[펌] 파일 감시 데몬 만들기

 

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 출처: http://blog.naver.com/shin7688/120172067214

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1. 중요 라이브러리:

           - java.util.concurrent.ScheduledExecutorService

 

2. 파일 변경 감시 데몬 만들기(WatcherDaemon)

 

<WatcherDaemon class> 

package test.watcher;   import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.net.URL; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit;   public class WatcherDaemon {                       String FILE_ROUTE_CONF_FILE = "watch.txt";            protected static final int DEFAULT_RELOAD_CHECK_INTERVAL_MS = 10000;            protected ScheduledExecutorService watchTimer;            protected String[] absoluteResourcePaths;                       public static void main(String[] args)            {                      WatcherDaemon daemon = new WatcherDaemon();                      daemon.init();            }                       public void init()            {                      URL url = getClass().getClassLoader().getResource(FILE_ROUTE_CONF_FILE);                      absoluteResourcePaths = new String[]{url.getPath()};                      deploy();                      createRedeployMonitor();            }                       protected void createRedeployMonitor()            {                    AbstractFileWatcher watcher = new ConfigFileWatcher(absoluteResourcePaths [0]);                    scheduleConfigMonitor(watcher);            }                       protected void scheduleConfigMonitor(AbstractFileWatcher watcher)            {                   final int reloadIntervalMs = DEFAULT_RELOAD_CHECK_INTERVAL_MS;                   watchTimer = Executors.newSingleThreadScheduledExecutor();                   watchTimer.scheduleWithFixedDelay(watcher, reloadIntervalMs,                   reloadIntervalMs, TimeUnit.MILLISECONDS);            }                       protected class ConfigFileWatcher extends AbstractFileWatcher            {                      public ConfigFileWatcher(String watchedResource)                      {                                 super(watchedResource);                      }                        @Override                      protected synchronized void onChange(File file)                      {                                 deploy();                      }            }                       public void deploy()            {                      InputStream inputStream = null;                      try {                                 inputStream = new FileInputStream(new File(absoluteResourcePaths [0]));                      } catch (FileNotFoundException e1)  {                                                     e1.printStackTrace();                      }                      // TODO: implementation                      if (inputStream != null)                     {                                 try {                                           inputStream.close();                                 } catch (IOException e) {                                           e.printStackTrace();                                 }                      }            }   }

 

 

<AbstractFileWatcher class>

package test.watcher;   import java.io.File;   import org.apache.log4j.Logger;   public abstract class AbstractFileWatcher implements Runnable {              private transient Logger logger = Logger.getLogger(getClass());              private long timeStamp;            private File file;              public AbstractFileWatcher(String file_path)            {                      this.file = new File(file_path);                      this.timeStamp = file.lastModified();            }              public final void run()            {                                    long timeStamp = file.lastModified();                                         if   (this.timeStamp != timeStamp) {                                 this.timeStamp = timeStamp;                                 try {                                           onChange(file);                                 } catch (Throwable t) {                                           logger.error(String.format("Monitor for %s threw an exception", file), t);                                 }                      }                               }              protected abstract void onChange(File file); }

 

[출처] 파일 감시 데몬 만들기|작성자 zulu