Spring 中context.start作用

时间:2024-08-05 09:35:20

我们经常会看到 如下代码

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(configPath.split("[,\\s]+"));
context.start();

其实该context.start()的作用就是初始话配置文件中的bean对象

    //---------------------------------------------------------------------
// Implementation of Lifecycle interface
//--------------------------------------------------------------------- public void start() {
Map lifecycleBeans = getLifecycleBeans();
for (Iterator it = new LinkedHashSet(lifecycleBeans.keySet()).iterator(); it.hasNext();) {
String beanName = (String) it.next();
doStart(lifecycleBeans, beanName);
}
publishEvent(new ContextStartedEvent(this));
} /**
* Start the specified bean as part of the given set of Lifecycle beans,
* making sure that any beans that it depends on are started first.
* @param lifecycleBeans Map with bean name as key and Lifecycle instance as value
* @param beanName the name of the bean to start
*/
private void doStart(Map lifecycleBeans, String beanName) {
Lifecycle bean = (Lifecycle) lifecycleBeans.get(beanName);
if (bean != null) {
String[] dependenciesForBean = getBeanFactory().getDependenciesForBean(beanName); //找到依赖的类
for (int i = 0; i < dependenciesForBean.length; i++) {
doStart(lifecycleBeans, dependenciesForBean[i]);//递归调用找到依赖的类
}
if (!bean.isRunning()) {
bean.start();
}
lifecycleBeans.remove(beanName);
}
}