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本文主要研究一下logback的ShutdownHook
ShutdownHook
ch/qos/logback/core/hook/ShutdownHook.java
代码语言：javascript复制/**
* Interface describing a logback shutdown hook implementation
*
* @author Mike Reinhold
*/
public interface ShutdownHook extends Runnable, ContextAware {
}ShutdownHook接口继承了Runnable、ContextAware接口
ShutdownHookBase
ch/qos/logback/core/hook/ShutdownHookBase.java
代码语言：javascript复制/**
* Base class for classes implementing a Logback ShutdownHook via extension
*
* @author Mike Reinhold
*/
public abstract class ShutdownHookBase extends ContextAwareBase implements ShutdownHook {
public ShutdownHookBase() {
}
/**
* Default method for stopping the Logback context
*/
protected void stop() {
addInfo("Logback context being closed via shutdown hook");
Context hookContext = getContext();
if (hookContext instanceof ContextBase) {
ContextBase context = (ContextBase) hookContext;
context.stop();
}
}
}ShutdownHookBase继承了ContextAwareBase，声明实现ShutdownHook，它提供了一个stop方法，用于关闭ContextBase
DelayingShutdownHook
ch/qos/logback/core/hook/DelayingShutdownHook.java
代码语言：javascript复制/**
* ShutdownHook implementation that stops the Logback context after a specified
* delay. The default delay is 0 ms (zero).
*
* @author Mike Reinhold
*/
public class DelayingShutdownHook extends ShutdownHookBase {
/**
* The default is no delay before shutdown.
*/
public static final Duration DEFAULT_DELAY = Duration.buildByMilliseconds(0);
/**
* The delay in milliseconds before the ShutdownHook stops the logback context
*/
private Duration delay = DEFAULT_DELAY;
public DelayingShutdownHook() {
}
public Duration getDelay() {
return delay;
}
/**
* The duration to wait before shutting down the current logback context.
*
* @param delay
*/
public void setDelay(Duration delay) {
this.delay = delay;
}
public void run() {
addInfo("Sleeping for " delay);
try {
Thread.sleep(delay.getMilliseconds());
} catch (InterruptedException e) {
}
super.stop();
}
}DelayingShutdownHook继承了ShutdownHookBase，其run方法先sleep指定的delay，然后执行stop方法
示例
代码语言：javascript复制<configuration debug="false">
<shutdownHook class="ch.qos.logback.core.hook.DelayingShutdownHook">
<delay>10</delay>
</shutdownHook>
<appender name="A" class="ch.qos.logback.core.read.ListAppender"/>
<root level="DEBUG">
<appender-ref ref="A" />
</root>
</configuration>小结
logback的ShutdownHook接口继承了Runnable、ContextAware接口，它有一个抽象类ShutdownHookBase提供了一个stop方法，用于关闭ContextBase，它的子类为DelayingShutdownHook，可以延迟指定时间再关闭ContextBase。
