Introduction: From Spring2.0 future releases began, Spring introduced a configuration-based annotation (Annotation) method, annotations are a new feature introduced in JDK1.5, Bean to simplify configuration, some cases can replace the XML configuration file . Annotations can greatly simplify the configuration, speed up development, but can not completely replace the XML configuration. XML is more flexible, and the development of relatively mature, this configuration for most developers familiar with Spring; annotation mode is very simple to use, is still in the development stage, XML configuration files and annotations (Annotation) can be used in conjunction with each other.
Spring IOC container annotation for class level annotations and classes inside the two treatment strategies:
(1) the class level annotation: such as @ Component, @ Repository, @ Controller , @ Service and JavaEE6 of @ManagedBean and @Named notes are class-level annotation is added to the above classes, Spring container according to the read scan annotation filtering rules define classes Bean annotation, and register it to the Spring IOC container;
(2) inside the annotation class: as @ Autowire, @ Value, @Resource WebService and EJB and related notes, are added to the inside of the field or method in class class internal annotation, SpringIOC annotated parse inside the container by Bean Bean annotation post processor.
Next will be based on these two treatment strategies, analyze Spring annotation processing the relevant source code.
1.AnnotationConfigApplicationContext to comment Bean initialization
Spring, management notes the definition of Bean container has two: AnnotationConfigApplicationContext and AnnotationConfigWebApplicationContex.
These two classes are specialized processing container arranged Spring annotation mode, as directly dependent on the annotation IOC container vessel configuration information sources.
AnnotationConfigWebApplicationContext is a web version of AnnotationConfigApplicationContext, there is little difference between the two usage and handling of annotations.
AnnotationConfigApplicationContext source code as follows:
public class AnnotationConfigApplicationContext extends GenericApplicationContext implements AnnotationConfigRegistry {
//保存一个读取注解Bean定义的读取器，并将其设置到容器中
private final AnnotatedBeanDefinitionReader reader;
//保存一个扫描指定类路径中注解Bean定义的扫描器，并将其设置到容器中
private final ClassPathBeanDefinitionScanner scanner;
//默认构造函数，初始化一个空容器，容器不包含任何 Bean 信息，需要在稍后通过调用其register()方法注册配置类，并调用refresh()方法刷新容器，触发容器对注解Bean的载入、解析和注册过程
public AnnotationConfigApplicationContext() {
this.reader = new AnnotatedBeanDefinitionReader(this);
this.scanner = new ClassPathBeanDefinitionScanner(this);
}
public AnnotationConfigApplicationContext(DefaultListableBeanFactory beanFactory) {
super(beanFactory);
this.reader = new AnnotatedBeanDefinitionReader(this);
this.scanner = new ClassPathBeanDefinitionScanner(this);
}
//最常用的构造函数，通过将涉及到的配置类传递给该构造函数，以实现将相应配置类中的Bean自动注册到容器中
public AnnotationConfigApplicationContext(Class<?>... annotatedClasses) {
this();
register(annotatedClasses);
refresh();
}
//该构造函数会自动扫描以给定的包及其子包下的所有类，并自动识别所有的Spring Bean，将其注册到容器中
public AnnotationConfigApplicationContext(String... basePackages) {
this();
scan(basePackages);
refresh();
}
@Override
public void setEnvironment(ConfigurableEnvironment environment) {
super.setEnvironment(environment);
this.reader.setEnvironment(environment);
this.scanner.setEnvironment(environment);
}
//为容器的注解Bean读取器和注解Bean扫描器设置Bean名称产生器
public void setBeanNameGenerator(BeanNameGenerator beanNameGenerator) {
this.reader.setBeanNameGenerator(beanNameGenerator);
this.scanner.setBeanNameGenerator(beanNameGenerator);
getBeanFactory().registerSingleton(
AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR, beanNameGenerator);
}
//为容器的注解Bean读取器和注解Bean扫描器设置作用范围元信息解析器
public void setScopeMetadataResolver(ScopeMetadataResolver scopeMetadataResolver) {
this.reader.setScopeMetadataResolver(scopeMetadataResolver);
this.scanner.setScopeMetadataResolver(scopeMetadataResolver);
}
//为容器注册一个要被处理的注解Bean，新注册的Bean，必须手动调用容器的refresh()方法刷新容器，触发容器对新注册的Bean的处理
public void register(Class<?>... annotatedClasses) {
Assert.notEmpty(annotatedClasses, "At least one annotated class must be specified");
this.reader.register(annotatedClasses);
}
//扫描指定包路径及其子包下的注解类，为了使新添加的类被处理，必须手动调用refresh()方法刷新容器
public void scan(String... basePackages) {
Assert.notEmpty(basePackages, "At least one base package must be specified");
this.scanner.scan(basePackages);
}
...
}Spring annotation analysis shows that treatment is divided into two ways:
(1) directly registered to comment Bean container: You can register at initialization container, you can also call registration methods after the container is created manually register the container, and then manually refresh container such that the container to be annotated Bean registration process;
all classes in (2) by scanning the specified package and its sub-packets: Specifies the path to be automatically scanned annotations initialization container, if the container after the given path dynamically create Add a comment Bean, you will need to manually call the container scanning method, and then manually refresh the container such that the container of the registered Bean for processing.
2.AnnotationConfigApplicationContext registered notes Bean
When creating annotation processing vessel, if the incoming parameter is the initial specific comments Bean define a class, read and comment vessel registration.
By invoking the register method AnnotationConfigApplicationContext annotation reader AnnotatedBeanDefinitionReader Bean definitions registered to the vessel designated Bean annotation, annotation Bean definitions reader annotations Bean source register as the vessel:
//注册多个注解Bean定义类
public void register(Class<?>... annotatedClasses) {
for (Class<?> annotatedClass : annotatedClasses) {
registerBean(annotatedClass);
}
}
//注册一个注解Bean定义类
public void registerBean(Class<?> annotatedClass) {
doRegisterBean(annotatedClass, null, null, null);
}
//Bean定义读取器向容器注册注解Bean定义类
@SuppressWarnings("unchecked")
public void registerBean(Class<?> annotatedClass, String name, Class<? extends Annotation>... qualifiers) {
doRegisterBean(annotatedClass, null, name, qualifiers);
}
//Bean定义读取器向容器注册注解Bean定义类
<T> void doRegisterBean(Class<T> annotatedClass, @Nullable Supplier<T> instanceSupplier, @Nullable String name,
@Nullable Class<? extends Annotation>[] qualifiers, BeanDefinitionCustomizer... definitionCustomizers) {
//根据指定的注解Bean定义类，创建Spring容器中对注解Bean的封装的数据结构
AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(annotatedClass);
if (this.conditionEvaluator.shouldSkip(abd.getMetadata())) {
return;
}
abd.setInstanceSupplier(instanceSupplier);
//解析注解Bean定义的作用域，若@Scope("prototype")，则Bean为原型类型；若@Scope("singleton")，则Bean为单态类型
ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(abd);
//为注解Bean定义设置作用域
abd.setScope(scopeMetadata.getScopeName());
//为注解Bean定义生成Bean名称
String beanName = (name != null ? name : this.beanNameGenerator.generateBeanName(abd, this.registry));
//处理注解Bean定义中的通用注解
AnnotationConfigUtils.processCommonDefinitionAnnotations(abd);
//如果在向容器注册注解Bean定义时，使用了额外的限定符注解，则解析限定符注解。
//主要是配置的关于autowiring自动依赖注入装配的限定条件，即@Qualifier注解
//Spring自动依赖注入装配默认是按类型装配，如果使用@Qualifier则按名称
if (qualifiers != null) {
for (Class<? extends Annotation> qualifier : qualifiers) {
//如果配置了@Primary注解，设置该Bean为autowiring自动依赖注入装配时的首选
if (Primary.class == qualifier) {
abd.setPrimary(true);
}
//如果配置了@Lazy注解，则设置该Bean为延迟初始化，如果没有配置，则该Bean为预实例化
else if (Lazy.class == qualifier) {
abd.setLazyInit(true);
}
//如果使用了除@Primary和@Lazy以外的其他注解，则为该Bean添加一个autowiring自动依赖注入装配限定符，该Bean在进autowiring自动依赖注入装配时，根据名称装配限定符指定的Bean
else {
abd.addQualifier(new AutowireCandidateQualifier(qualifier));
}
}
}
for (BeanDefinitionCustomizer customizer : definitionCustomizers) {
customizer.customize(abd);
}
//创建一个指定Bean名称的Bean定义对象，封装注解Bean定义类数据
BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(abd, beanName);
//根据注解Bean定义类中配置的作用域，创建相应的代理对象
definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
//向IOC容器注册注解Bean类定义对象
BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, this.registry);
}As can be seen from the source, the basic steps annotations register Bean class definition:
A requires the use of annotation metadata annotation parser configured on Bean scope;.
B AnnotationConfigUtils processing method using processCommonDefinitionAnnotations annotation Bean class definitions common annotation. ; C
applyScopedProxyMode created using a method for the proxy object AnnotationConfigUtils scope;.
. D through the container register Bean BeanDefinitionReaderUtils.
(1) AnnotationScopeMetadataResolver parse metadata scope
AnnotationScopeMetadataResolver annotated by resolveScopeMetadata analytically Bean scope defined class meta-information, i.e., registration determination Bean native type (the prototype) or singlet (Singleton) type, the following source code:
//解析注解Bean定义类中的作用域元信息
@Override
public ScopeMetadata resolveScopeMetadata(BeanDefinition definition) {
ScopeMetadata metadata = new ScopeMetadata();
if (definition instanceof AnnotatedBeanDefinition) {
AnnotatedBeanDefinition annDef = (AnnotatedBeanDefinition) definition;
//从注解Bean定义类的属性中查找属性为”Scope”的值，即@Scope注解的值
//annDef.getMetadata().getAnnotationAttributes方法将Bean中所有的注解和注解的值存放在一个map集合中
AnnotationAttributes attributes = AnnotationConfigUtils.attributesFor(
annDef.getMetadata(), this.scopeAnnotationType);
//将获取到的@Scope注解的值设置到要返回的对象中
if (attributes != null) {
metadata.setScopeName(attributes.getString("value"));
//获取@Scope注解中的proxyMode属性值，在创建代理对象时会用到
ScopedProxyMode proxyMode = attributes.getEnum("proxyMode");
//如果@Scope的proxyMode属性为DEFAULT或者NO
if (proxyMode == ScopedProxyMode.DEFAULT) {
//设置proxyMode为NO
proxyMode = this.defaultProxyMode;
}
//为返回的元数据设置proxyMode
metadata.setScopedProxyMode(proxyMode);
}
}
//返回解析的作用域元信息对象
return metadata;
}Code annDef.getMetadata (). GetAnnotationAttributes the object is to get the value of the specified types of notes.
(2) AnnotationConfigUtils general comment annotation process defined class Bean
AnnotationConfigUtils class processCommonDefinitionAnnotations Bean before registering the container, is first defined for annotation Bean class Spring general annotation for processing source code as follows:
//处理Bean定义中通用注解
static void processCommonDefinitionAnnotations(AnnotatedBeanDefinition abd, AnnotatedTypeMetadata metadata) {
AnnotationAttributes lazy = attributesFor(metadata, Lazy.class);
//如果Bean定义中有@Lazy注解，则将该Bean预实例化属性设置为@lazy注解的值
if (lazy != null) {
abd.setLazyInit(lazy.getBoolean("value"));
}
else if (abd.getMetadata() != metadata) {
lazy = attributesFor(abd.getMetadata(), Lazy.class);
if (lazy != null) {
abd.setLazyInit(lazy.getBoolean("value"));
}
}
//如果Bean定义中有@Primary注解，则为该Bean设置为autowiring自动依赖注入装配的首选对象
if (metadata.isAnnotated(Primary.class.getName())) {
abd.setPrimary(true);
}
//如果Bean定义中有@DependsOn注解，则为该Bean设置所依赖的Bean名称，容器将确保在实例化该Bean之前首先实例化所依赖的Bean
AnnotationAttributes dependsOn = attributesFor(metadata, DependsOn.class);
if (dependsOn != null) {
abd.setDependsOn(dependsOn.getStringArray("value"));
}
if (abd instanceof AbstractBeanDefinition) {
AbstractBeanDefinition absBd = (AbstractBeanDefinition) abd;
AnnotationAttributes role = attributesFor(metadata, Role.class);
if (role != null) {
absBd.setRole(role.getNumber("value").intValue());
}
AnnotationAttributes description = attributesFor(metadata, Description.class);
if (description != null) {
absBd.setDescription(description.getString("value"));
}
}
}(3) AnnotationConfigUtils proxy policy
Method according applyScopedProxyMode AnnotationConfigUtils class value scope @Scope annotation annotation configured Bean class definitions as the corresponding proxy mode defined Bean applications, mainly in the Spring Aspect Oriented Programming (AOP) is used, the following source code:
//根据作用域为Bean应用引用的代码模式
static BeanDefinitionHolder applyScopedProxyMode(
ScopeMetadata metadata, BeanDefinitionHolder definition, BeanDefinitionRegistry registry) {
//获取注解Bean定义类中@Scope注解的proxyMode属性值
ScopedProxyMode scopedProxyMode = metadata.getScopedProxyMode();
//如果配置的@Scope注解的proxyMode属性值为NO，则不应用代理模式
if (scopedProxyMode.equals(ScopedProxyMode.NO)) {
return definition;
}
//获取配置的@Scope注解的proxyMode属性值，如果为TARGET_CLASS，则返回true，如果为INTERFACES，则返回false
boolean proxyTargetClass = scopedProxyMode.equals(ScopedProxyMode.TARGET_CLASS);
//为注册的Bean创建相应模式的代理对象
return ScopedProxyCreator.createScopedProxy(definition, registry, proxyTargetClass);
}3.AnnotationConfigApplicationContext scan the specified comment Bean under the package and its subpackages
When creating annotation processing vessel, if the parameter is passed in the initial package annotation to define classes Bean is located, the container will be scanned notes given to the package and its sub packages will be scanned to comment Bean definition of loaded and registered.
(1) ClassPathBeanDefinitionScanner scanning given package and its sub-packets
AnnotationConfigApplicationContext scan all the classes in a given package and its subpackages Bean class path defined by calling the scanner ClassPathBeanDefinitionScanner, major source as follows:
public class ClassPathBeanDefinitionScanner extends ClassPathScanningCandidateComponentProvider {
//创建一个类路径Bean定义扫描器
public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry) {
this(registry, true);
}
//为容器创建一个类路径Bean定义扫描器，并指定是否使用默认的扫描过滤规则。
//即Spring默认扫描配置：@Component、@Repository、@Service、@Controller注解的Bean，同时也支持JavaEE6的@ManagedBean和JSR-330的@Named注解
public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry, boolean useDefaultFilters) {
this(registry, useDefaultFilters, getOrCreateEnvironment(registry));
}
public ClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry, boolean useDefaultFilters,
Environment environment, @Nullable ResourceLoader resourceLoader) {
Assert.notNull(registry, "BeanDefinitionRegistry must not be null");
//为容器设置加载Bean定义的注册器
this.registry = registry;
if (useDefaultFilters) {
registerDefaultFilters();
}
setEnvironment(environment);
//为容器设置资源加载器
setResourceLoader(resourceLoader);
}
//调用类路径Bean定义扫描器入口方法
public int scan(String... basePackages) {
//获取容器中已经注册的Bean个数
int beanCountAtScanStart = this.registry.getBeanDefinitionCount();
//启动扫描器扫描给定包
doScan(basePackages);
//注册注解配置(Annotation config)处理器
if (this.includeAnnotationConfig) {
AnnotationConfigUtils.registerAnnotationConfigProcessors(this.registry);
}
//返回注册的Bean个数
return (this.registry.getBeanDefinitionCount() - beanCountAtScanStart);
}
//类路径Bean定义扫描器扫描给定包及其子包
protected Set<BeanDefinitionHolder> doScan(String... basePackages) {
Assert.notEmpty(basePackages, "At least one base package must be specified");
//创建一个集合，存放扫描到Bean定义的封装类
Set<BeanDefinitionHolder> beanDefinitions = new LinkedHashSet<>();
//遍历扫描所有给定的包
for (String basePackage : basePackages) {
//调用父类ClassPathScanningCandidateComponentProvider的方法扫描给定类路径，获取符合条件的Bean定义
Set<BeanDefinition> candidates = findCandidateComponents(basePackage);
//遍历扫描到的Bean
for (BeanDefinition candidate : candidates) {
//获取Bean定义类中@Scope注解的值，即获取Bean的作用域
ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(candidate);
//为Bean设置注解配置的作用域
candidate.setScope(scopeMetadata.getScopeName());
//为Bean生成名称
String beanName = this.beanNameGenerator.generateBeanName(candidate, this.registry);
//如果扫描到的Bean不是Spring的注解Bean，则为Bean设置默认值，设置Bean的自动依赖注入装配属性等
if (candidate instanceof AbstractBeanDefinition) {
postProcessBeanDefinition((AbstractBeanDefinition) candidate, beanName);
}
//如果扫描到的Bean是Spring的注解Bean，则处理其通用的Spring注解
if (candidate instanceof AnnotatedBeanDefinition) {
//处理注解Bean中通用的注解，在分析注解Bean定义类读取器时已经分析过
AnnotationConfigUtils.processCommonDefinitionAnnotations((AnnotatedBeanDefinition) candidate);
}
//根据Bean名称检查指定的Bean是否需要在容器中注册，或者在容器中冲突
if (checkCandidate(beanName, candidate)) {
BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(candidate, beanName);
//根据注解中配置的作用域，为Bean应用相应的代理模式
definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);
beanDefinitions.add(definitionHolder);
//向容器注册扫描到的Bean
registerBeanDefinition(definitionHolder, this.registry);
}
}
}
return beanDefinitions;
}
}Bean classpath definitions ClassPathBeanDefinitionScanner scanner main call parent class by findCandidateComponents method
ClassPathScanningCandidateComponentProvider class category to scan a given package and subpackages to obtain.
(2) ClassPathScanningCandidateComponentProvider scan a given type of package and its sub-packets
Method ClassPathScanningCandidateComponentProvider findCandidateComponents class specific functions implemented by a given class scanning path package, the main source as follows:
public class ClassPathScanningCandidateComponentProvider implements EnvironmentCapable, ResourceLoaderAware {
//保存过滤规则要包含的注解，即Spring默认的@Component、@Repository、@Service、@Controller注解的Bean，以及JavaEE6的@ManagedBean和JSR-330的@Named注解
private final List<TypeFilter> includeFilters = new LinkedList<>();
//保存过滤规则要排除的注解
private final List<TypeFilter> excludeFilters = new LinkedList<>();
//构造方法，该方法在子类ClassPathBeanDefinitionScanner的构造方法中被调用
public ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters) {
this(useDefaultFilters, new StandardEnvironment());
}
public ClassPathScanningCandidateComponentProvider(boolean useDefaultFilters, Environment environment) {
//如果使用Spring默认的过滤规则，则向容器注册过滤规则
if (useDefaultFilters) {
registerDefaultFilters();
}
setEnvironment(environment);
setResourceLoader(null);
}
//向容器注册过滤规则
@SuppressWarnings("unchecked")
protected void registerDefaultFilters() {
//向要包含的过滤规则中添加@Component注解类，注意Spring中@Repository、@Service和@Controller都是Component，因为这些注解都添加了@Component注解
this.includeFilters.add(new AnnotationTypeFilter(Component.class));
//获取当前类的类加载器
ClassLoader cl = ClassPathScanningCandidateComponentProvider.class.getClassLoader();
try {
//向要包含的过滤规则添加JavaEE6的@ManagedBean注解
this.includeFilters.add(new AnnotationTypeFilter(
((Class<? extends Annotation>) ClassUtils.forName("javax.annotation.ManagedBean", cl)), false));
logger.debug("JSR-250 'javax.annotation.ManagedBean' found and supported for component scanning");
}
catch (ClassNotFoundException ex) {
// JSR-250 1.1 API (as included in Java EE 6) not available - simply skip.
}
try {
//向要包含的过滤规则添加@Named注解
this.includeFilters.add(new AnnotationTypeFilter(
((Class<? extends Annotation>) ClassUtils.forName("javax.inject.Named", cl)), false));
logger.debug("JSR-330 'javax.inject.Named' annotation found and supported for component scanning");
}
catch (ClassNotFoundException ex) {
}
}
//扫描给定类路径的包
public Set<BeanDefinition> findCandidateComponents(String basePackage) {
if (this.componentsIndex != null && indexSupportsIncludeFilters()) {
return addCandidateComponentsFromIndex(this.componentsIndex, basePackage);
}
else {
return scanCandidateComponents(basePackage);
}
}
private Set<BeanDefinition> addCandidateComponentsFromIndex(CandidateComponentsIndex index, String basePackage) {
//创建存储扫描到的类的集合
Set<BeanDefinition> candidates = new LinkedHashSet<>();
try {
Set<String> types = new HashSet<>();
for (TypeFilter filter : this.includeFilters) {
String stereotype = extractStereotype(filter);
if (stereotype == null) {
throw new IllegalArgumentException("Failed to extract stereotype from "+ filter);
}
types.addAll(index.getCandidateTypes(basePackage, stereotype));
}
boolean traceEnabled = logger.isTraceEnabled();
boolean debugEnabled = logger.isDebugEnabled();
for (String type : types) {
//为指定资源获取元数据读取器，元信息读取器通过汇编(ASM)读取资源元信息
MetadataReader metadataReader = getMetadataReaderFactory().getMetadataReader(type);
//如果扫描到的类符合容器配置的过滤规则
if (isCandidateComponent(metadataReader)) {
//通过汇编(ASM)读取资源字节码中的Bean定义元信息
AnnotatedGenericBeanDefinition sbd = new AnnotatedGenericBeanDefinition(
metadataReader.getAnnotationMetadata());
if (isCandidateComponent(sbd)) {
if (debugEnabled) {
logger.debug("Using candidate component class from index: " + type);
}
candidates.add(sbd);
}
else {
if (debugEnabled) {
logger.debug("Ignored because not a concrete top-level class: " + type);
}
}
}
else {
if (traceEnabled) {
logger.trace("Ignored because matching an exclude filter: " + type);
}
}
}
}
catch (IOException ex) {
throw new BeanDefinitionStoreException("I/O failure during classpath scanning", ex);
}
return candidates;
}
//判断元信息读取器读取的类是否符合容器定义的注解过滤规则
protected boolean isCandidateComponent(MetadataReader metadataReader) throws IOException {
//如果读取的类的注解在排除注解过滤规则中，返回false
for (TypeFilter tf : this.excludeFilters) {
if (tf.match(metadataReader, getMetadataReaderFactory())) {
return false;
}
}
//如果读取的类的注解在包含的注解的过滤规则中，则返回ture
for (TypeFilter tf : this.includeFilters) {
if (tf.match(metadataReader, getMetadataReaderFactory())) {
return isConditionMatch(metadataReader);
}
}
//如果读取的类的注解既不在排除规则，也不在包含规则中，则返回false
return false;
}
}4.AnnotationConfigWebApplicationContext load the annotations defined Bean
AnnotationConfigWebApplicationContext is AnnotationConfigApplicationContext the Web version, which is basically the same for registration and annotation Bean scan, but AnnotationConfigWebApplicationContext to comment Bean definition is slightly different load, AnnotationConfigWebApplicationContext injection annotations Bean source code is defined as follows:
//载入注解Bean定义资源
@Override
protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) {
//为容器设置注解Bean定义读取器
AnnotatedBeanDefinitionReader reader = getAnnotatedBeanDefinitionReader(beanFactory);
//为容器设置类路径Bean定义扫描器
ClassPathBeanDefinitionScanner scanner = getClassPathBeanDefinitionScanner(beanFactory);
//获取容器的Bean名称生成器
BeanNameGenerator beanNameGenerator = getBeanNameGenerator();
//为注解Bean定义读取器和类路径扫描器设置Bean名称生成器
if (beanNameGenerator != null) {
reader.setBeanNameGenerator(beanNameGenerator);
scanner.setBeanNameGenerator(beanNameGenerator);
beanFactory.registerSingleton(AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR, beanNameGenerator);
}
//获取容器的作用域元信息解析器
ScopeMetadataResolver scopeMetadataResolver = getScopeMetadataResolver();
//为注解Bean定义读取器和类路径扫描器设置作用域元信息解析器
if (scopeMetadataResolver != null) {
reader.setScopeMetadataResolver(scopeMetadataResolver);
scanner.setScopeMetadataResolver(scopeMetadataResolver);
}
if (!this.annotatedClasses.isEmpty()) {
if (logger.isInfoEnabled()) {
logger.info("Registering annotated classes: [" +
StringUtils.collectionToCommaDelimitedString(this.annotatedClasses) + "]");
}
reader.register(this.annotatedClasses.toArray(new Class<?>[this.annotatedClasses.size()]));
}
if (!this.basePackages.isEmpty()) {
if (logger.isInfoEnabled()) {
logger.info("Scanning base packages: [" +
StringUtils.collectionToCommaDelimitedString(this.basePackages) + "]");
}
scanner.scan(this.basePackages.toArray(new String[this.basePackages.size()]));
}
//获取容器定义的Bean定义资源路径
String[] configLocations = getConfigLocations();
//如果定位的Bean定义资源路径不为空
if (configLocations != null) {
for (String configLocation : configLocations) {
try {
//使用当前容器的类加载器加载定位路径的字节码类文件
Class<?> clazz = ClassUtils.forName(configLocation, getClassLoader());
if (logger.isInfoEnabled()) {
logger.info("Successfully resolved class for [" + configLocation + "]");
}
reader.register(clazz);
}
catch (ClassNotFoundException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not load class for config location [" + configLocation +
"] - trying package scan. " + ex);
}
//如果容器类加载器加载定义路径的Bean定义资源失败，则启用容器类路径扫描器扫描给定路径包及其子包中的类
int count = scanner.scan(configLocation);
if (logger.isInfoEnabled()) {
if (count == 0) {
logger.info("No annotated classes found for specified class/package [" + configLocation + "]");
}
else {
logger.info("Found " + count + " annotated classes in package [" + configLocation + "]");
}
}
}
}
}
}