[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
}