差異處
這裏顯示兩個版本的差異處。
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java:log4j:extend_appender [2017/01/22 15:53] tony [How to?] |
java:log4j:extend_appender [2023/06/25 09:48] |
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| - | {{tag>java log4j}} | ||
| - | ====== Extend the appender (Working) ====== | ||
| - | ===== Problem ===== | ||
| - | 我替老婆做了某個遊戲外掛，然後我希望能把log內容顯示在畫面上，例如:\\ | ||
| - | {{:java:log4j:log4j_extend_appender_result.png|}}\\ | ||
| - | 我想透過log4j去通知畫面更新而不是再另開一個api；本篇文章主要告訴大家extend log4j appender的方法去達到這個目的。 | ||
| - | ===== How to? ===== | ||
| - | 原先我的Subject是目前工作的狀態，負責通知的是工作的controller；而Observer則是UI，實作以下介面，Subject有變動會通知它: | ||
| - | <code java> | ||
| - | public interface IStateChangedListener { | ||
| - | void update(Object[] messages); | ||
| - | } | ||
| - | |||
| - | public class MessageTable extends JTable implements IStateChangedListener { | ||
| - | // skip | ||
| - | } | ||
| - | </code> | ||
| - | 修改後，Subject為extend的appender，要做這些事情: | ||
| - | - Extend AppenderSkeleton。 | ||
| - | - 負責Observer的註冊與通知。 | ||
| - | <code java> | ||
| - | public class NotificationAppender extends AppenderSkeleton { | ||
| - | |||
| - | protected static List<IStateChangedListener> mStateChangedListenerList = new ArrayList<>(); | ||
| - | |||
| - | private static NotificationAppender mInstance = new NotificationAppender(); | ||
| - | |||
| - | public static NotificationAppender getInstance(){ | ||
| - | return mInstance; | ||
| - | } | ||
| - | |||
| - | @Override | ||
| - | protected void append(LoggingEvent arg0) { | ||
| - | notify(arg0.getLevel().toString(), arg0.getMessage().toString()); | ||
| - | } | ||
| - | |||
| - | public void addListener(IStateChangedListener aListener){ | ||
| - | mStateChangedListenerList.add(aListener); | ||
| - | } | ||
| - | |||
| - | private static String getTimeString(Date aDate){ | ||
| - | DateFormat df = new SimpleDateFormat("HH:mm:ss"); | ||
| - | return df.format(aDate); | ||
| - | } | ||
| - | |||
| - | protected void notify(String aState, String aMessage){ | ||
| - | Date now = new Date(); | ||
| - | for( IStateChangedListener listener : mStateChangedListenerList){ | ||
| - | listener.update(new Object[]{ | ||
| - | getTimeString(now), aState, aMessage | ||
| - | }); | ||
| - | } | ||
| - | } | ||
| - | |||
| - | @Override | ||
| - | public void close() { | ||
| - | |||
| - | } | ||
| - | |||
| - | @Override | ||
| - | public boolean requiresLayout() { | ||
| - | return false; | ||
| - | } | ||
| - | } | ||
| - | </code> | ||
| - | 在config的部分如下，我針對某兩個類別將訊息送至MessageTable UI: | ||
| - | <code java> | ||
| - | log4j.additivity.org.tonylin.bot.fantasycity.RunBotJob=false | ||
| - | log4j.logger.org.tonylin.bot.fantasycity.RunBotJob=DEBUG, CONSOLE, LOGFILE, MESSAGETABBLE | ||
| - | |||
| - | log4j.additivity.org.tonylin.bot.fantasycity.BotUtils=false | ||
| - | log4j.logger.org.tonylin.bot.fantasycity.BotUtils=DEBUG, CONSOLE, LOGFILE, MESSAGETABBLE | ||
| - | |||
| - | # MessageTable Logger | ||
| - | log4j.appender.MESSAGETABBLE=org.tonylin.bot.common.NotificationAppender | ||
| - | log4j.appender.CONSOLE.Threshold=DEBUG | ||
| - | </code> | ||
| - | ===== Reference ===== | ||
| - | * [[https://gist.github.com/kengelke/4664612|GitHub - CachingSingletonAppender]] | ||
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