自定义starter

Author: 曾梓健

myTest/pom.xml

@@ -27,6 +27,12 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+
+		<dependency>
+			<groupId>com.hand</groupId>
+			<artifactId>zzj-spring-boot-stater</artifactId>
+			<version>1.0-SNAPSHOT</version>
+		</dependency>
 	</dependencies>
 
 	<build>

myTest/src/main/resources/application-prod.properties

@@ -0,0 +1 @@
+server.port=8082

myTest/src/main/resources/application.properties

@@ -1 +1,4 @@
+server.port=8081
 
+simplebean.id=1
+simplebean.name=zzj

myTest/src/test/java/com/hand/mytest/MyTestApplicationTests.java

@@ -1,13 +1,22 @@
 package com.hand.mytest;
 
+import com.hand.pojo.SimpleBean;
 import org.junit.jupiter.api.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
 
+@RunWith(SpringRunner.class)
 @SpringBootTest
 class MyTestApplicationTests {
 
+	@Autowired
+	private SimpleBean simpleBean;
+
 	@Test
 	void contextLoads() {
+		System.out.println(simpleBean);
 	}
 
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/BeanDefinitionLoader.java

@@ -79,7 +79,9 @@ class BeanDefinitionLoader {
 		Assert.notNull(registry, "Registry must not be null");
 		Assert.notEmpty(sources, "Sources must not be empty");
 		this.sources = sources;
+		// 注解形式的bean定义读取器,比如: 读取 @Configuration @Bean @Component @Controller 等等
 		this.annotatedReader = new AnnotatedBeanDefinitionReader(registry);
+		// xml形式的bean定义读取器
 		this.xmlReader = new XmlBeanDefinitionReader(registry);
 		if (isGroovyPresent()) {
 			this.groovyReader = new GroovyBeanDefinitionReader(registry);
@@ -132,7 +134,9 @@ int load() {
 
 	private int load(Object source) {
 		Assert.notNull(source, "Source must not be null");
+		// source是主类: run方法的主类
 		if (source instanceof Class<?>) {
+			// 从Class加载
 			return load((Class<?>) source);
 		}
 		if (source instanceof Resource) {
@@ -149,11 +153,14 @@ private int load(Object source) {
 
 	private int load(Class<?> source) {
 		if (isGroovyPresent() && GroovyBeanDefinitionSource.class.isAssignableFrom(source)) {
+			// 这个条件不满足,不会执行
 			// Any GroovyLoaders added in beans{} DSL can contribute beans here
 			GroovyBeanDefinitionSource loader = BeanUtils.instantiateClass(source, GroovyBeanDefinitionSource.class);
 			load(loader);
 		}
+		// 判断主类是否有标注@Component注解
 		if (isComponent(source)) {
+			// 将启动类的beanDefinition注册进beanDefinitionMap
 			this.annotatedReader.register(source);
 			return 1;
 		}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/SpringApplication.java

@@ -179,7 +179,7 @@ public class SpringApplication {
 	 * environments.
 	 */
 	public static final String DEFAULT_REACTIVE_WEB_CONTEXT_CLASS = "org.springframework."
-			+ "boot.web.reactive.context.AnnotationConfigReactiveWebServerApplicationContext";
+			+ "boot.web.reactive.context .AnnotationConfigReactiveWebServerApplicationContext";
 
 	/**
 	 * Default banner location.
@@ -265,12 +265,17 @@ public SpringApplication(Class<?>... primarySources) {
 	 */
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	public SpringApplication(ResourceLoader resourceLoader, Class<?>... primarySources) {
+		// 设置资源加载器为null
 		this.resourceLoader = resourceLoader;
 		Assert.notNull(primarySources, "PrimarySources must not be null");
 		this.primarySources = new LinkedHashSet<>(Arrays.asList(primarySources));
+		// 1.推断应用类型,后面会根据类型初始化对应的环境,常用的一般都是servlet环境
 		this.webApplicationType = WebApplicationType.deduceFromClasspath();
+		// 2.根据ApplicationContextInitializer为key从classPath 下spring.factories配置文件中获取实例化的类
 		setInitializers((Collection) getSpringFactoriesInstances(ApplicationContextInitializer.class));
+		// 3.根据ApplicationListener为key从从classPath下spring.factories配置文件中获取实例化的类
 		setListeners((Collection) getSpringFactoriesInstances(ApplicationListener.class));
+		// 4.根据调用栈,推断出main方法的类名
 		this.mainApplicationClass = deduceMainApplicationClass();
 	}
 
@@ -296,24 +301,34 @@ private Class<?> deduceMainApplicationClass() {
 	 * @return a running {@link ApplicationContext}
 	 */
 	public ConfigurableApplicationContext run(String... args) {
+		// 记录程序运行时间
 		StopWatch stopWatch = new StopWatch();
 		stopWatch.start();
+		// ConfigurableApplicationContext接口 继承了 ApplicationContext接口,在ApplicationContext基础上增加了配置上下文的工具
 		ConfigurableApplicationContext context = null;
 		Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>();
 		configureHeadlessProperty();
+		// 1.获取并启动监听器
 		SpringApplicationRunListeners listeners = getRunListeners(args);
 		listeners.starting();
 		try {
 			ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
+			// 2.构造应用上下文环境
 			ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);
 			configureIgnoreBeanInfo(environment);
 			Banner printedBanner = printBanner(environment);
+			// 3.初始化应用上下文
 			context = createApplicationContext();
+			// 实例化SpringBootExceptionReporter,用来支持报告关于启动的错误
 			exceptionReporters = getSpringFactoriesInstances(SpringBootExceptionReporter.class,
 					new Class[] { ConfigurableApplicationContext.class }, context);
+			// 4.刷新应用上下文的准备工作
 			prepareContext(context, environment, listeners, applicationArguments, printedBanner);
+			// 5.刷新应用上下文
 			refreshContext(context);
+			// 6.刷新应用上下文的扩展接口
 			afterRefresh(context, applicationArguments);
+			// 时间记录停止
 			stopWatch.stop();
 			if (this.logStartupInfo) {
 				new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
@@ -339,9 +354,12 @@ public ConfigurableApplicationContext run(String... args) {
 	private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
 			ApplicationArguments applicationArguments) {
 		// Create and configure the environment
+		// 创建并配置相应的环境
 		ConfigurableEnvironment environment = getOrCreateEnvironment();
+		// 根据用户配置,配置environment系统环境
 		configureEnvironment(environment, applicationArguments.getSourceArgs());
 		ConfigurationPropertySources.attach(environment);
+		// 启动相应的监听器,其中重要的一个监听器就是 configFileApplicationListener,就是加载项目配置文件的监听器
 		listeners.environmentPrepared(environment);
 		bindToSpringApplication(environment);
 		if (!this.isCustomEnvironment) {
@@ -365,20 +383,26 @@ private Class<? extends StandardEnvironment> deduceEnvironmentClass() {
 
 	private void prepareContext(ConfigurableApplicationContext context, ConfigurableEnvironment environment,
 			SpringApplicationRunListeners listeners, ApplicationArguments applicationArguments, Banner printedBanner) {
+		// 设置容器环境
 		context.setEnvironment(environment);
+		// 执行容器后置处理
 		postProcessApplicationContext(context);
 		applyInitializers(context);
+		// 向各个监听器发送容器已经准备好的事件
 		listeners.contextPrepared(context);
 		if (this.logStartupInfo) {
 			logStartupInfo(context.getParent() == null);
 			logStartupProfileInfo(context);
 		}
 		// Add boot specific singleton beans
+		// 拿到容器对象
 		ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();
 		beanFactory.registerSingleton("springApplicationArguments", applicationArguments);
 		if (printedBanner != null) {
+			// 将 printedBanner 也封装成单例,注册进容器
 			beanFactory.registerSingleton("springBootBanner", printedBanner);
 		}
+		// 下面这个条件是符合的
 		if (beanFactory instanceof DefaultListableBeanFactory) {
 			((DefaultListableBeanFactory) beanFactory)
 					.setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);
@@ -389,7 +413,9 @@ private void prepareContext(ConfigurableApplicationContext context, Configurable
 		// Load the sources
 		Set<Object> sources = getAllSources();
 		Assert.notEmpty(sources, "Sources must not be empty");
+		// 加载我们的启动类,将启动类注入容器
 		load(context, sources.toArray(new Object[0]));
+		// 发布容器已加载事件
 		listeners.contextLoaded(context);
 	}
 
@@ -412,6 +438,8 @@ private void configureHeadlessProperty() {
 
 	private SpringApplicationRunListeners getRunListeners(String[] args) {
 		Class<?>[] types = new Class<?>[] { SpringApplication.class, String[].class };
+		// SpringApplicationRunListener 负责在springboot启动的不同阶段广播出不同的消息,传递给ApplicationListener监听器实现类
+		// org.springframework.boot.context.event.EventPublishingRunListener 就这一个实例
 		return new SpringApplicationRunListeners(logger,
 				getSpringFactoriesInstances(SpringApplicationRunListener.class, types, this, args));
 	}
@@ -423,8 +451,12 @@ private <T> Collection<T> getSpringFactoriesInstances(Class<T> type) {
 	private <T> Collection<T> getSpringFactoriesInstances(Class<T> type, Class<?>[] parameterTypes, Object... args) {
 		ClassLoader classLoader = getClassLoader();
 		// Use names and ensure unique to protect against duplicates
+		// 通过指定的classLoader从MEATA-INF/spring.factories 中读取key为 type.getName()的value
+		// 一共有七个
 		Set<String> names = new LinkedHashSet<>(SpringFactoriesLoader.loadFactoryNames(type, classLoader));
+		// 创建七个spring工厂实例
 		List<T> instances = createSpringFactoriesInstances(type, parameterTypes, classLoader, args, names);
+		// 对七个spring工厂实例排序()
 		AnnotationAwareOrderComparator.sort(instances);
 		return instances;
 	}
@@ -435,6 +467,7 @@ private <T> List<T> createSpringFactoriesInstances(Class<T> type, Class<?>[] par
 		List<T> instances = new ArrayList<>(names.size());
 		for (String name : names) {
 			try {
+				// 根据全路径名实例化
 				Class<?> instanceClass = ClassUtils.forName(name, classLoader);
 				Assert.isAssignable(type, instanceClass);
 				Constructor<?> constructor = instanceClass.getDeclaredConstructor(parameterTypes);
@@ -454,6 +487,7 @@ private ConfigurableEnvironment getOrCreateEnvironment() {
 		}
 		switch (this.webApplicationType) {
 		case SERVLET:
+			// 该应用如果是servlet类型的应用,走这里的逻辑
 			return new StandardServletEnvironment();
 		case REACTIVE:
 			return new StandardReactiveWebEnvironment();
@@ -478,7 +512,9 @@ protected void configureEnvironment(ConfigurableEnvironment environment, String[
 			ConversionService conversionService = ApplicationConversionService.getSharedInstance();
 			environment.setConversionService((ConfigurableConversionService) conversionService);
 		}
+		// 将main函数的args封装成 SimpleCommandLinePropertySource加入环境中
 		configurePropertySources(environment, args);
+		// 激活相应的配置文件
 		configureProfiles(environment, args);
 	}
 
@@ -678,6 +714,7 @@ protected void load(ApplicationContext context, Object[] sources) {
 		if (logger.isDebugEnabled()) {
 			logger.debug("Loading source " + StringUtils.arrayToCommaDelimitedString(sources));
 		}
+		// 创建BeanDefinitionLoader   创建了注解形式的bean定义读取器
 		BeanDefinitionLoader loader = createBeanDefinitionLoader(getBeanDefinitionRegistry(context), sources);
 		if (this.beanNameGenerator != null) {
 			loader.setBeanNameGenerator(this.beanNameGenerator);
@@ -1212,6 +1249,7 @@ public Set<ApplicationListener<?>> getListeners() {
 	 * @return the running {@link ApplicationContext}
 	 */
 	public static ConfigurableApplicationContext run(Class<?> primarySource, String... args) {
+		// 调用重载方法
 		return run(new Class<?>[] { primarySource }, args);
 	}
 
@@ -1223,6 +1261,7 @@ public static ConfigurableApplicationContext run(Class<?> primarySource, String.
 	 * @return the running {@link ApplicationContext}
 	 */
 	public static ConfigurableApplicationContext run(Class<?>[] primarySources, String[] args) {
+		// 两件事:初始化SpringApplication,然后调用run方法
 		return new SpringApplication(primarySources).run(args);
 	}
 

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/WebApplicationType.java

@@ -68,6 +68,7 @@ static WebApplicationType deduceFromClasspath() {
 				return WebApplicationType.NONE;
 			}
 		}
+		// 走这里
 		return WebApplicationType.SERVLET;
 	}
 

zzj-spring-boot-stater/pom.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+		 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<groupId>com.hand</groupId>
+	<artifactId>zzj-spring-boot-stater</artifactId>
+	<version>1.0-SNAPSHOT</version>
+
+	<properties>
+		<maven.compiler.source>8</maven.compiler.source>
+		<maven.compiler.target>8</maven.compiler.target>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-autoconfigure</artifactId>
+			<version>2.2.9.RELEASE</version>
+		</dependency>
+	</dependencies>
+
+</project>

zzj-spring-boot-stater/src/main/java/com/hand/config/MyAutoConfiguration.java

@@ -0,0 +1,23 @@
+package com.hand.config;
+
+import com.hand.pojo.SimpleBean;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author zijian.zeng@hand-china.com
+ * @since 2023-01-27
+ */
+@Configuration
+public class MyAutoConfiguration {
+
+	static {
+		System.out.println("MyAutoConfiguration init...");
+	}
+
+	@Bean
+	public SimpleBean simpleBean() {
+		return new SimpleBean();
+	}
+
+}

zzj-spring-boot-stater/src/main/java/com/hand/pojo/SimpleBean.java

@@ -0,0 +1,41 @@
+package com.hand.pojo;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * @author zijian.zeng@hand-china.com
+ * @since 2023-01-27
+ */
+@EnableConfigurationProperties
+@ConfigurationProperties(prefix = "simplebean")
+public class SimpleBean {
+
+	private int id;
+	private String name;
+
+	public int getId() {
+		return id;
+	}
+
+	public void setId(int id) {
+		this.id = id;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	@Override
+	public String toString() {
+		return "SimpleBean{" +
+				"id=" + id +
+				", name='" + name + '\'' +
+				'}';
+	}
+}

zzj-spring-boot-stater/src/main/resources/META-INF/spring.factories

@@ -0,0 +1 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.hand.config.MyAutoConfiguration