Spring Boot Integration Logback Ultimate Guide to From Basic to Advanced Configuration

<!-- existSpring BootIn the project，You don't need to add explicitlyLogbackrely -->
<dependency>
    <groupId></groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>

import org.;
import org.;
@RestController
public class DemoController {
    // Get the Logger instance, usually taking the current class as a parameter    private static final Logger logger = ();
    @GetMapping("/demo")
    public String demo() {
        ("This is a TRACE level message");
        ("This is a DEBUG level message");
        ("This is an INFO level message");
        ("This is a WARN level message");
        ("This is an ERROR level message");
        return "Check your console or log file!";
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <!-- Attribute definition -->
    <property name="LOG_HOME" value="./logs" />
    <!-- definitionappender -->
    <appender name="CONSOLE" class="">
        <!-- encoderdefinition日志输出格式 -->
        <encoder>
            <pattern>%d{yyyy-MM-dd HH:mm:} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>
    <!-- definitionlogger -->
    <logger name="" level="DEBUG" />
    <!-- rootloggerConfiguration -->
    <root level="INFO">
        <appender-ref ref="CONSOLE" />
    </root>
</configuration>

<configuration scan="true" scanPeriod="30 seconds" debug="false">
    <!-- Configuration content -->
</configuration>

<!-- Direct definition -->
<property name="LOG_HOME" value="/var/logs/myapp" />
<!-- Get from system environment variable -->
<property name="LOG_HOME" value="${LOG_DIR:-./logs}" />
<!-- Load from external file -->
<property file="conf/" />
<!-- existSpring BootUsed in -->
<springProperty scope="context" name="appName" source="" />

<timestamp key="bySecond" datePattern="yyyyMMdd'T'HHmmss" />
<property name="LOG_FILE" value="${LOG_HOME}/log-${bySecond}.log" />

<appender name="UNIQUE_NAME" class="APPENDER_CLASS">
    <!-- Filter configuration -->
    <filter class="" />
    <!-- layout/Encoder configuration -->
    <encoder>
        <pattern>%d{yyyy-MM-dd HH:mm:ss} %msg%n</pattern>
    </encoder>
    <!-- Other unique configurations -->
</appender>

<appender name="STDOUT" class="">
    <target></target>
    <encoder>
        <pattern>%d{HH:mm:} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
</appender>

<appender name="FILE" class="">
    <file>${LOG_HOME}/</file>
    <append>true</append>
    <encoder>
        <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
</appender>

<appender name="ROLLING_FILE" class="">
    <file>${LOG_HOME}/</file>
    <rollingPolicy class="">
        <fileNamePattern>${LOG_HOME}/myapp.%d{yyyy-MM-dd}.log</fileNamePattern>
        <maxHistory>30</maxHistory>
    </rollingPolicy>
    <encoder>
        <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
</appender>

<encoder class="">
    <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
    <outputPatternAsHeader>false</outputPatternAsHeader>
    <charset>UTF-8</charset>
</encoder>

<encoder class="">
    <layout class="">
        <pattern>%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </layout>
</encoder>

<filter class="">
    <level>ERROR</level>
    <onMatch>ACCEPT</onMatch>  <!-- Actions when matching -->
    <onMismatch>DENY</onMismatch>  <!-- 不Actions when matching -->
</filter>

<filter class="">
    <level>WARN</level>
</filter>

<filter class="">
    <evaluator class="">
        <expression>
            () >= () && 
            ().contains("important")
        </expression>
    </evaluator>
    <onMatch>ACCEPT</onMatch>
    <onMismatch>DENY</onMismatch>
</filter>

public class SampleFilter extends Filter<ILoggingEvent> {
    @Override
    public FilterReply decide(ILoggingEvent event) {
        if (().contains("special")) {
            return ;
        }
        return ;
    }
}

<filter class="" />

<!-- Configure log levels for specific packages -->
<logger name="" level="DEBUG" />
<!-- Configure log levels for specific classes and disable themadditivity -->
<logger name="" level="TRACE" additivity="false">
    <appender-ref ref="SPECIAL_APPENDER" />
</logger>

<root level="INFO">
    <appender-ref ref="CONSOLE" />
    <appender-ref ref="FILE" />
</root>

<turboFilter class="">
    <Marker>important</Marker>
    <OnMatch>ACCEPT</OnMatch>
    <OnMismatch>NEUTRAL</OnMismatch>
</turboFilter>

<springProperty scope="context" name="appName" source="" defaultValue="myApp"/>
<property name="LOG_HOME" value="./logs/${appName}" />

<springProfile name="dev">
    <logger name="" level="DEBUG" />
</springProfile>
<springProfile name="prod">
    <logger name="" level="INFO" />
    <root level="WARN">
        <appender-ref ref="FILE" />
    </root>
</springProfile>

<rollingPolicy class="">
    <fileNamePattern>${LOG_HOME}/application.%d{yyyy-MM-dd}.log</fileNamePattern>
    <maxHistory>30</maxHistory>
</rollingPolicy>

<rollingPolicy class="">
    <fileNamePattern>${LOG_HOME}/application.%d{yyyy-MM-dd}.%</fileNamePattern>
    <maxFileSize>10MB</maxFileSize>
    <maxHistory>30</maxHistory>
    <totalSizeCap>1GB</totalSizeCap>
</rollingPolicy>

<appender name="ERROR_FILE" class="">
    <filter class="">
        <level>ERROR</level>
        <onMatch>ACCEPT</onMatch>
        <onMismatch>DENY</onMismatch>
    </filter>
    <!-- Other configurations -->
</appender>

<appender name="WARN_FILE" class="">
    <filter class="">
        <level>WARN</level>
    </filter>
    <!-- Other configurations -->
</appender>

<appender name="ASYNC_FILE" class="">
    <queueSize>512</queueSize>
    <discardingThreshold>0</discardingThreshold>
    <includeCallerData>false</includeCallerData>
    <appender-ref ref="FILE" />
</appender>

import org.;
public class UserService {
    private static final Logger logger = ();
    public void login(String userId) {
        ("userId", userId);
        ("User logged in");
        ("userId");
    }
}

<pattern>%d{yyyy-MM-dd HH:mm:} [%thread] [%X{userId}] %-5level %logger{36} - %msg%n</pattern>

<!-- Only whenMDCExist inuserIdShown only when -->
<pattern>%d{yyyy-MM-dd} [%thread] %mdc{userId:-} %-5level %logger{36} - %msg%n</pattern>

<if condition='property("env").equals("prod")'>
    <then>
        <root level="WARN">
            <appender-ref ref="FILE" />
        </root>
    </then>
    <else>
        <root level="DEBUG">
            <appender-ref ref="CONSOLE" />
        </root>
    </else>
</if>

<!-- Make sure the trigger policy is configured -->
<rollingPolicy class="">
    <fileNamePattern>logs/app-%d{yyyy-MM-dd}.%</fileNamePattern>
    <maxFileSize>50MB</maxFileSize>  <!-- Must be configured -->
    <maxHistory>30</maxHistory>
</rollingPolicy>

<encoder>
    <pattern>%msg%n</pattern>
    <charset>UTF-8</charset>  <!-- Identify the character set -->
</encoder>

<?xml version="1.0" encoding="UTF-8"?>
<!-- LogbackRoot tag of configuration file，All configuration elements must be included in this tag -->
<configuration>
    <!-- Attribute definition section，pass <property> Tag definition reusable properties，Convenient to reference in configuration files -->
    <!-- Define the home directory for log file storage -->
    <property name="LOG_HOME" value="/var/logs/myapp" />
    <!-- Define the format pattern of log output，Included date and time、Thread name、Log Level、Logger name and log message -->
    <property name="LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:} [%thread] %-5level %logger{36} - %msg%n" />
    <!-- ConsoleAppenderConfiguration，用于Will日志输出到Console -->
    <appender name="CONSOLE" class="">
        <!-- 编码器Configuration，Convert log events to strings of specified format -->
        <encoder>
            <!-- Use the log format pattern defined earlier -->
            <pattern>${LOG_PATTERN}</pattern>
        </encoder>
        <!-- 过滤器Configuration，Only allowed指定级别及以上的日志pass -->
        <filter class="">
            <!-- Set the filtering level to WARN，That is, only output WARN Logs at or above levels -->
            <level>WARN</level>
        </filter>
    </appender>
    <!-- Main fileAppenderConfiguration，Used to output logs to files，And support rolling policy -->
    <appender name="FILE" class="">
        <!-- Specify the path to the log file，Use the log home directory defined earlier -->
        <file>${LOG_HOME}/</file>
        <!-- 编码器Configuration，Convert log events to strings of specified format -->
        <encoder>
            <!-- Use the log format pattern defined earlier -->
            <pattern>${LOG_PATTERN}</pattern>
        </encoder>
        <!-- 滚动策略Configuration，Scroll based on file size and time -->
        <rollingPolicy class="">
            <!-- Scrolled file naming mode，Include date and serial number -->
            <fileNamePattern>${LOG_HOME}/application.%d{yyyy-MM-dd}.%</fileNamePattern>
            <!-- Maximum size of a single log file，More than this size will scroll -->
            <maxFileSize>50MB</maxFileSize>
            <!-- Maximum number of days of historical log files retained -->
            <maxHistory>30</maxHistory>
            <!-- The maximum total size of all log files -->
            <totalSizeCap>5GB</totalSizeCap>
        </rollingPolicy>
    </appender>
    <!-- Error logAppenderConfiguration，Specially used for recording ERROR Level log -->
    <appender name="ERROR_FILE" class="">
        <!-- 指定Error log文件的路径，Use the log home directory defined earlier -->
        <file>${LOG_HOME}/</file>
        <!-- 编码器Configuration，Convert log events to strings of specified format -->
        <encoder>
            <!-- Use the log format pattern defined earlier -->
            <pattern>${LOG_PATTERN}</pattern>
        </encoder>
        <!-- 过滤器Configuration，Only allowed ERROR Level logpass -->
        <filter class="">
            <!-- Set the filtering level to ERROR -->
            <level>ERROR</level>
            <!-- 当Log Level匹配时，允许pass -->
            <onMatch>ACCEPT</onMatch>
            <!-- 当Log Level不匹配时，拒绝pass -->
            <onMismatch>DENY</onMismatch>
        </filter>
        <!-- 滚动策略Configuration，Roll based on time -->
        <rollingPolicy class="">
            <!-- Scrolled file naming mode，Included dates -->
            <fileNamePattern>${LOG_HOME}/error.%d{yyyy-MM-dd}.log</fileNamePattern>
            <!-- 保留的历史Error log文件的最大天数 -->
            <maxHistory>90</maxHistory>
        </rollingPolicy>
    </appender>
    <!-- asynchronousAppenderConfiguration，用于asynchronous处理日志，Improve performance -->
    <appender name="ASYNC_FILE" class="">
        <!-- asynchronous队列的大小，That is, the maximum number of log events that can be cached -->
        <queueSize>1024</queueSize>
        <!-- Discard threshold，When the remaining space of the queue is less than this value，Some log events will be discarded，Set as 0 Indicates not to discard -->
        <discardingThreshold>0</discardingThreshold>
        <!-- 引用前面定义的Main fileAppender，Willasynchronous处理后的日志输出到该 Appender -->
        <appender-ref ref="FILE" />
    </appender>
    <!-- LoggerConfiguration部分，用于指定不同包或kind的Log Level和输出目的地 -->
    <!-- against  Bag and its sub-packages，设置Log Level为 INFO -->
    <logger name="" level="INFO" />
    <!-- against  Bag and its sub-packages，设置Log Level为 WARN -->
    <logger name="" level="WARN" />
    <!-- against  kind，设置Log Level为 DEBUG，And turn off the log addition -->
    <logger name="" level="DEBUG" additivity="false">
        <!-- 只Will该kind的日志输出到Main fileAppender -->
        <appender-ref ref="FILE" />
    </logger>
    <!-- Root LoggerConfiguration，It's all Logger The father Logger，设置全局的Log Level和输出目的地 -->
    <root level="INFO">
        <!-- Will日志输出到ConsoleAppender -->
        <appender-ref ref="CONSOLE" />
        <!-- Will日志asynchronous输出到Main fileAppender -->
        <appender-ref ref="ASYNC_FILE" />
        <!-- Will ERROR Level log输出到Error logAppender -->
        <appender-ref ref="ERROR_FILE" />
    </root>
</configuration>

<?xml version="1.0" encoding="UTF-8"?>
<!-- Logback Root tag of configuration file，All configuration items must be included -->
<configuration>
    <!-- use springProperty Tags from Spring Get attribute values ​​in context。
         scope="context" Indicates from Spring Context Getting Attributes，
         name="appName" Define attribute name，
         source="" Specify from Spring Get the name in the configuration  attribute value，
         defaultValue="myApp" If no attribute value is obtained，则use默认值 myApp -->
    <springProperty scope="context" name="appName" source="" defaultValue="myApp"/>
    <!-- Define the home directory properties of the log store，The path is /var/log/ Add the name of the application obtained earlier -->
    <property name="LOG_HOME" value="/var/log/${appName}" />
    <!-- Define the format pattern of log output，Included date and time、Thread name、Log Level、Logger name and log message -->
    <property name="LOG_PATTERN" value="%d{yyyy-MM-dd HH:mm:} [%thread] %-5level %logger{36} - %msg%n" />
    <!-- Asynchronous file output Appender Configuration，Write logs asynchronously to files for performance improvements -->
    <appender name="ASYNC_FILE" class="">
        <!-- The size of the asynchronous queue，That is, the maximum number of log events that can be cached is 512 -->
        <queueSize>512</queueSize>
        <!-- Discard threshold，Set as 0 Indicates that log events are not discarded -->
        <discardingThreshold>0</discardingThreshold>
        <!-- Quote name FILE of Appender，将异步处理后of日志发送到该 Appender -->
        <appender-ref ref="FILE" />
    </appender>
    <!-- Main log file Appender Configuration，Used to write logs to files and support scrolling policies -->
    <appender name="FILE" class="">
        <!-- 指定日志文件of路径，use前面定义of日志主目录 -->
        <file>${LOG_HOME}/</file>
        <!-- 编码器Configuration，将日志事件转换为指定格式of字符串 -->
        <encoder>
            <!-- use前面定义of日志格式模式 -->
            <pattern>${LOG_PATTERN}</pattern>
        </encoder>
        <!-- 滚动策略Configuration，Scroll based on file size and time -->
        <rollingPolicy class="">
            <!-- 滚动后of文件命名模式，Include date and serial number -->
            <fileNamePattern>${LOG_HOME}/application.%d{yyyy-MM-dd}.%</fileNamePattern>
            <!-- 单个日志文件of最大大小，More than this size will scroll -->
            <maxFileSize>50MB</maxFileSize>
            <!-- 保留of历史日志文件of最大天数 -->
            <maxHistory>30</maxHistory>
            <!-- 所有日志文件of总大小上限 -->
            <totalSizeCap>5GB</totalSizeCap>
        </rollingPolicy>
    </appender>
    <!-- Error log asynchronous output Appender Configuration，Write error logs asynchronously to file -->
    <appender name="ASYNC_ERROR_FILE" class="">
        <!-- The size of the asynchronous queue，That is, the maximum number of log events that can be cached is 512 -->
        <queueSize>512</queueSize>
        <!-- Discard threshold，Set as 0 Indicates that log events are not discarded -->
        <discardingThreshold>0</discardingThreshold>
        <!-- Quote name ERROR_FILE of Appender，将异步处理后of错误日志发送到该 Appender -->
        <appender-ref ref="ERROR_FILE" />
    </appender>
    <!-- Error log file Appender Configuration，Specifically used to log error logs and support scrolling policies -->
    <appender name="ERROR_FILE" class="">
        <!-- 指定Error log fileof路径，use前面定义of日志主目录 -->
        <file>${LOG_HOME}/</file>
        <!-- 过滤器Configuration，Only allowed ERROR 及以上级别of日志通过 -->
        <filter class="">
            <!-- Set the filtering level to ERROR -->
            <level>ERROR</level>
        </filter>
        <!-- 编码器Configuration，将日志事件转换为指定格式of字符串 -->
        <encoder>
            <!-- use前面定义of日志格式模式 -->
            <pattern>${LOG_PATTERN}</pattern>
        </encoder>
        <!-- 滚动策略Configuration，Scroll based on file size and time -->
        <rollingPolicy class="">
            <!-- 滚动后of文件命名模式，Include date and serial number -->
            <fileNamePattern>${LOG_HOME}/error.%d{yyyy-MM-dd}.%</fileNamePattern>
            <!-- 单个Error log fileof最大大小，More than this size will scroll -->
            <maxFileSize>50MB</maxFileSize>
            <!-- 保留of历史Error log fileof最大天数 -->
            <maxHistory>60</maxHistory>
            <!-- 所有Error log fileof总大小上限 -->
            <totalSizeCap>10GB</totalSizeCap>
        </rollingPolicy>
    </appender>
    <!-- Email Notification Appender Configuration，When an error log appears发送Email Notification -->
    <appender name="EMAIL" class="">
        <!-- SMTP Server address -->
        <smtpHost></smtpHost>
        <!-- SMTP Server Port -->
        <smtpPort>587</smtpPort>
        <!-- Sender Email Username -->
        <username>user@</username>
        <!-- Sender's email password -->
        <password>password</password>
        <!-- Recipient email address -->
        <to>admin@</to>
        <!-- Sender email address -->
        <from>noreply@</from>
        <!-- Email Subject，Includes the application name、Logger name and log message -->
        <subject>${appName} - ERROR: %logger{20} - %m</subject>
        <!-- 邮件内容布局Configuration -->
        <layout class="">
            <!-- 邮件内容of格式模式，Included date and time、Thread name、Log Level、Logger name、Log messages and exception information -->
            <pattern>%d{yyyy-MM-dd HH:mm:} [%thread] %-5level %logger{36} - %msg%n%ex</pattern>
        </layout>
        <!-- 循环缓冲区跟踪器Configuration，用于缓存一定数量of日志事件 -->
        <cyclicBufferTracker class="">
            <!-- Buffer size，That is, the maximum cache 10 Log Events -->
            <bufferSize>10</bufferSize>
        </cyclicBufferTracker>
    </appender>
    <!-- Root Logger Configuration，It's all Logger of父 Logger，设置全局ofLog Level和输出目of地 -->
    <root level="WARN">
        <!-- 将日志异步输出到Main log file Appender -->
        <appender-ref ref="ASYNC_FILE" />
        <!-- 将Error log asynchronous output到Error log file Appender -->
        <appender-ref ref="ASYNC_ERROR_FILE" />
        <!-- When an error log appears，发送Email Notification -->
        <appender-ref ref="EMAIL" />
    </root>
</configuration>