Spring Boot 入门 - 基础篇（三）- 日志管理(Logback/Log4J2)

Spring Boot 入门 - 基础篇（3）- 日志管理(Logback/Log4J2)
Spring Boot支持JUL，Log4J2和Logback。

默认设置
-采用SLF4J + Logback
-日志只输出到控制台
-级别Level为INFO
-日志文件rotate大小为10Mb
-输出格式为：时间戳 级别 进程ID --- [线程名] 类名 日志内容


输出到文件
src/main/resources/application.properties

会在该目录下创建spring.log文件，输出内容和控制台相同。

详细配置
src/main/resources/application.properties

# Location of the log file. 
logging.file=d:\\spring-boot-demo.log
# Appender pattern
logging.pattern.console=%date %-5level %logger{0} - %msg%n
logging.pattern.file=%date %-5level [%thread] %logger{0} [%file:%line] - %msg%n
logging.pattern.level=%5p
# Log levels - root
logging.level.=DEBUG
# Log levels - package
logging.level.org.springframework.web=INFO
# Log levels - class
logging.level.com.rensanning.springboot.HomeController=TRACE

*** logging.file 和 logging.path不能同时设置

测试代码
src/main/java/com/rensanning/springboot/HelloController.java

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
	
    private final Logger log = LoggerFactory.getLogger(this.getClass());
	
    @RequestMapping("/")
    public String index() {
    	
        // Log a simple message
        log.debug("debug level log");
        log.info("info level log");
        log.warn("warn level log");
        log.error("error level log");
        
        return "Hello world from Spring Boot!";
    }
    
}

启动应用后访问 http://localhost:8080/。

控制台输出内容：

文件输出内容：


外部配置
src/main/resources/

• Logback -> logback.xml 或 logback-spring.xml
• Log4j2 -> log4j2.xml 或 log4j2-spring.xml
• JUL -> logging.properties

src/main/resources/logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="30 seconds">

    <property name="log.base" value="d:" />
    <property name="log.level" value="DEBUG" />

    <!-- Appenders -->
    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%-5level %logger{0} - %msg%n</pattern>
        </encoder>
    </appender>

    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${log.base}/SpringSample.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
            <fileNamePattern>${log.base}/SpringSample.%d{yyyyMMdd}.%i.log</fileNamePattern>
            <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
                <maxFileSize>5MB</maxFileSize>
            </timeBasedFileNamingAndTriggeringPolicy>
        </rollingPolicy>
        <encoder>
            <pattern>%date %-5level [%thread] %logger{0} [%file:%line] - %msg%n</pattern>
        </encoder>
    </appender>
    
    <!-- 3rdparty Logger -->
    <logger name="org.springframework" level="${log.level}" />
    <logger name="org.apache.commons" level="INFO" />
    <logger name="org.apache.tiles" level="INFO" />
    <logger name="org.apache.ibatis" level="${log.level}" />
    <logger name="org.apache.shiro" level="${log.level}" />
    <logger name="org.dozer" level="INFO" />
    <logger name="org.scribe" level="${log.level}" />
    
    <!-- Application Logger -->
    <logger name="com.rensanning.springboot" level="${log.level}" />
    
    <!-- Root Logger -->
    <root level="${log.level}">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
    </root>

</configuration>

启动应用后访问 http://localhost:8080/。

控制台输出内容：

文件输出内容：


SpringBoot默认配置文件
base.xml(console-appender.xml file-appender.xml)
https://github.com/spring-projects/spring-boot/blob/master/spring-boot/src/main/resources/org/springframework/boot/logging/logback/base.xml

<included>
	<include resource="org/springframework/boot/logging/logback/defaults.xml" />
	<property name="LOG_FILE" value="${LOG_FILE:-${LOG_PATH:-${LOG_TEMP:-${java.io.tmpdir:-/tmp}}}/spring.log}"/>
	<include resource="org/springframework/boot/logging/logback/console-appender.xml" />
	<include resource="org/springframework/boot/logging/logback/file-appender.xml" />
	<root level="INFO">
		<appender-ref ref="CONSOLE" />
		<appender-ref ref="FILE" />
	</root>
</included>

部分设置（引入base.xml）
src/main/resources/application.properties

src/main/resources/logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <include resource="org/springframework/boot/logging/logback/base.xml"/>
    <logger name="com.rensanning.springboot" level="WARN" additivity="false">
        <appender-ref ref="CONSOLE"/>
        <appender-ref ref="FILE"/>
    </logger>
</configuration>

启动应用后访问 http://localhost:8080/。

控制台输出内容：

文件输出内容：


使用<springProfile>
src/main/resources/application.properties

src/main/resources/logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <include resource="org/springframework/boot/logging/logback/base.xml" />
    <springProfile name="dev,staging">
        <logger name="com.rensanning.springboot" level="DEBUG" additivity="false">
            <appender-ref ref="CONSOLE" />
        </logger>
    </springProfile>
    <springProfile name="production">
        <logger name="com.rensanning.springboot" level="WARN" additivity="false">
            <appender-ref ref="FILE" />
        </logger>
    </springProfile>
</configuration>

添加VM参数 -Dspring.profiles.active=dev 启动应用后访问 http://localhost:8080/。

文件没有输出，而控制台输出内容：


添加VM参数 -Dspring.profiles.active=production 启动应用后访问 http://localhost:8080/。

控制台没有输出，而文件输出内容：


使用<if><then><else>
Logback通过Janino包还支持在配置文件中条件判断。 http://janino-compiler.github.io/janino/

<dependency>
   <groupId>org.codehaus.janino</groupId>
   <artifactId>janino</artifactId>
   <version>2.7.8</version>
</dependency>

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <include resource="org/springframework/boot/logging/logback/base.xml" />
    <if condition='property("spring.profiles.active").contains("dev")'>
        <then>
            <logger name="com.rensanning.springboot" level="DEBUG" additivity="false">
                <appender-ref ref="CONSOLE" />
            </logger>
        </then>
        <else>
            <logger name="com.rensanning.springboot" level="WARN" additivity="false">
                <appender-ref ref="FILE" />
            </logger>
        </else>
    </if>
</configuration>

使用Log4J 2

pom.xml


src/main/resources/log4j2-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<Configuration monitorInterval="60">
    <Properties>
        <Property name="log-path">d:</Property>
    </Properties>
    <Appenders>
        <Console name="Console-Appender" target="SYSTEM_OUT">
            <PatternLayout>
                <pattern>
                    [%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n
                </pattern>>
            </PatternLayout>
        </Console>
        <File name="File-Appender" fileName="${log-path}/springboot_log.log" >
            <PatternLayout>
                <pattern>
                    [%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n
                </pattern>
            </PatternLayout>
        </File>
    </Appenders>
    <Loggers>
        <Logger name="com.rensanning.springboot" level="info" additivity="false">
            <AppenderRef ref="Console-Appender"/>
        </Logger>
        <Root>
            <AppenderRef ref="File-Appender"/>
            <AppenderRef ref="Console-Appender"/>
        </Root>
    </Loggers>
</Configuration>

启动应用后访问 http://localhost:8080/。

控制台输出内容：