3.11. サーバーライフサイクルイベントの通知

例: リスナークラス

package org.simple.lifecycle.events.listener;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import org.wildfly.extension.core.management.client.ProcessStateListener;
import org.wildfly.extension.core.management.client.ProcessStateListenerInitParameters;
import org.wildfly.extension.core.management.client.RunningStateChangeEvent;
import org.wildfly.extension.core.management.client.RuntimeConfigurationStateChangeEvent;

public class SimpleListener implements ProcessStateListener {

    private File file;
    private FileWriter fileWriter;
    private ProcessStateListenerInitParameters parameters;

    public void init(ProcessStateListenerInitParameters parameters) {
        this.parameters = parameters;
        this.file = new File(parameters.getInitProperties().get("file"));
        try {
            fileWriter = new FileWriter(file, true);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void cleanup() {
        try {
            fileWriter.close();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            fileWriter = null;
        }
    }

    public void runtimeConfigurationStateChanged(RuntimeConfigurationStateChangeEvent evt) {
        try {
            fileWriter.write(String.format("Runtime configuration state change for %s: %s to %s\n", parameters.getProcessType(), evt.getOldState(), evt.getNewState()));
            fileWriter.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void runningStateChanged(RunningStateChangeEvent evt) {
        try {
            fileWriter.write(String.format("Running state change for %s: %s to %s\n", parameters.getProcessType(), evt.getOldState(), evt.getNewState()));
            fileWriter.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

例: リスナークラス

import java.io.BufferedWriter;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;

import javax.management.AttributeChangeNotification;
import javax.management.Notification;
import javax.management.NotificationListener;

import org.jboss.logging.Logger;

public class StateNotificationListener implements NotificationListener {

  public static final String RUNTIME_CONFIGURATION_FILENAME = "runtime-configuration-notifications.txt";
  public static final String RUNNING_FILENAME = "running-notifications.txt";
  private final Path targetFile;

  public StateNotificationListener() {
    this.targetFile = Paths.get("notifications/data").toAbsolutePath();
    init(targetFile);
  }

  protected Path getRuntimeConfigurationTargetFile() {
    return this.targetFile.resolve(RUNTIME_CONFIGURATION_FILENAME);
  }

  protected Path getRunningConfigurationTargetFile() {
    return this.targetFile.resolve(RUNNING_FILENAME);
  }

  protected final void init(Path targetFile) {
    try {
      Files.createDirectories(targetFile);

      if (!Files.exists(targetFile.resolve(RUNTIME_CONFIGURATION_FILENAME))) {
        Files.createFile(targetFile.resolve(RUNTIME_CONFIGURATION_FILENAME));
      }

      if (!Files.exists(targetFile.resolve(RUNNING_FILENAME))) {
        Files.createFile(targetFile.resolve(RUNNING_FILENAME));
      }
    } catch (IOException ex) {
        Logger.getLogger(StateNotificationListener.class).error("Problem handling JMX Notification", ex);
    }
  }

  @Override
  public void handleNotification(Notification notification, Object handback) {
    AttributeChangeNotification attributeChangeNotification = (AttributeChangeNotification) notification;
    if ("RuntimeConfigurationState".equals(attributeChangeNotification.getAttributeName())) {
      writeNotification(attributeChangeNotification, getRuntimeConfigurationTargetFile());
    } else {
      writeNotification(attributeChangeNotification, getRunningConfigurationTargetFile());
    }
  }

  private void writeNotification(AttributeChangeNotification notification, Path path) {
    try (BufferedWriter in = Files.newBufferedWriter(path, StandardCharsets.UTF_8, StandardOpenOption.APPEND)) {
      in.write(String.format("%s %s %s %s", notification.getType(), notification.getSequenceNumber(), notification.getSource().toString(), notification.getMessage()));
      in.newLine();
      in.flush();
    } catch (IOException ex) {
      Logger.getLogger(StateNotificationListener.class).error("Problem handling JMX Notification", ex);
    }
  }
}

例: 通知リスナーの追加

MBeanServer server = ManagementFactory.getPlatformMBeanServer();
server.addNotificationListener(ObjectName.getInstance("jboss.root:type=state"), new StateNotificationListener(), null, null);