选择框架
logback.xml
配置文件。log4j2.xml
。LoggerFactory
获取Logger。配置文件示例(Logback)
<!-- 放置在src/main/resources目录 -->
<configuration>
<appender name="FILE" class="ch.qos.logback.core.FileAppender">
<file>/var/log/myapp/app.log</file>
<encoder>
<pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<root level="INFO">
<appender-ref ref="FILE" />
</root>
</configuration>
输出到文件
FileAppender
指定日志路径(如/var/log/myapp/
),确保目录权限正确(chmod 755 /var/log/myapp
)。StandardOutput=file:/path/to/log
重定向systemd
服务日志到文件。日志轮转与清理
logrotate
工具配置轮转策略(如按天/大小分割),示例配置:# /etc/logrotate.d/myapp
/var/log/myapp/*.log {
daily
rotate 7
compress
missingok
notifempty
}
命令行工具
tail -f /var/log/myapp/app.log
:实时查看日志。grep "ERROR" /var/log/myapp/app.log
:过滤错误日志。图形化工具
gnome-system-log
:查看系统及应用日志。Kibana
(搭配ELK栈):可视化分析日志,支持搜索、聚合。集中式管理(可选)
chown appuser:appgroup /var/log/myapp
)。/etc/systemd/system/myapp.service
),指定日志输出路径:[Service]
ExecStart=/usr/bin/java -jar /opt/myapp/app.jar
StandardOutput=file:/var/log/myapp/stdout.log
StandardError=file:/var/log/myapp/stderr.log
journalctl -u myapp
查看服务日志。参考来源: