② 启动缓慢

启动缓慢分析

当应用中拥有大对象,可能会导致单侧启动比较慢,针对这种问题有不同的解决方案

SpringBoot 2.2 解决方案#

spring.main.lazy-initialization = true

SpringApplication 会自动添加一个叫 LazyInitializationBeanFactoryPostProcessor的处理器

SpringBoot 2.2 以前#

给应用上下文提前装载一个类似的处理器,然后通过 BeanFactoryPostProcessor 在容器刷新前循环将 BeanDefinition 声明懒加载

public class BeanLazyApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        applicationContext.addBeanFactoryPostProcessor(new LazyBeanDefinitionPostProcessor());
    }

    public static class LazyBeanDefinitionPostProcessor implements BeanFactoryPostProcessor, Ordered {

        @Override
        public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
            for (String beanName : beanFactory.getBeanDefinitionNames()) {
                BeanDefinition beanDefinition = beanFactory.getBeanDefinition(beanName);
                if (beanDefinition instanceof AbstractBeanDefinition) {
                    beanDefinition.setLazyInit(true);
                }
            }
        }

        @Override
        public int getOrder() {
            return Ordered.HIGHEST_PRECEDENCE;
        }
    }

}

测试引导类配置变更

@ContextConfiguration 通过容器初始化去新增处理器
@ActiveProfiles 指定测试环境激活的配置是local

@ContextConfiguration添加处理器

@Slf4j
@ActiveProfiles({"local"})
@ContextConfiguration(initializers = {BeanLazyApplicationContextInitializer.class})
// 使用Spring容器引导
@RunWith(SpringRunner.class)
@SpringBootTest(classes = {CenterProviderApplication.class}) // 指定启动类
public class BaseApplicationTest {
    
}

如何确定版本?#

Idea 中搜索 @SpringApplication 查看所在的包