[笔记]深入剖析Tomcat－生命周期,日志记录器

lifecycle接口

实现lifecycle接口的组件启动或关闭时可以触发before_start_event, start_event...stop_event...事件，管理生命周期

public interface Lifecycle{
public void addLifecycleListener(LifecycleListener listener);
public LifecycleListener[] findLifecycleListener();
public void removeLifecycleListener(LifecycleListener listener);
public void start();
public void stop();
}

LifecycleEvent

public final class LifecycleEvent extends EventObject{
private Object data= null;
private Lifecycle lifecycle = null;
private String type = null;
//...
public LifecycleEvent(Lifecycle lifecycle, String type, Object data){
...
}
}

LifecycleListener

public interface LifecycleListener{
public ovid lifecycleEvent(LifecycleEvent event);//触发event事件
}

LifecycleSupport，实现了Lifecycle接口，将所有注册的事件监听器存储到一个数组中，帮助组件管理监听器，并触发相应的生命周期

public final class LifecycleSupport{
private Lifecycle lifecycle = null;
private LifecycleListener[] listeners = new LifecycleListener[0];

public LifecycleSupport(Lifecycle lifecycle){
//...
}
public void addLifecycleListener(LifecycleListener listener){
//add listener to listeners
}
//findLifecycleListenres()
//removeLifecycleListener
public void fireLifecycleEvent(String type, Object data){
LifecycleEvent event = new LifecycleEvent(lifecycle, type, data);
//trigger listeners lifecycleEvent method
}
}

public class SimpleContext implements Context, Container, Lifecycle{
//...
protected LifecycleSupport = new LifecycleSupport(this);
public synchronized void start{
if (started){
started = true;
lifecycle.fireLifycycleEvent(BEFORE_START_EVENT, null);
if(loader instanceof Lifecycle){
loader.start();
}
if(pipeline instanceof Lifecycle){
pipeline.start();
}
Container[] children = findChidren();
for (Container child : children){
if(child instanceof Lifecycle){
child.start();
}
}
lifecycle.fireLifycycleEvent(START_EVENT, null);
}
lifecycle.fireLifycycleEvent(AFTER_START_EVENT, null);
}
//public void stop as start method
}