聊聊springboot的Customizer

@FunctionalInterface
public interface TaskExecutorCustomizer {

	/**
	 * Callback to customize a {@link ThreadPoolTaskExecutor} instance.
	 * @param taskExecutor the task executor to customize
	 */
	void customize(ThreadPoolTaskExecutor taskExecutor);

}

	@Bean
	@ConditionalOnMissingBean
	public TaskExecutorBuilder taskExecutorBuilder(TaskExecutionProperties properties,
			ObjectProvider<TaskExecutorCustomizer> taskExecutorCustomizers,
			ObjectProvider<TaskDecorator> taskDecorator) {
		TaskExecutionProperties.Pool pool = properties.getPool();
		TaskExecutorBuilder builder = new TaskExecutorBuilder();
		builder = builder.queueCapacity(pool.getQueueCapacity());
		builder = builder.corePoolSize(pool.getCoreSize());
		builder = builder.maxPoolSize(pool.getMaxSize());
		builder = builder.allowCoreThreadTimeOut(pool.isAllowCoreThreadTimeout());
		builder = builder.keepAlive(pool.getKeepAlive());
		Shutdown shutdown = properties.getShutdown();
		builder = builder.awaitTermination(shutdown.isAwaitTermination());
		builder = builder.awaitTerminationPeriod(shutdown.getAwaitTerminationPeriod());
		builder = builder.threadNamePrefix(properties.getThreadNamePrefix());
		builder = builder.customizers(taskExecutorCustomizers.orderedStream()::iterator);
		builder = builder.taskDecorator(taskDecorator.getIfUnique());
		return builder;
	}

	/**
	 * Set the {@link TaskExecutorCustomizer TaskExecutorCustomizers} that should be
	 * applied to the {@link ThreadPoolTaskExecutor}. Customizers are applied in the order
	 * that they were added after builder configuration has been applied. Setting this
	 * value will replace any previously configured customizers.
	 * @param customizers the customizers to set
	 * @return a new builder instance
	 * @see #additionalCustomizers(TaskExecutorCustomizer...)
	 */
	public TaskExecutorBuilder customizers(TaskExecutorCustomizer... customizers) {
		Assert.notNull(customizers, "Customizers must not be null");
		return customizers(Arrays.asList(customizers));
	}	

@FunctionalInterface
public interface TaskSchedulerCustomizer {

	/**
	 * Callback to customize a {@link ThreadPoolTaskScheduler} instance.
	 * @param taskScheduler the task scheduler to customize
	 */
	void customize(ThreadPoolTaskScheduler taskScheduler);

}

	@Bean
	@ConditionalOnMissingBean
	public TaskSchedulerBuilder taskSchedulerBuilder(TaskSchedulingProperties properties,
			ObjectProvider<TaskSchedulerCustomizer> taskSchedulerCustomizers) {
		TaskSchedulerBuilder builder = new TaskSchedulerBuilder();
		builder = builder.poolSize(properties.getPool().getSize());
		Shutdown shutdown = properties.getShutdown();
		builder = builder.awaitTermination(shutdown.isAwaitTermination());
		builder = builder.awaitTerminationPeriod(shutdown.getAwaitTerminationPeriod());
		builder = builder.threadNamePrefix(properties.getThreadNamePrefix());
		builder = builder.customizers(taskSchedulerCustomizers);
		return builder;
	}

	/**
	 * Set the {@link TaskSchedulerCustomizer TaskSchedulerCustomizers} that should be
	 * applied to the {@link ThreadPoolTaskScheduler}. Customizers are applied in the
	 * order that they were added after builder configuration has been applied. Setting
	 * this value will replace any previously configured customizers.
	 * @param customizers the customizers to set
	 * @return a new builder instance
	 * @see #additionalCustomizers(TaskSchedulerCustomizer...)
	 */
	public TaskSchedulerBuilder customizers(TaskSchedulerCustomizer... customizers) {
		Assert.notNull(customizers, "Customizers must not be null");
		return customizers(Arrays.asList(customizers));
	}	

@FunctionalInterface
public interface RestTemplateCustomizer {

	/**
	 * Callback to customize a {@link RestTemplate} instance.
	 * @param restTemplate the template to customize
	 */
	void customize(RestTemplate restTemplate);

}

	@Bean
	@Lazy
	@ConditionalOnMissingBean
	public RestTemplateBuilderConfigurer restTemplateBuilderConfigurer(
			ObjectProvider<HttpMessageConverters> messageConverters,
			ObjectProvider<RestTemplateCustomizer> restTemplateCustomizers,
			ObjectProvider<RestTemplateRequestCustomizer<?>> restTemplateRequestCustomizers) {
		RestTemplateBuilderConfigurer configurer = new RestTemplateBuilderConfigurer();
		configurer.setHttpMessageConverters(messageConverters.getIfUnique());
		configurer.setRestTemplateCustomizers(restTemplateCustomizers.orderedStream().collect(Collectors.toList()));
		configurer.setRestTemplateRequestCustomizers(
				restTemplateRequestCustomizers.orderedStream().collect(Collectors.toList()));
		return configurer;
	}