BeanDefinition

• BeanDefinition

  /**

  • BeanDefinition 用于描述一个 bean 实例，包括属性值、构造参数和补充信息。
    */
    public interface BeanDefinition extends AttributeAccessor, BeanMetadataElement {

    /**

    • 标准单例 bean 的范围标识符
      */
      String SCOPE_SINGLETON = ConfigurableBeanFactory.SCOPE_SINGLETON;

    /**

    • 标准多例 bean 的范围标识符
      */
      String SCOPE_PROTOTYPE = ConfigurableBeanFactory.SCOPE_PROTOTYPE;

    /**

    • 此 bean 是应用程序的主要组成部分，通常对应于用户定义的 bean
      */
      int ROLE_APPLICATION = 0;

    /**

    • 此 bean 是一些大型配置的支持部分
    • {@link org.springframework.beans.factory.parsing.ComponentDefinition}.
      */
      int ROLE_SUPPORT = 1;

    /**

    • 此 bean 与最终用户无关，是框架基础设施的一部分
      */
      int ROLE_INFRASTRUCTURE = 2;

    // Modifiable attributes
    /**

    • 设置此 BeanDefinition 的 parent
      */
      void setParentName(@Nullable String parentName);

    /**

    • 读取此 BeanDefinition 的 parent
      */
      @Nullable
      String getParentName();

    /**

    • 设置此 BeanDefinition 关联的类名
      */
      void setBeanClassName(@Nullable String beanClassName);

    /**

    • 读取此 BeanDefinition 关联的类名
      */
      @Nullable
      String getBeanClassName();

    /**

    • 设置此 BeanDefinition 的作用域
      */
      void setScope(@Nullable String scope);

    /**

    • 读取此 BeanDefinition 的作用域
      */
      @Nullable
      String getScope();

    /**

    • 设置此 bean 的延迟初始化标识，单例、非抽象、非延迟初始化的 bean 将在启动时实例化
      */
      void setLazyInit(boolean lazyInit);

    /**

    • 读取此 bean 的延迟初始化标识
      */
      boolean isLazyInit();

    /**

    • 设置此 bean 依赖的其他 bean 名称【内部属性依赖】，
    • BeanFactory 会保证其他依赖 bean 优先初始化
      */
      void setDependsOn(@Nullable String… dependsOn);

    /**

    • 读取此 bean 依赖的其他 bean 名称
      */
      @Nullable
      String[] getDependsOn();

    /**

    • 设置此 bean 是否是依赖注入到其他 bean 的候选者
      */
      void setAutowireCandidate(boolean autowireCandidate);

    /**

    • 读取此 bean 是否是依赖注入到其他 bean 的候选者
      */
      boolean isAutowireCandidate();

    /**

    • 设置此 bean 是否是其他 bean 主要的依赖注入候选者【存在满足注入条件的多个 bean 时】
      */
      void setPrimary(boolean primary);

    /**

    • 读取此 bean 是否是其他 bean 主要的依赖注入候选者
      */
      boolean isPrimary();

    /**

    • 设置创建此 bean 的工厂 bean 名称【此 bean 是通过工厂 bean 创建的】
      */
      void setFactoryBeanName(@Nullable String factoryBeanName);

    /**

    • 读取创建此 bean 的工厂 bean 名称
      */
      @Nullable
      String getFactoryBeanName();

    /**

    • 写入创建此 bean 的工厂方法，可传递构造函数
      */
      void setFactoryMethodName(@Nullable String factoryMethodName);

    /**

    • 读取创建此 bean 的工厂方法
      */
      @Nullable
      String getFactoryMethodName();

    /**

    • 读取此 bean 的构造函数参数
      */
      ConstructorArgumentValues getConstructorArgumentValues();

    /**

    • 此 bean 是否有构造函数参数
    • @since 5.0.2
      */
      default boolean hasConstructorArgumentValues() {
      return !getConstructorArgumentValues().isEmpty();
      }

    /**

    • 读取需要注入到此 bean 的属性列表【Dependency Injection】
      */
      MutablePropertyValues getPropertyValues();

    /**

    • 此 bean 是否存在需要注入的属性列表
    • @since 5.0.2
      */
      default boolean hasPropertyValues() {
      return !getPropertyValues().isEmpty();
      }

    /**

    • 设置此 bean 的初始化方法名称
    • @since 5.1
      */
      void setInitMethodName(@Nullable String initMethodName);

    /**

    • 读取此 bean 的初始化方法名称
    • @since 5.1
      */
      @Nullable
      String getInitMethodName();

    /**

    • 写入此 bean 的销毁方法名称
    • @since 5.1
      */
      void setDestroyMethodName(@Nullable String destroyMethodName);

    /**

    • 读取此 bean 的销毁方法名称
    • Return the name of the destroy method.
    • @since 5.1
      */
      @Nullable
      String getDestroyMethodName();

    /**

    • 写入此 bean 的角色
    • @since 5.1
    • @see #ROLE_APPLICATION
    • @see #ROLE_SUPPORT
    • @see #ROLE_INFRASTRUCTURE
      */
      void setRole(int role);

    /**

    • 读取此 bean 的角色
      */
      int getRole();

    /**

    • 写入此 bean 的描述信息
    • @since 5.1
      */
      void setDescription(@Nullable String description);

    /**

    • 读取此 bean 的描述信息
      */
      @Nullable
      String getDescription();

    // Read-only attributes
    /**

    • 此 bean 是否是可共享的单例
      */
      boolean isSingleton();

    /**

    • 此 bean 是否是多例
      */
      boolean isPrototype();

    /**

    • 此 bean 是否是抽象的，不能实例化
      */
      boolean isAbstract();

    /**

    • 此 BeanDefinition 的来源
      */
      @Nullable
      String getResourceDescription();

    /**

    • 读取原始的 BeanDefinition，未加装饰
      */
      @Nullable
      BeanDefinition getOriginatingBeanDefinition();
      }

• AbstractBeanDefinition：BeanDefinition 接口的核心实现

  /**

  • 羽翼丰满的 BeanDefinition 基础类
    / @SuppressWarnings("serial") public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccessor implements BeanDefinition, Cloneable { /*

    • 默认的作用域名称，等同于 singleton
      */
      public static final String SCOPE_DEFAULT = "";

    /**

    • 不执行自动注入
      */
      public static final int AUTOWIRE_NO = AutowireCapableBeanFactory.AUTOWIRE_NO;

    /**

    • 根据属性名称自动注入
      */
      public static final int AUTOWIRE_BY_NAME = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;

    /**

    • 根据属性类型自动注入
      */
      public static final int AUTOWIRE_BY_TYPE = AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE;

    /**

    • 根据构造函数自动注入
      */
      public static final int AUTOWIRE_CONSTRUCTOR = AutowireCapableBeanFactory.AUTOWIRE_CONSTRUCTOR;

    @Deprecated
    public static final int AUTOWIRE_AUTODETECT = AutowireCapableBeanFactory.AUTOWIRE_AUTODETECT;

    /**

    • 此 bean 不需要执行依赖检查
      */
      public static final int DEPENDENCY_CHECK_NONE = 0;

    /**

    • 此 bean 需要执行对象引用的依赖检查
      */
      public static final int DEPENDENCY_CHECK_OBJECTS = 1;

    /**

    • 此 bean 需要执行简单属性的依赖检查
      */
      public static final int DEPENDENCY_CHECK_SIMPLE = 2;

    /**

    • 此 bean 需要对所有属性执行依赖检查
      */
      public static final int DEPENDENCY_CHECK_ALL = 3;

    /**

    • 此 bean 需要自动推断销毁方法的名称
      */
      public static final String INFER_METHOD = "(inferred)";

    @Nullable
    private volatile Object beanClass;

    @Nullable
    private String scope = SCOPE_DEFAULT;

    private boolean abstractFlag = false;

    private boolean lazyInit = false;

    private int autowireMode = AUTOWIRE_NO;

    private int dependencyCheck = DEPENDENCY_CHECK_NONE;

    @Nullable
    private String[] dependsOn;

    private boolean autowireCandidate = true;

    private boolean primary = false;

    private final Map qualifiers = new LinkedHashMap<>();

    /**

    • 实例生成器
      */
      @Nullable
      private Supplier instanceSupplier;

    private boolean nonPublicAccessAllowed = true;

    private boolean lenientConstructorResolution = true;

    @Nullable
    private String factoryBeanName;

    @Nullable
    private String factoryMethodName;

    @Nullable
    private ConstructorArgumentValues constructorArgumentValues;

    @Nullable
    private MutablePropertyValues propertyValues;

    @Nullable
    private MethodOverrides methodOverrides;

    @Nullable
    private String initMethodName;

    @Nullable
    private String destroyMethodName;

    /**

    • 强制执行初始化方法
      */
      private boolean enforceInitMethod = true;

    /**

    • 强制执行销毁方法
      */
      private boolean enforceDestroyMethod = true;

    /**

    • 此 bean 是否是合成的
      */
      private boolean synthetic = false;

    private int role = BeanDefinition.ROLE_APPLICATION;

    @Nullable
    private String description;

    @Nullable
    private Resource resource;

    protected AbstractBeanDefinition() {
    this(null, null);
    }

    protected AbstractBeanDefinition(@Nullable ConstructorArgumentValues cargs, @Nullable MutablePropertyValues pvs) {
    constructorArgumentValues = cargs;
    propertyValues = pvs;
    }

    protected AbstractBeanDefinition(BeanDefinition original) {
    setParentName(original.getParentName());
    setBeanClassName(original.getBeanClassName());
    setScope(original.getScope());
    setAbstract(original.isAbstract());
    setLazyInit(original.isLazyInit());
    setFactoryBeanName(original.getFactoryBeanName());
    setFactoryMethodName(original.getFactoryMethodName());
    setRole(original.getRole());
    setSource(original.getSource());
    copyAttributesFrom(original);

    if (original instanceof AbstractBeanDefinition) {
        final AbstractBeanDefinition originalAbd = (AbstractBeanDefinition) original;
        if (originalAbd.hasBeanClass()) {
            setBeanClass(originalAbd.getBeanClass());
        }
        if (originalAbd.hasConstructorArgumentValues()) {
            setConstructorArgumentValues(new ConstructorArgumentValues(original.getConstructorArgumentValues()));
        }
        if (originalAbd.hasPropertyValues()) {
            setPropertyValues(new MutablePropertyValues(original.getPropertyValues()));
        }
        if (originalAbd.hasMethodOverrides()) {
            setMethodOverrides(new MethodOverrides(originalAbd.getMethodOverrides()));
        }
        setAutowireMode(originalAbd.getAutowireMode());
        setDependencyCheck(originalAbd.getDependencyCheck());
        setDependsOn(originalAbd.getDependsOn());
        setAutowireCandidate(originalAbd.isAutowireCandidate());
        setPrimary(originalAbd.isPrimary());
        copyQualifiersFrom(originalAbd);
        setInstanceSupplier(originalAbd.getInstanceSupplier());
        setNonPublicAccessAllowed(originalAbd.isNonPublicAccessAllowed());
        setLenientConstructorResolution(originalAbd.isLenientConstructorResolution());
        setInitMethodName(originalAbd.getInitMethodName());
        setEnforceInitMethod(originalAbd.isEnforceInitMethod());
        setDestroyMethodName(originalAbd.getDestroyMethodName());
        setEnforceDestroyMethod(originalAbd.isEnforceDestroyMethod());
        setSynthetic(originalAbd.isSynthetic());
        setResource(originalAbd.getResource());
    }
    else {
        setConstructorArgumentValues(new ConstructorArgumentValues(original.getConstructorArgumentValues()));
        setPropertyValues(new MutablePropertyValues(original.getPropertyValues()));
        setResourceDescription(original.getResourceDescription());
    }

    }

    public void overrideFrom(BeanDefinition other) {
    if (StringUtils.hasLength(other.getBeanClassName())) {
    setBeanClassName(other.getBeanClassName());
    }
    if (StringUtils.hasLength(other.getScope())) {
    setScope(other.getScope());
    }
    setAbstract(other.isAbstract());
    setLazyInit(other.isLazyInit());
    if (StringUtils.hasLength(other.getFactoryBeanName())) {
    setFactoryBeanName(other.getFactoryBeanName());
    }
    if (StringUtils.hasLength(other.getFactoryMethodName())) {
    setFactoryMethodName(other.getFactoryMethodName());
    }
    setRole(other.getRole());
    setSource(other.getSource());
    copyAttributesFrom(other);

    if (other instanceof AbstractBeanDefinition) {
        final AbstractBeanDefinition otherAbd = (AbstractBeanDefinition) other;
        if (otherAbd.hasBeanClass()) {
            setBeanClass(otherAbd.getBeanClass());
        }
        if (otherAbd.hasConstructorArgumentValues()) {
            getConstructorArgumentValues().addArgumentValues(other.getConstructorArgumentValues());
        }
        if (otherAbd.hasPropertyValues()) {
            getPropertyValues().addPropertyValues(other.getPropertyValues());
        }
        if (otherAbd.hasMethodOverrides()) {
            getMethodOverrides().addOverrides(otherAbd.getMethodOverrides());
        }
        setAutowireMode(otherAbd.getAutowireMode());
        setDependencyCheck(otherAbd.getDependencyCheck());
        setDependsOn(otherAbd.getDependsOn());
        setAutowireCandidate(otherAbd.isAutowireCandidate());
        setPrimary(otherAbd.isPrimary());
        copyQualifiersFrom(otherAbd);
        setInstanceSupplier(otherAbd.getInstanceSupplier());
        setNonPublicAccessAllowed(otherAbd.isNonPublicAccessAllowed());
        setLenientConstructorResolution(otherAbd.isLenientConstructorResolution());
        if (otherAbd.getInitMethodName() != null) {
            setInitMethodName(otherAbd.getInitMethodName());
            setEnforceInitMethod(otherAbd.isEnforceInitMethod());
        }
        if (otherAbd.getDestroyMethodName() != null) {
            setDestroyMethodName(otherAbd.getDestroyMethodName());
            setEnforceDestroyMethod(otherAbd.isEnforceDestroyMethod());
        }
        setSynthetic(otherAbd.isSynthetic());
        setResource(otherAbd.getResource());
    }
    else {
        getConstructorArgumentValues().addArgumentValues(other.getConstructorArgumentValues());
        getPropertyValues().addPropertyValues(other.getPropertyValues());
        setResourceDescription(other.getResourceDescription());
    }

    }

    /**

    • 将默认值应用到此 BeanDefinition
      */
      public void applyDefaults(BeanDefinitionDefaults defaults) {
      setLazyInit(defaults.isLazyInit());
      setAutowireMode(defaults.getAutowireMode());
      setDependencyCheck(defaults.getDependencyCheck());
      setInitMethodName(defaults.getInitMethodName());
      setEnforceInitMethod(false);
      setDestroyMethodName(defaults.getDestroyMethodName());
      setEnforceDestroyMethod(false);
      }

    @Override
    public void setBeanClassName(@Nullable String beanClassName) {
    beanClass = beanClassName;
    }

    @Override
    @Nullable
    public String getBeanClassName() {
    final Object beanClassObject = beanClass;
    if (beanClassObject instanceof Class) {
    return ((Class) beanClassObject).getName();
    }
    else {
    return (String) beanClassObject;
    }
    }

    public void setBeanClass(@Nullable Class beanClass) {
    this.beanClass = beanClass;
    }

    public Class getBeanClass() throws IllegalStateException {
    final Object beanClassObject = beanClass;
    if (beanClassObject == null) {
    throw new IllegalStateException("No bean class specified on bean definition");
    }
    if (!(beanClassObject instanceof Class)) {
    throw new IllegalStateException(
    "Bean class name [" + beanClassObject + "] has not been resolved into an actual Class");
    }
    return (Class) beanClassObject;
    }

    public boolean hasBeanClass() {
    return beanClass instanceof Class;
    }

    @Nullable
    public Class resolveBeanClass(@Nullable ClassLoader classLoader) throws ClassNotFoundException {
    final String className = getBeanClassName();
    if (className == null) {
    return null;
    }
    final Class resolvedClass = ClassUtils.forName(className, classLoader);
    beanClass = resolvedClass;
    return resolvedClass;
    }

    @Override
    public void setScope(@Nullable String scope) {
    this.scope = scope;
    }

    @Override
    @Nullable
    public String getScope() {
    return scope;
    }

    @Override
    public boolean isSingleton() {
    return SCOPE_SINGLETON.equals(scope) || SCOPE_DEFAULT.equals(scope);
    }

    @Override
    public boolean isPrototype() {
    return SCOPE_PROTOTYPE.equals(scope);
    }

    public void setAbstract(boolean abstractFlag) {
    this.abstractFlag = abstractFlag;
    }

    @Override
    public boolean isAbstract() {
    return abstractFlag;
    }

    @Override
    public void setLazyInit(boolean lazyInit) {
    this.lazyInit = lazyInit;
    }

    @Override
    public boolean isLazyInit() {
    return lazyInit;
    }

    /**

    • @see #AUTOWIRE_NO
    • @see #AUTOWIRE_BY_NAME
    • @see #AUTOWIRE_BY_TYPE
    • @see #AUTOWIRE_CONSTRUCTOR
    • @see #AUTOWIRE_AUTODETECT
      */
      public void setAutowireMode(int autowireMode) {
      this.autowireMode = autowireMode;
      }

    public int getAutowireMode() {
    return autowireMode;
    }

    public int getResolvedAutowireMode() {
    if (autowireMode == AUTOWIRE_AUTODETECT) {
    // Work out whether to apply setter autowiring or constructor autowiring.
    // If it has a no-arg constructor it's deemed to be setter autowiring,
    // otherwise we'll try constructor autowiring.
    final Constructor[] constructors = getBeanClass().getConstructors();
    for (final Constructor constructor : constructors) {
    if (constructor.getParameterCount() == 0) {
    // 如果有无参数的构造函数，则按照类型注入
    return AUTOWIRE_BY_TYPE;
    }
    }
    return AUTOWIRE_CONSTRUCTOR;
    }
    else {
    return autowireMode;
    }
    }

    public void setDependencyCheck(int dependencyCheck) {
    this.dependencyCheck = dependencyCheck;
    }

    public int getDependencyCheck() {
    return dependencyCheck;
    }

    @Override
    public void setDependsOn(@Nullable String… dependsOn) {
    this.dependsOn = dependsOn;
    }

    @Override
    @Nullable
    public String[] getDependsOn() {
    return dependsOn;
    }

    @Override
    public void setAutowireCandidate(boolean autowireCandidate) {
    this.autowireCandidate = autowireCandidate;
    }

    @Override
    public boolean isAutowireCandidate() {
    return autowireCandidate;
    }

    @Override
    public void setPrimary(boolean primary) {
    this.primary = primary;
    }

    @Override
    public boolean isPrimary() {
    return primary;
    }

    public void addQualifier(AutowireCandidateQualifier qualifier) {
    qualifiers.put(qualifier.getTypeName(), qualifier);
    }

    public boolean hasQualifier(String typeName) {
    return qualifiers.keySet().contains(typeName);
    }

    @Nullable
    public AutowireCandidateQualifier getQualifier(String typeName) {
    return qualifiers.get(typeName);
    }

    public Set getQualifiers() {
    return new LinkedHashSet<>(qualifiers.values());
    }

    public void copyQualifiersFrom(AbstractBeanDefinition source) {
    Assert.notNull(source, "Source must not be null");
    qualifiers.putAll(source.qualifiers);
    }

    public void setInstanceSupplier(@Nullable Supplier instanceSupplier) {
    this.instanceSupplier = instanceSupplier;
    }

    @Nullable
    public Supplier getInstanceSupplier() {
    return instanceSupplier;
    }

    /**

    • 是否允许指向此 bean 的外部化元素，访问非公共构造函数和方法。
    • 注解的 private 属性不需要 setter 方法即可注入
      */
      public void setNonPublicAccessAllowed(boolean nonPublicAccessAllowed) {
      this.nonPublicAccessAllowed = nonPublicAccessAllowed;
      }

    public boolean isNonPublicAccessAllowed() {
    return nonPublicAccessAllowed;
    }

    /**

    • 是否在宽大模式下解析构造函数
      */
      public void setLenientConstructorResolution(boolean lenientConstructorResolution) {
      this.lenientConstructorResolution = lenientConstructorResolution;
      }

    public boolean isLenientConstructorResolution() {
    return lenientConstructorResolution;
    }

    @Override
    public void setFactoryBeanName(@Nullable String factoryBeanName) {
    this.factoryBeanName = factoryBeanName;
    }

    @Override
    @Nullable
    public String getFactoryBeanName() {
    return factoryBeanName;
    }

    @Override
    public void setFactoryMethodName(@Nullable String factoryMethodName) {
    this.factoryMethodName = factoryMethodName;
    }

    @Override
    @Nullable
    public String getFactoryMethodName() {
    return factoryMethodName;
    }

    public void setConstructorArgumentValues(ConstructorArgumentValues constructorArgumentValues) {
    this.constructorArgumentValues = constructorArgumentValues;
    }

    @Override
    public ConstructorArgumentValues getConstructorArgumentValues() {
    if (constructorArgumentValues == null) {
    constructorArgumentValues = new ConstructorArgumentValues();
    }
    return constructorArgumentValues;
    }

    @Override
    public boolean hasConstructorArgumentValues() {
    return constructorArgumentValues != null && !constructorArgumentValues.isEmpty();
    }

    public void setPropertyValues(MutablePropertyValues propertyValues) {
    this.propertyValues = propertyValues;
    }

    @Override
    public MutablePropertyValues getPropertyValues() {
    if (propertyValues == null) {
    propertyValues = new MutablePropertyValues();
    }
    return propertyValues;
    }

    @Override
    public boolean hasPropertyValues() {
    return propertyValues != null && !propertyValues.isEmpty();
    }

    public void setMethodOverrides(MethodOverrides methodOverrides) {
    this.methodOverrides = methodOverrides;
    }

    public MethodOverrides getMethodOverrides() {
    if (methodOverrides == null) {
    methodOverrides = new MethodOverrides();
    }
    return methodOverrides;
    }

    public boolean hasMethodOverrides() {
    return methodOverrides != null && !methodOverrides.isEmpty();
    }

    @Override
    public void setInitMethodName(@Nullable String initMethodName) {
    this.initMethodName = initMethodName;
    }

    @Override
    @Nullable
    public String getInitMethodName() {
    return initMethodName;
    }

    public void setEnforceInitMethod(boolean enforceInitMethod) {
    this.enforceInitMethod = enforceInitMethod;
    }

    public boolean isEnforceInitMethod() {
    return enforceInitMethod;
    }

    @Override
    public void setDestroyMethodName(@Nullable String destroyMethodName) {
    this.destroyMethodName = destroyMethodName;
    }

    @Override
    @Nullable
    public String getDestroyMethodName() {
    return destroyMethodName;
    }

    public void setEnforceDestroyMethod(boolean enforceDestroyMethod) {
    this.enforceDestroyMethod = enforceDestroyMethod;
    }

    public boolean isEnforceDestroyMethod() {
    return enforceDestroyMethod;
    }

    public void setSynthetic(boolean synthetic) {
    this.synthetic = synthetic;
    }

    public boolean isSynthetic() {
    return synthetic;
    }

    @Override
    public void setRole(int role) {
    this.role = role;
    }

    @Override
    public int getRole() {
    return role;
    }

    @Override
    public void setDescription(@Nullable String description) {
    this.description = description;
    }

    @Override
    @Nullable
    public String getDescription() {
    return description;
    }

    public void setResource(@Nullable Resource resource) {
    this.resource = resource;
    }

    @Nullable
    public Resource getResource() {
    return resource;
    }

    public void setResourceDescription(@Nullable String resourceDescription) {
    resource = resourceDescription != null ? new DescriptiveResource(resourceDescription) : null;
    }

    @Override
    @Nullable
    public String getResourceDescription() {
    return resource != null ? resource.getDescription() : null;
    }

    public void setOriginatingBeanDefinition(BeanDefinition originatingBd) {
    resource = new BeanDefinitionResource(originatingBd);
    }

    @Override
    @Nullable
    public BeanDefinition getOriginatingBeanDefinition() {
    return resource instanceof BeanDefinitionResource ?
    ((BeanDefinitionResource) resource).getBeanDefinition() : null;
    }

    /**

    • 验证此 BeanDefinition
      */
      public void validate() throws BeanDefinitionValidationException {
      if (hasMethodOverrides() && getFactoryMethodName() != null) {
      throw new BeanDefinitionValidationException(
      "Cannot combine static factory method with method overrides: " +
      "the static factory method must create the instance");
      }

      if (hasBeanClass()) {
      prepareMethodOverrides();
      }
      }

    public void prepareMethodOverrides() throws BeanDefinitionValidationException {
    // Check that lookup methods exists.
    if (hasMethodOverrides()) {
    final Set overrides = getMethodOverrides().getOverrides();
    synchronized (overrides) {
    for (final MethodOverride mo : overrides) {
    prepareMethodOverride(mo);
    }
    }
    }
    }

    protected void prepareMethodOverride(MethodOverride mo) throws BeanDefinitionValidationException {
    final int count = ClassUtils.getMethodCountForName(getBeanClass(), mo.getMethodName());
    if (count == 0) {
    throw new BeanDefinitionValidationException(
    "Invalid method override: no method with name '" + mo.getMethodName() +
    "' on class [" + getBeanClassName() + "]");
    }
    else if (count == 1) {
    // Mark override as not overloaded, to avoid the overhead of arg type checking.
    mo.setOverloaded(false);
    }
    }

    @Override
    public Object clone() {
    return cloneBeanDefinition();
    }

    /**

    • 克隆此 BeanDefinition
      */
      public abstract AbstractBeanDefinition cloneBeanDefinition();

    @Override
    public boolean equals(Object other) {
    if (this == other) {
    return true;
    }
    if (!(other instanceof AbstractBeanDefinition)) {
    return false;
    }
    final AbstractBeanDefinition that = (AbstractBeanDefinition) other;
    boolean rtn = ObjectUtils.nullSafeEquals(getBeanClassName(), that.getBeanClassName());
    rtn = rtn &= ObjectUtils.nullSafeEquals(scope, that.scope);
    rtn = rtn &= abstractFlag == that.abstractFlag;
    rtn = rtn &= lazyInit == that.lazyInit;
    rtn = rtn &= autowireMode == that.autowireMode;
    rtn = rtn &= dependencyCheck == that.dependencyCheck;
    rtn = rtn &= Arrays.equals(dependsOn, that.dependsOn);
    rtn = rtn &= autowireCandidate == that.autowireCandidate;
    rtn = rtn &= ObjectUtils.nullSafeEquals(qualifiers, that.qualifiers);
    rtn = rtn &= primary == that.primary;
    rtn = rtn &= nonPublicAccessAllowed == that.nonPublicAccessAllowed;
    rtn = rtn &= lenientConstructorResolution == that.lenientConstructorResolution;
    rtn = rtn &= ObjectUtils.nullSafeEquals(constructorArgumentValues, that.constructorArgumentValues);
    rtn = rtn &= ObjectUtils.nullSafeEquals(propertyValues, that.propertyValues);
    rtn = rtn &= ObjectUtils.nullSafeEquals(methodOverrides, that.methodOverrides);
    rtn = rtn &= ObjectUtils.nullSafeEquals(factoryBeanName, that.factoryBeanName);
    rtn = rtn &= ObjectUtils.nullSafeEquals(factoryMethodName, that.factoryMethodName);
    rtn = rtn &= ObjectUtils.nullSafeEquals(initMethodName, that.initMethodName);
    rtn = rtn &= enforceInitMethod == that.enforceInitMethod;
    rtn = rtn &= ObjectUtils.nullSafeEquals(destroyMethodName, that.destroyMethodName);
    rtn = rtn &= enforceDestroyMethod == that.enforceDestroyMethod;
    rtn = rtn &= synthetic == that.synthetic;
    rtn = rtn &= role == that.role;
    return rtn && super.equals(other);
    }

    @Override
    public int hashCode() {
    int hashCode = ObjectUtils.nullSafeHashCode(getBeanClassName());
    hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(scope);
    hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(constructorArgumentValues);
    hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(propertyValues);
    hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(factoryBeanName);
    hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(factoryMethodName);
    hashCode = 29 * hashCode + super.hashCode();
    return hashCode;
    }

    @Override
    public String toString() {
    final StringBuilder sb = new StringBuilder("class [");
    sb.append(getBeanClassName()).append("]");
    sb.append("; scope=").append(scope);
    sb.append("; abstract=").append(abstractFlag);
    sb.append("; lazyInit=").append(lazyInit);
    sb.append("; autowireMode=").append(autowireMode);
    sb.append("; dependencyCheck=").append(dependencyCheck);
    sb.append("; autowireCandidate=").append(autowireCandidate);
    sb.append("; primary=").append(primary);
    sb.append("; factoryBeanName=").append(factoryBeanName);
    sb.append("; factoryMethodName=").append(factoryMethodName);
    sb.append("; initMethodName=").append(initMethodName);
    sb.append("; destroyMethodName=").append(destroyMethodName);
    if (resource != null) {
    sb.append("; defined in ").append(resource.getDescription());
    }
    return sb.toString();
    }
    }

• RootBeanDefinition

  /**

  • 合并的 BeanDefinition
    / @SuppressWarnings("serial") public class RootBeanDefinition extends AbstractBeanDefinition { /*

    • 持有 bean 名称、bean 别名和 BeanDefinition 的包装器
      / @Nullable private BeanDefinitionHolder decoratedDefinition; /*
    • 注解元素
      / @Nullable private AnnotatedElement qualifiedElement; /*
    • 允许缓存
      */
      boolean allowCaching = true;

    boolean isFactoryMethodUnique = false;

    @Nullable
    volatile ResolvableType targetType;

    /** 此 BeanDefinition 关联的 Class 类型 */
    @Nullable
    volatile Class resolvedTargetType;

    /** 泛型工厂方法的返回类型 */
    @Nullable
    volatile ResolvableType factoryMethodReturnType;

    /** 缓存用于内省的惟一工厂方法 */
    @Nullable
    volatile Method factoryMethodToIntrospect;

    /** 以下 4 个构造函数的锁 */
    final Object constructorArgumentLock = new Object();

    /** 已解析的构造函数或工厂方法 */
    @Nullable
    Executable resolvedConstructorOrFactoryMethod;

    /** 构造函数参数是否已解析 */
    boolean constructorArgumentsResolved = false;

    /** 已解析的构造函数参数 */
    @Nullable
    Object[] resolvedConstructorArguments;

    /** 部分准备的构造函数参数 */
    @Nullable
    Object[] preparedConstructorArguments;

    /** Common lock for the two post-processing fields below. */
    final Object postProcessingLock = new Object();

    /** 是否已应用了 MergedBeanDefinitionPostProcessor */
    boolean postProcessed = false;

    /** before-instantiation post-processor 已启动 */
    @Nullable
    volatile Boolean beforeInstantiationResolved;

    /**

    • 外部管理的配置成员
      */
      @Nullable
      private Set externallyManagedConfigMembers;

    /**

    • 外部管理的初始化方法
      */
      @Nullable
      private Set externallyManagedInitMethods;

    /**

    • 外部管理的销毁方法
      */
      @Nullable
      private Set externallyManagedDestroyMethods;

    public RootBeanDefinition() {
    super();
    }

    public RootBeanDefinition(@Nullable Class beanClass) {
    super();
    setBeanClass(beanClass);
    }

    public RootBeanDefinition(@Nullable Class beanClass, @Nullable Supplier instanceSupplier) {
    super();
    setBeanClass(beanClass);
    setInstanceSupplier(instanceSupplier);
    }

    public RootBeanDefinition(@Nullable Class beanClass, String scope, @Nullable Supplier instanceSupplier) {
    super();
    setBeanClass(beanClass);
    setScope(scope);
    setInstanceSupplier(instanceSupplier);
    }

    */
    public RootBeanDefinition(@Nullable Class beanClass, int autowireMode, boolean dependencyCheck) {
    super();
    setBeanClass(beanClass);
    setAutowireMode(autowireMode);
    if (dependencyCheck && getResolvedAutowireMode() != AUTOWIRE_CONSTRUCTOR) {
    setDependencyCheck(DEPENDENCY_CHECK_OBJECTS);
    }
    }

    public RootBeanDefinition(@Nullable Class beanClass, @Nullable ConstructorArgumentValues cargs,
    @Nullable MutablePropertyValues pvs) {
    super(cargs, pvs);
    setBeanClass(beanClass);
    }

    public RootBeanDefinition(String beanClassName) {
    setBeanClassName(beanClassName);
    }

    public RootBeanDefinition(String beanClassName, ConstructorArgumentValues cargs, MutablePropertyValues pvs) {
    super(cargs, pvs);
    setBeanClassName(beanClassName);
    }

    public RootBeanDefinition(RootBeanDefinition original) {
    super(original);
    decoratedDefinition = original.decoratedDefinition;
    qualifiedElement = original.qualifiedElement;
    allowCaching = original.allowCaching;
    isFactoryMethodUnique = original.isFactoryMethodUnique;
    targetType = original.targetType;
    }

    RootBeanDefinition(BeanDefinition original) {
    super(original);
    }

    @Override
    public String getParentName() {
    return null;
    }

    @Override
    public void setParentName(@Nullable String parentName) {
    if (parentName != null) {
    throw new IllegalArgumentException("Root bean cannot be changed into a child bean with parent reference");
    }
    }

    public void setDecoratedDefinition(@Nullable BeanDefinitionHolder decoratedDefinition) {
    this.decoratedDefinition = decoratedDefinition;
    }

    @Nullable
    public BeanDefinitionHolder getDecoratedDefinition() {
    return decoratedDefinition;
    }

    public void setQualifiedElement(@Nullable AnnotatedElement qualifiedElement) {
    this.qualifiedElement = qualifiedElement;
    }

    @Nullable
    public AnnotatedElement getQualifiedElement() {
    return qualifiedElement;
    }

    public void setTargetType(ResolvableType targetType) {
    this.targetType = targetType;
    }

    public void setTargetType(@Nullable Class targetType) {
    this.targetType = targetType != null ? ResolvableType.forClass(targetType) : null;
    }

    @Nullable
    public Class getTargetType() {
    if (resolvedTargetType != null) {
    return resolvedTargetType;
    }
    final ResolvableType targetType = this.targetType;
    return targetType != null ? targetType.resolve() : null;
    }

    public ResolvableType getResolvableType() {
    final ResolvableType targetType = this.targetType;
    return targetType != null ? targetType : ResolvableType.forClass(getBeanClass());
    }

    @Nullable
    public Constructor[] getPreferredConstructors() {
    return null;
    }

    public void setUniqueFactoryMethodName(String name) {
    Assert.hasText(name, "Factory method name must not be empty");
    setFactoryMethodName(name);
    isFactoryMethodUnique = true;
    }

    public boolean isFactoryMethod(Method candidate) {
    return candidate.getName().equals(getFactoryMethodName());
    }

    @Nullable
    public Method getResolvedFactoryMethod() {
    return factoryMethodToIntrospect;
    }

    public void registerExternallyManagedConfigMember(Member configMember) {
    synchronized (postProcessingLock) {
    if (externallyManagedConfigMembers == null) {
    externallyManagedConfigMembers = new HashSet<>(1);
    }
    externallyManagedConfigMembers.add(configMember);
    }
    }

    public boolean isExternallyManagedConfigMember(Member configMember) {
    synchronized (postProcessingLock) {
    return externallyManagedConfigMembers != null &&
    externallyManagedConfigMembers.contains(configMember);
    }
    }

    /**

    • @PostConstruct
      */
      public void registerExternallyManagedInitMethod(String initMethod) {
      synchronized (postProcessingLock) {
      if (externallyManagedInitMethods == null) {
      externallyManagedInitMethods = new HashSet<>(1);
      }
      externallyManagedInitMethods.add(initMethod);
      }
      }

    public boolean isExternallyManagedInitMethod(String initMethod) {
    synchronized (postProcessingLock) {
    return externallyManagedInitMethods != null &&
    externallyManagedInitMethods.contains(initMethod);
    }
    }

    /**

    • @PreDestroy
      */
      public void registerExternallyManagedDestroyMethod(String destroyMethod) {
      synchronized (postProcessingLock) {
      if (externallyManagedDestroyMethods == null) {
      externallyManagedDestroyMethods = new HashSet<>(1);
      }
      externallyManagedDestroyMethods.add(destroyMethod);
      }
      }

    public boolean isExternallyManagedDestroyMethod(String destroyMethod) {
    synchronized (postProcessingLock) {
    return externallyManagedDestroyMethods != null &&
    externallyManagedDestroyMethods.contains(destroyMethod);
    }
    }

    @Override
    public RootBeanDefinition cloneBeanDefinition() {
    return new RootBeanDefinition(this);
    }

    @Override
    public boolean equals(Object other) {
    return this == other || other instanceof RootBeanDefinition && super.equals(other);
    }

    @Override
    public String toString() {
    return "Root bean: " + super.toString();
    }
    }

• GenericBeanDefinition

  /**

  • 标准 bean 定义的 GenericBeanDefinition，主要用于 XML 配置中的 bean
    */
    @SuppressWarnings("serial")
    public class GenericBeanDefinition extends AbstractBeanDefinition {
    @Nullable
    private String parentName;

    public GenericBeanDefinition() {
    super();
    }

    public GenericBeanDefinition(BeanDefinition original) {
    super(original);
    }

    @Override
    public void setParentName(@Nullable String parentName) {
    this.parentName = parentName;
    }

    @Override
    @Nullable
    public String getParentName() {
    return this.parentName;
    }

    @Override
    public AbstractBeanDefinition cloneBeanDefinition() {
    return new GenericBeanDefinition(this);
    }

    @Override
    public boolean equals(Object other) {
    return (this == other || (other instanceof GenericBeanDefinition && super.equals(other)));
    }

    @Override
    public String toString() {
    StringBuilder sb = new StringBuilder("Generic bean");
    if (this.parentName != null) {
    sb.append(" with parent '").append(this.parentName).append("'");
    }
    sb.append(": ").append(super.toString());
    return sb.toString();
    }
    }

• ScannedGenericBeanDefinition

  /**

  • 基于包扫描发现，通过注解加入到容器中的 BeanDefinition
    / @SuppressWarnings("serial") public class ScannedGenericBeanDefinition extends GenericBeanDefinition implements AnnotatedBeanDefinition { /*

    • 注解元数据
      */
      private final AnnotationMetadata metadata;

    public ScannedGenericBeanDefinition(MetadataReader metadataReader) {
    Assert.notNull(metadataReader, "MetadataReader must not be null");
    this.metadata = metadataReader.getAnnotationMetadata();
    setBeanClassName(this.metadata.getClassName());
    }

    @Override
    public final AnnotationMetadata getMetadata() {
    return this.metadata;
    }

    @Override
    @Nullable
    public MethodMetadata getFactoryMethodMetadata() {
    return null;
    }
    }

• AnnotatedGenericBeanDefinition

  @SuppressWarnings("serial")
  public class AnnotatedGenericBeanDefinition extends GenericBeanDefinition implements AnnotatedBeanDefinition {
  /**
  * 类注解元数据
  / private final AnnotationMetadata metadata; /*
  * 方法元数据
  */
  @Nullable
  private MethodMetadata factoryMethodMetadata;

  public AnnotatedGenericBeanDefinition(Class<?> beanClass) {
      setBeanClass(beanClass);
      metadata = new StandardAnnotationMetadata(beanClass, true);
  }
  
  public AnnotatedGenericBeanDefinition(AnnotationMetadata metadata) {
      Assert.notNull(metadata, "AnnotationMetadata must not be null");
      if (metadata instanceof StandardAnnotationMetadata) {
          setBeanClass(((StandardAnnotationMetadata) metadata).getIntrospectedClass());
      }
      else {
          setBeanClassName(metadata.getClassName());
      }
      this.metadata = metadata;
  }
  
  public AnnotatedGenericBeanDefinition(AnnotationMetadata metadata, MethodMetadata factoryMethodMetadata) {
      this(metadata);
      Assert.notNull(factoryMethodMetadata, "MethodMetadata must not be null");
      setFactoryMethodName(factoryMethodMetadata.getMethodName());
      this.factoryMethodMetadata = factoryMethodMetadata;
  }
  
  @Override
  public final AnnotationMetadata getMetadata() {
      return metadata;
  }
  
  @Override
  @Nullable
  public final MethodMetadata getFactoryMethodMetadata() {
      return factoryMethodMetadata;
  }

  }

• ConfigurationClassBeanDefinition

  ConfigurationClassBeanDefinitionReader#
  /**

  • 配置类 BeanDefinition、包括通过 @Bean 注解创建的 BeanDefinition
    / private static class ConfigurationClassBeanDefinition extends RootBeanDefinition implements AnnotatedBeanDefinition { /*

    • 类注解元数据
      / private final AnnotationMetadata annotationMetadata; /*
    • 方法元数据
      */
      private final MethodMetadata factoryMethodMetadata;

    public ConfigurationClassBeanDefinition(ConfigurationClass configClass, MethodMetadata beanMethodMetadata) {
    this.annotationMetadata = configClass.getMetadata();
    this.factoryMethodMetadata = beanMethodMetadata;
    setLenientConstructorResolution(false);
    }

    public ConfigurationClassBeanDefinition(
    RootBeanDefinition original, ConfigurationClass configClass, MethodMetadata beanMethodMetadata) {
    super(original);
    this.annotationMetadata = configClass.getMetadata();
    this.factoryMethodMetadata = beanMethodMetadata;
    }

    private ConfigurationClassBeanDefinition(ConfigurationClassBeanDefinition original) {
    super(original);
    this.annotationMetadata = original.annotationMetadata;
    this.factoryMethodMetadata = original.factoryMethodMetadata;
    }

    @Override
    public AnnotationMetadata getMetadata() {
    return this.annotationMetadata;
    }

    @Override
    public MethodMetadata getFactoryMethodMetadata() {
    return this.factoryMethodMetadata;
    }

    @Override
    public boolean isFactoryMethod(Method candidate) {
    return (super.isFactoryMethod(candidate) && BeanAnnotationHelper.isBeanAnnotated(candidate));
    }

    @Override
    public ConfigurationClassBeanDefinition cloneBeanDefinition() {
    return new ConfigurationClassBeanDefinition(this);
    }
    }