ClassPathXmlApplicationContext构造器的前两个方法调用部分注释

Author: WithoutCause

spring-context/src/main/java/org/springframework/context/support/AbstractApplicationContext.java

@@ -215,6 +215,9 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	@Nullable
 	private Thread shutdownHook;
 
+	/*
+	 * 在 new 容器的时候，会将该资源初始化
+	 */
 	/** ResourcePatternResolver used by this context. */
 	private ResourcePatternResolver resourcePatternResolver;
 
@@ -249,7 +252,7 @@ public abstract class AbstractApplicationContext extends DefaultResourceLoader
 	 * Create a new AbstractApplicationContext with no parent.
 	 */
 	public AbstractApplicationContext() {
-		this.resourcePatternResolver = getResourcePatternResolver();
+		this.resourcePatternResolver = getResourcePatternResolver(); // 获取资源解析器
 	}
 
 	/**
@@ -258,7 +261,7 @@ public AbstractApplicationContext() {
 	 */
 	public AbstractApplicationContext(@Nullable ApplicationContext parent) {
 		this();
-		setParent(parent);
+		setParent(parent); // parent 默认为 null, 设置当前的 parent 参数为 null
 	}
 
 
@@ -489,7 +492,7 @@ LifecycleProcessor getLifecycleProcessor() throws IllegalStateException {
 	 * @see org.springframework.core.io.support.PathMatchingResourcePatternResolver
 	 */
 	protected ResourcePatternResolver getResourcePatternResolver() {
-		return new PathMatchingResourcePatternResolver(this);
+		return new PathMatchingResourcePatternResolver(this); // 该解析器支持 Ant 风格，简单的 url 协议。例如：file:// 这种也可以解析。 同时传入 resourceLoader
 	}
 
 

spring-context/src/main/java/org/springframework/context/support/AbstractRefreshableConfigApplicationContext.java

@@ -70,6 +70,7 @@ public void setConfigLocation(String location) {
 	}
 
 	/**
+	 * @param locations 传入参数类型： classpath:/applicationContext.xml
 	 * Set the config locations for this application context.
 	 * <p>If not set, the implementation may use a default as appropriate.
 	 */
@@ -78,7 +79,7 @@ public void setConfigLocations(@Nullable String... locations) {
 			Assert.noNullElements(locations, "Config locations must not be null");
 			this.configLocations = new String[locations.length];
 			for (int i = 0; i < locations.length; i++) {
-				this.configLocations[i] = resolvePath(locations[i]).trim();
+				this.configLocations[i] = resolvePath(locations[i]).trim(); // 如果传入的是多个路径，向数组中添加值。
 			}
 		}
 		else {
@@ -122,7 +123,7 @@ protected String[] getDefaultConfigLocations() {
 	 * @see org.springframework.core.env.Environment#resolveRequiredPlaceholders(String)
 	 */
 	protected String resolvePath(String path) {
-		return getEnvironment().resolveRequiredPlaceholders(path);
+		return getEnvironment().resolveRequiredPlaceholders(path); // 解析占位符 ${}
 	}
 
 

spring-context/src/main/java/org/springframework/context/support/ClassPathXmlApplicationContext.java

@@ -76,6 +76,8 @@ public ClassPathXmlApplicationContext(ApplicationContext parent) {
 	}
 
 	/**
+	 * 我们手动创建容器一般会使用该方法，将传入一个 xml 文件的路径。
+	 *
 	 * Create a new ClassPathXmlApplicationContext, loading the definitions
 	 * from the given XML file and automatically refreshing the context.
 	 * @param configLocation resource location
@@ -124,6 +126,11 @@ public ClassPathXmlApplicationContext(String[] configLocations, boolean refresh)
 	}
 
 	/**
+	 * 真正执行的构造器方法，
+	 * configLocations：传入的 xml 文件路径，可以传入多个。
+	 * refresh:是否刷新容器，默认是 true
+	 * parent: 父容器
+	 *
 	 * Create a new ClassPathXmlApplicationContext with the given parent,
 	 * loading the definitions from the given XML files.
 	 * @param configLocations array of resource locations
@@ -138,10 +145,10 @@ public ClassPathXmlApplicationContext(
 			String[] configLocations, boolean refresh, @Nullable ApplicationContext parent)
 			throws BeansException {
 
-		super(parent);
-		setConfigLocations(configLocations);
+		super(parent);  // 调用一系列父类的构造器，最终调到 AbstractApplicationContext 的构造器
+		setConfigLocations(configLocations);  // 设置 xml 文件的路径
 		if (refresh) {
-			refresh();
+			refresh(); // 刷新容器
 		}
 	}