标签：framework runtime ble 目的 path gap obj cat dha
public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
this.resourceLoader = resourceLoader;
Assert.notNull(primarySources, "PrimarySources must not be null");
this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
//（1）.根据classpath中的存在的类推断应用类型
this.webApplicationType = WebApplicationType.deduceFromClasspath();
//（2）.获取ApplicationContextInitializer，并设置到Initializers中
setInitializers((Collection) getSpringFactoriesInstances(
ApplicationContextInitializer.class));
//（3）.获取ApplicationContextInitializer，并设置到Initializers中
setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
//（4）.推断主类
this.mainApplicationClass = deduceMainApplicationClass();
}
(1).推断应用类型
this.webApplicationType = WebApplicationType.deduceFromClasspath();
static WebApplicationType deduceFromClasspath() {
//springframework.web.reactive.DispatcherHandler类 if (ClassUtils.isPresent(WEBFLUX_INDICATOR_CLASS, null)
&& !ClassUtils.isPresent(WEBMVC_INDICATOR_CLASS, null)
&& !ClassUtils.isPresent(JERSEY_INDICATOR_CLASS, null)) {
return WebApplicationType.REACTIVE;
}
//不存在javax.servlet.Servlet和org.springframework.web.context.ConfigurableWebApplicationContext
//返回WebApplicationType.NONE
for (String className : SERVLET_INDICATOR_CLASSES) {
if (!ClassUtils.isPresent(className, null)) {
return WebApplicationType.NONE;
}
}
return WebApplicationType.SERVLET;
}
static WebApplicationType deduceFromClasspath() {
//springframework.web.reactive.DispatcherHandler类
//但是不存在org.springframework.web.servlet.DispatcherServlet和org.glassfish.jersey.servlet.ServletContainer类
//返回WebApplicationType.REACTIVE类型
if (ClassUtils.isPresent(WEBFLUX_INDICATOR_CLASS, null)
&& !ClassUtils.isPresent(WEBMVC_INDICATOR_CLASS, null)
&& !ClassUtils.isPresent(JERSEY_INDICATOR_CLASS, null))
{
return WebApplicationType.REACTIVE;
}
//不存在javax.servlet.Servlet和org.springframework.web.context.ConfigurableWebApplicationContext
//返回WebApplicationType.NONE
for (String className : SERVLET_INDICATOR_CLASSES)
{
if (!ClassUtils.isPresent(className, null))
{
return WebApplicationType.NONE;
}
}
//否则返回WebApplicationType.SERVLET
return WebApplicationType.SERVLET;
}
(2)设置Initializers
setInitializers((Collection) getSpringFactoriesInstances( ApplicationContextInitializer.class));
private <T> Collection<T> getSpringFactoriesInstances(Class<T> type) {
return getSpringFactoriesInstances(type, new Class<?>[] {});
}
private <T> Collection<T> getSpringFactoriesInstances(Class<T> type,
Class<?>[] parameterTypes, Object... args) {
ClassLoader classLoader = getClassLoader();
// Use names and ensure unique to protect against duplicates
Set<String> names = new LinkedHashSet<>(
SpringFactoriesLoader.loadFactoryNames(type, classLoader));
List<T> instances = createSpringFactoriesInstances(type, parameterTypes,
classLoader, args, names);
AnnotationAwareOrderComparator.sort(instances);
return instances;
}
setInitializers((Collection) getSpringFactoriesInstances( //(2).初始ApplicationContextInitializer
ApplicationContextInitializer.class));
setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class)); //(3).确定ApplicationListener
this.mainApplicationClass = deduceMainApplicationClass(); //(4).确定mainApplicationClass
(1).推断应用类型，依据判断classPath是否存在
this.webApplicationType = WebApplicationType.deduceFromClasspath();
(2).确定ApplicationContextInitializer,目的待定,重点是读取classpath下的META-INF/spring.factories,并缓存
setInitializers((Collection) getSpringFactoriesInstances(
ApplicationContextInitializer.class));
(3).确定ApplicationListener,目的待定,重点是读取classpath下的META-INF/spring.factories,并缓存
setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
(4).确定mainApplicationClass,重点new RuntimeException().getStackTrace()可以获取堆栈
this.mainApplicationClass = deduceMainApplicationClass();
springboot启动逻辑分析一-------new SpringApplication()
标签：framework runtime ble 目的 path gap obj cat dha
原文地址：https://www.cnblogs.com/itivy/p/11665758.html
