• 运行 LogEventBroadcaster 和 LogEventMonitor

    运行 LogEventBroadcaster 和 LogEventMonitor

    如上所述,我们将使用 Maven 来运行应用程序。这一次你需要打开两个控制台窗口给每个项目。用 Ctrl-C 可以停止它。

    首先我们将启动 LogEventBroadcaster 如清单13.4所示,除了已经构建项目以下命令即可(使用默认值):

    1. $ mvn exec:exec -Pchapter13-LogEventBroadcaster

    和之前一样,这将通过 UDP 广播日志消息。

    现在,在一个新窗口,构建和启动 LogEventMonitor 接收和显示广播消息。

    Listing 13.9 Compile and start the LogEventBroadcaster

    1. $ mvn clean package exec:exec -Pchapter13-LogEventMonitor
    2. [INFO] Scanning for projects...
    3. [INFO]
    4. [INFO] --------------------------------------------------------------------
    5. [INFO] Building netty-in-action 0.1-SNAPSHOT
    6. [INFO] --------------------------------------------------------------------
    7. ...
    8. [INFO]
    9. [INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ netty-in-action ---
    10. [INFO] Building jar: /Users/norman/Documents/workspace-intellij/netty-in-actionprivate/
    11. target/netty-in-action-0.1-SNAPSHOT.jar
    12. [INFO]
    13. [INFO] --- exec-maven-plugin:1.2.1:exec (default-cli) @ netty-in-action ---
    14. LogEventMonitor running

    当看到 “LogEventMonitor running” 说明程序运行成功了。

    控制台将显示任何事件被添加到日志文件中,如下所示。消息的格式是由LogEventHandler 创建。

    Listing 13.10 LogEventMonitor output

    1. 1364217299382 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 13:55:08 dev-linux
    2. dhclient: DHCPREQUEST of 192.168.0.50 on eth2 to 192.168.0.254 port 67
    3. 1364217299382 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 13:55:08 dev-linux
    4. dhclient: DHCPACK of 192.168.0.50 from 192.168.0.254
    5. 1364217299382 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 13:55:08 dev-linux
    6. dhclient: bound to 192.168.0.50 -- renewal in 270 seconds.
    7. 1364217299382 [/192.168.0.38:63182] [[/var/log/messages] : Mar 25 13:59:38 dev-linux
    8. dhclient: DHCPREQUEST of 192.168.0.50 on eth2 to 192.168.0.254 port 67
    9. 1364217299382 [/192.168.0.38:63182] [/[/var/log/messages] : Mar 25 13:59:38 dev-linux
    10. dhclient: DHCPACK of 192.168.0.50 from 192.168.0.254
    11. 1364217299382 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 13:59:38 dev-linux
    12. dhclient: bound to 192.168.0.50 -- renewal in 259 seconds.
    13. 1364217299383 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 14:03:57 dev-linux
    14. dhclient: DHCPREQUEST of 192.168.0.50 on eth2 to 192.168.0.254 port 67
    15. 1364217299383 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 14:03:57 dev-linux
    16. dhclient: DHCPACK of 192.168.0.50 from 192.168.0.254
    17. 1364217299383 [/192.168.0.38:63182] [/var/log/messages] : Mar 25 14:03:57 dev-linux
    18. dhclient: bound to 192.168.0.50 -- renewal in 285 seconds.

    若你没有访问 UNIX syslog 的权限，可以创建 自定义的文件，手动填入内容。下面是 UNIX 命令用 touch 创建一个空文件

    1. $ touch ~/mylog.log

    再次启动 LogEventBroadcaster，设置系统属性

    1. $ mvn exec:exec -Pchapter13-LogEventBroadcaster -Dlogfile=~/mylog.log

    当 LogEventBroadcaster 运行时，你可以手动的添加消息到文件来查看广播到 LogEventMonitor 控制台的内容。使用 echo 和输出的文件

    1. $ echo ’Test log entry’ >> ~/mylog.log

    你可以启动任意个监视器实例，他们都会收到相同的消息。