spring 提供的 Logging :: Spring Boot 有以下幾種
| name | package |
|---|---|
| Java Util Logging | spring-boot-starter-logging |
| Logback | spring-boot-starter-logging |
| Log4j2 | spring-boot-starter-log4j2 |
spring-boot-starter-logging 是預設引用的，所有 spring-boot-starter-* 都會引用 spring-boot-starter-logging。不需要自行引用。
spring-boot-starter-logging 使用 Commons Logging，支援 Java Util Logging、Log4j2、Logback
使用 starter 預設會使用 Logback，透過 logback 支援 Java Util Logging, Commons Logging, Log4J, or SLF4J。
Log Format
2024-11-15T17:25:40.765+08:00 INFO 4924 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port 8080 (http)Date & Time
Log Level
Process ID
---separator[Application name] 如果有設定
spring.application.name才會出現[Thread name]
Correlation ID 如果有設定 tracing 才會出現
Logger name 通常是來源 class name 的縮寫
log message
Console Output
預設會出現 ERROR-level, WARN-level, and INFO-level messages
如果在 CLI 有加上 java -jar Demo1.jar --debug debug flag，就會出現 core loggers (embedded container, Hibernate, and Spring Boot) 更多的資訊。這邊不代表 application 的 DEBUG level message 會出現
CLI 也可以加上 --trace ，會增加 core logger 資訊
Color-coded Output
terminal 有支援 ANSI 時，就可以增加顏色
ex: %clr(%5p)
| Level | Color |
|---|---|
FATAL |
Red |
ERROR |
Red |
WARN |
Yellow |
INFO |
Green |
DEBUG |
Green |
TRACE |
Green |
可以自訂顏色
bluecyanfaintgreenmagentaredyellow
ex: %clr(%d{yyyy-MM-dd'T'HH:mm:ss.SSSXXX}){yellow}
File Output
spring boot 預設只會寫入 console log
要寫入 file log 必須設定 logging.file.name 或 logging.file.path，兩個都設定時，只會使用 logging.file.name。log file rotate 預設為 10M，log level 跟 console 一樣，會寫入 ERROR, WARN, INFO level
File Rotation
調整 log rotate 規則
要修改 application.properties(yaml)，如果是 log4j 就要設定 log4j2.xml or log4j2-spring.xml
| name | desc |
|---|---|
| logging.logback.rollingpolicy.file-name-pattern | filename pattern |
| logging.logback.rollingpolicy.clean-history-on-start | 在 application 啟動時，要做 log cleanup |
| logging.logback.rollingpolicy.max-file-size | logfile 的最大 size |
| logging.logback.rollingpolicy.total-size-cap | log archives 刪除前的最大 size |
| logging.logback.rollingpolicy.max-history | archive log files 保留幾個(default: 7) |
Log Level
logging.level.<logger-name>=<level>為 TRACE, DEBUG, INFO, WARN, ERROR, FATAL, or OFF 其中一個
logging.level.root 是設定 root logger
logging:
level:
root: "warn"
org.springframework.web: "debug"
org.hibernate: "error"也可以設定環境變數，ex:
LOGGING_LEVEL_ORG_SPRINGFRAMEWORK_WEB=DEBUGLog Groups
ex: 一次設定所有 tomcat 相關的 logger level，group 合併後，再設定 level
在 applicaiton.yaml
logging:
group:
tomcat: "org.apache.catalina,org.apache.coyote,org.apache.tomcat"
logging:
level:
tomcat: "trace"spring pre-defined logging groups
| name | loggers |
|---|---|
| web | org.springframework.core.codec, org.springframework.http, org.springframework.web, org.springframework.boot.actuate.endpoint.web, org.springframework.boot.web.servlet.ServletContextInitializerBeans |
| sql | org.springframework.jdbc.core, org.hibernate.SQL, org.jooq.tools.LoggerListener |
Log Shutdown hook
要在 application 關閉前，release logging resource，要在 JVM exits 時，加上 shutdown hook
使用 jar 時，shutdown hook 會自動註冊
如要關閉 shutdown hook
logging:
register-shutdown-hook: falseCustom Log Configuration
logging.config 決定 logging framework，然後就能使用該 framework 的設定檔
| Logging System | Customization |
|---|---|
| Logback | logback-spring.xml, logback-spring.groovy, logback.xml, or logback.groovy |
| Log4j2 | log4j2-spring.xml or log4j2.xml |
| JDK (Java Util Logging) | logging.properties |
建議使用 logback-spring.xml，不要用 logback.xml，spring 可能會無法控制 log 初始化
以下設定參數，可轉換為環境變數
| Spring Environment | System Property | Comments |
|---|---|---|
logging.exception-conversion-word |
LOG_EXCEPTION_CONVERSION_WORD |
The conversion word used when logging exceptions. |
logging.file.name |
LOG_FILE |
If defined, it is used in the default log configuration. |
logging.file.path |
LOG_PATH |
If defined, it is used in the default log configuration. |
logging.pattern.console |
CONSOLE_LOG_PATTERN |
The log pattern to use on the console (stdout). |
logging.pattern.dateformat |
LOG_DATEFORMAT_PATTERN |
Appender pattern for log date format. |
logging.charset.console |
CONSOLE_LOG_CHARSET |
The charset to use for console logging. |
logging.threshold.console |
CONSOLE_LOG_THRESHOLD |
The log level threshold to use for console logging. |
logging.pattern.file |
FILE_LOG_PATTERN |
The log pattern to use in a file (if LOG_FILE is enabled). |
logging.charset.file |
FILE_LOG_CHARSET |
The charset to use for file logging (if LOG_FILE is enabled). |
logging.threshold.file |
FILE_LOG_THRESHOLD |
The log level threshold to use for file logging. |
logging.pattern.level |
LOG_LEVEL_PATTERN |
The format to use when rendering the log level (default %5p). |
PID |
PID |
使用 logback，可多使用這些參數
| Spring Environment | System Property | Comments |
|---|---|---|
logging.logback.rollingpolicy.file-name-pattern |
LOGBACK_ROLLINGPOLICY_FILE_NAME_PATTERN |
Pattern for rolled-over log file names (default ${LOG_FILE}.%d{yyyy-MM-dd}.%i.gz). |
logging.logback.rollingpolicy.clean-history-on-start |
LOGBACK_ROLLINGPOLICY_CLEAN_HISTORY_ON_START |
Whether to clean the archive log files on startup. |
logging.logback.rollingpolicy.max-file-size |
LOGBACK_ROLLINGPOLICY_MAX_FILE_SIZE |
Maximum log file size. |
logging.logback.rollingpolicy.total-size-cap |
LOGBACK_ROLLINGPOLICY_TOTAL_SIZE_CAP |
Total size of log backups to be kept. |
logging.logback.rollingpolicy.max-history |
LOGBACK_ROLLINGPOLICY_MAX_HISTORY |
Logback Extension
logback-spring.xml 裡面有幾個 logback extensions
profile-specific cofiguration
根據 active profile，<springProfile> 可 include/exclude 部分設定
<springProfile name="staging">
<!-- configuration to be enabled when the "staging" profile is active -->
</springProfile>
<springProfile name="dev | staging">
<!-- configuration to be enabled when the "dev" or "staging" profiles are active -->
</springProfile>
<springProfile name="!production">
<!-- configuration to be enabled when the "production" profile is not active -->
</springProfile>environment properties
<springProperty scope="context" name="fluentHost" source="myapp.fluentd.host"
defaultValue="localhost"/>
<appender name="FLUENT" class="ch.qos.logback.more.appenders.DataFluentAppender">
<remoteHost>${fluentHost}</remoteHost>
...
</appender>example
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<property name="LOG_PATH" value="/var/log/blog"/>
<property name="LOG_FILENAME" value="spring-profiles"/>
<include resource="org/springframework/boot/logging/logback/defaults.xml"/>
<include resource="org/springframework/boot/logging/logback/console-appender.xml"/>
<springProfile name="default,ide">
<root level="INFO">
<appender-ref ref="CONSOLE"/>
</root>
</springProfile>
<springProfile name="test,prod">
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<encoder>
<pattern>${FILE_LOG_PATTERN}</pattern>
</encoder>
<file>${LOG_PATH}/${LOG_FILENAME}.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
<fileNamePattern>${LOG_PATH}/${LOG_FILENAME}-%d{yyyy-MM-dd}.%i.log</fileNamePattern>
<maxHistory>7</maxHistory>
<maxFileSize>100MB</maxFileSize>
<totalSizeCap>1GB</totalSizeCap>
</rollingPolicy>
</appender>
<root level="INFO">
<appender-ref ref="FILE"/>
</root>
</springProfile>
</configuration>Log4j2 Extension
可在 log4j2-spring.xml 設定使用
profile-specific configuration
<SpringProfile name="staging">
<!-- configuration to be enabled when the "staging" profile is active -->
</SpringProfile>
<SpringProfile name="dev | staging">
<!-- configuration to be enabled when the "dev" or "staging" profiles are active -->
</SpringProfile>
<SpringProfile name="!production">
<!-- configuration to be enabled when the "production" profile is not active -->
</SpringProfile> Environment Properties Lookup
<Properties>
<Property name="applicationName">${spring:spring.application.name}</Property>
</Properties>log4j2 system properties
ex: ConsoleAppender 在 windows 使用 Jansi
log4j2.skipJansi=false