# 程序包的使用
org.springframework.core

- 使用org.springframework.core的程序包
  程序包 | 说明
  --- | ---
  org.springframework.core | Provides basic classes for exception handling and version detection, and other core helpers that are not specific to any part of the framework.
  org.springframework.core.annotation | Core support package for annotations, meta-annotations, and composed annotations with attribute overrides.
  org.springframework.core.codec | `Encoder` and `Decoder` abstractions to convert between a reactive stream of bytes and Java objects.
  org.springframework.core.convert | Type conversion system API.
  org.springframework.core.serializer.support | Support classes for Spring's serializer abstraction.

- org.springframework.core使用的org.springframework.core中的类
  类和说明
  AliasRegistry Common interface for managing aliases.
  AttributeAccessor Interface defining a generic contract for attaching and accessing metadata to/from arbitrary objects.
  Constants.ConstantException Exception thrown when the `Constants` class is asked for an invalid constant name.
  DecoratingClassLoader Base class for decorating ClassLoaders such as `OverridingClassLoader` and `org.springframework.instrument.classloading.ShadowingClassLoader`, providing common handling of excluded packages and classes.
  MethodClassKey A common key class for a method against a specific target class, including `MethodClassKey.toString()` representation and `Comparable` support (as suggested for custom `HashMap` keys as of Java 8).
  MethodIntrospector.MetadataLookup A callback interface for metadata lookup on a given method.
  MethodParameter Helper class that encapsulates the specification of a method parameter, i.e. a `Method` or `Constructor` plus a parameter index and a nested type index for a declared generic type.
  OrderComparator `Comparator` implementation for `Ordered` objects, sorting by order value ascending, respectively by priority descending.
  OrderComparator.OrderSourceProvider Strategy interface to provide an order source for a given object.
  Ordered `Ordered` is an interface that can be implemented by objects that should be orderable, for example in a `Collection`.
  ParameterizedTypeReference The purpose of this class is to enable capturing and passing a generic `Type`.
  ParameterNameDiscoverer Interface to discover parameter names for methods and constructors.
  PrioritizedParameterNameDiscoverer `ParameterNameDiscoverer` implementation that tries several discoverer delegates in succession.
  ReactiveAdapter Adapter for a Reactive Streams `Publisher` to and from an async/reactive type such as `CompletableFuture`, RxJava `Observable`, and others.
  ReactiveAdapterRegistry A registry of adapters to adapt Reactive Streams `Publisher` to/from various async/reactive types such as `CompletableFuture`, RxJava `Observable`, and others.
  ReactiveTypeDescriptor Describes the semantics of a reactive type including boolean checks for `ReactiveTypeDescriptor.isMultiValue()`, `ReactiveTypeDescriptor.isNoValue()`, and `ReactiveTypeDescriptor.supportsEmpty()`.
  ResolvableType Encapsulates a Java `Type`, providing access to `supertypes`, `interfaces`, and `generic parameters` along with the ability to ultimately `resolve` to a `Class`.

- org.springframework.core.annotation使用的org.springframework.core中的类
  类和说明
  MethodParameter Helper class that encapsulates the specification of a method parameter, i.e. a `Method` or `Constructor` plus a parameter index and a nested type index for a declared generic type.
  NestedRuntimeException Handy class for wrapping runtime `Exceptions` with a root cause.
  OrderComparator `Comparator` implementation for `Ordered` objects, sorting by order value ascending, respectively by priority descending.

- org.springframework.core.codec使用的org.springframework.core中的类
  类和说明
  NestedRuntimeException Handy class for wrapping runtime `Exceptions` with a root cause.
  ResolvableType Encapsulates a Java `Type`, providing access to `supertypes`, `interfaces`, and `generic parameters` along with the ability to ultimately `resolve` to a `Class`.

- org.springframework.core.convert使用的org.springframework.core中的类
  类和说明
  MethodParameter Helper class that encapsulates the specification of a method parameter, i.e. a `Method` or `Constructor` plus a parameter index and a nested type index for a declared generic type.
  NestedRuntimeException Handy class for wrapping runtime `Exceptions` with a root cause.
  ResolvableType Encapsulates a Java `Type`, providing access to `supertypes`, `interfaces`, and `generic parameters` along with the ability to ultimately `resolve` to a `Class`.

- org.springframework.core.serializer.support使用的org.springframework.core中的类
  类和说明
  NestedRuntimeException Handy class for wrapping runtime `Exceptions` with a root cause.