) pvs : new MutablePropertyValues(pvs);
	doBind(mpvs);
}
protected void doBind(MutablePropertyValues mpvs) {
	checkAllowedFields(mpvs);
	checkRequiredFields(mpvs);
	//進行賦值
	applyPropertyValues(mpvs);
}
protected void applyPropertyValues(MutablePropertyValues mpvs) {
	try {
		// Bind request parameters onto target object.
		getPropertyAccessor().setPropertyValues(mpvs, isIgnoreUnknownFields(), isIgnoreInvalidFields());
	}
	catch (PropertyBatchUpdateException ex) {
		// Use bind error processor to create FieldErrors.
		for (PropertyAccessException pae : ex.getPropertyAccessExceptions()) {
			getBindingErrorProcessor().processPropertyAccessException(pae, getInternalBindingResult());
		}
	}
}