go get -u github.com/alecthomas/log4go

<logging>
    <filter enabled="true">
        <tag>stdout</tag>
        <type>console</type>
        <!-- level is (:?FINEST|FINE|DEBUG|TRACE|INFO|WARNING|ERROR) -->
        <level>DEBUG</level>
    </filter>
    <filter enabled="true">
        <tag>file</tag>
        <type>file</type>
        <level>INFO</level>
        <property name="filename">test_client.log</property>
        <!--
           %T - Time (15:04:05 MST)
           %t - Time (15:04)
           %D - Date (2006/01/02)
           %d - Date (01/02/06)
           %L - Level (FNST, FINE, DEBG, TRAC, WARN, EROR, CRIT)
           %S - Source
           %M - Message
           It ignores unknown format strings (and removes them)
           Recommended: "[%D %T] [%L] (%S) %M"
        -->
        <property name="format">[%D %T] [%L] (%S) %M</property>
        <property name="rotate">false</property> <!-- true enables log rotation, otherwise append -->
        <property name="maxsize">10M</property> <!-- \d+[KMG]? Suffixes are in terms of 2**10 -->
        <property name="maxlines">0K</property> <!-- \d+[KMG]? Suffixes are in terms of thousands -->
        <property name="daily">false
        </property> <!-- Automatically rotates when a log message is written after midnight -->
    </filter>
    <filter enabled="false">
        <tag>xmllog</tag>
        <type>xml</type>
        <level>INFO</level>
        <property name="filename">trace.xml</property>
        <property name="rotate">true</property> <!-- true enables log rotation, otherwise append -->
        <property name="maxsize">100M</property> <!-- \d+[KMG]? Suffixes are in terms of 2**10 -->
        <property name="maxrecords">6K</property> <!-- \d+[KMG]? Suffixes are in terms of thousands -->
        <property name="daily">false
        </property> <!-- Automatically rotates when a log message is written after midnight -->
    </filter>
    <filter enabled="false"><!-- enabled=false means this logger won't actually be created -->
        <tag>donotopen</tag>
        <type>socket</type>
        <level>FINEST</level>
        <property name="endpoint">192.168.1.255:12124</property> <!-- recommend UDP broadcast -->
        <property name="protocol">udp</property> <!-- tcp or udp -->
    </filter>
</logging>

func init() {
    log.LoadConfiguration("log4go.xml")
}

//导包 log "github.com/alecthomas/log4go"
log.Info("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx")

log.Debug("111111111111111111111111111")