java 接口可以多继承-蒲公英云

java 接口可以多继承

叁歲伎倆 2022-08-01 00:28 354阅读 0赞

接口是常量值和方法定义的集合。接口是一种特殊的抽象类。

java类是单继承的。classB Extends classA

java接口可以多继承。Interface3 Extends Interface0, Interface1, interface……

以下是spring ApplicationContext 接口的代码，同时继承了多个接口

public interface ApplicationContext extends EnvironmentCapable, ListableBeanFactory, HierarchicalBeanFactory,
        MessageSource, ApplicationEventPublisher, ResourcePatternResolver {
    /**
     * Return the unique id of this application context.
     * @return the unique id of the context, or {@code null} if none
     */
    String getId();
    /**
     * Return a name for the deployed application that this context belongs to.
     * @return a name for the deployed application, or the empty String by default
     */
    String getApplicationName();
    /**
     * Return a friendly name for this context.
     * @return a display name for this context (never {@code null})
     */
    String getDisplayName();
    /**
     * Return the timestamp when this context was first loaded.
     * @return the timestamp (ms) when this context was first loaded
     */
    long getStartupDate();
    /**
     * Return the parent context, or {@code null} if there is no parent
     * and this is the root of the context hierarchy.
     * @return the parent context, or {@code null} if there is no parent
     */
    ApplicationContext getParent();
    /**
     * Expose AutowireCapableBeanFactory functionality for this context.
     * <p>This is not typically used by application code, except for the purpose of
     * initializing bean instances that live outside of the application context,
     * applying the Spring bean lifecycle (fully or partly) to them.
     * <p>Alternatively, the internal BeanFactory exposed by the
     * {@link ConfigurableApplicationContext} interface offers access to the
     * {@link AutowireCapableBeanFactory} interface too. The present method mainly
     * serves as a convenient, specific facility on the ApplicationContext interface.
     * <p><b>NOTE: As of 4.2, this method will consistently throw IllegalStateException
     * after the application context has been closed.</b> In current Spring Framework
     * versions, only refreshable application contexts behave that way; as of 4.2,
     * all application context implementations will be required to comply.
     * @return the AutowireCapableBeanFactory for this context
     * @throws IllegalStateException if the context does not support the
     * {@link AutowireCapableBeanFactory} interface, or does not hold an
     * autowire-capable bean factory yet (e.g. if {@code refresh()} has
     * never been called), or if the context has been closed already
     * @see ConfigurableApplicationContext#refresh()
     * @see ConfigurableApplicationContext#getBeanFactory()
     */
    AutowireCapableBeanFactory getAutowireCapableBeanFactory() throws IllegalStateException;
}