SLF4J Logback教程

柔光的暖阳◎ 2023-02-15 05:06 129阅读 0赞

![登录徽标][format_png]![登录徽标][format_png]

一个带有[Logback][]示例的简单[SLF4J][] 。

经过测试

*  SLF4J API 1.7.25
 *  回退1.2.3
 *  Maven 3
 *  Java 8

> **注意**  
> Logback本机实现SLF4J API。

## 1.项目目录 ##

![项目目录][format_png 1]![项目目录][format_png 1]

## 2. Maven ##

2.1声明`logback-classic` ，它将`slf4j-api` `logback-core`和`slf4j-api`

pom.xml

<dependency>
    		<groupId>ch.qos.logback</groupId>
    		<artifactId>logback-classic</artifactId>
    		<version>1.2.3</version>
    	</dependency>

com.mkyong:slf4j-logback:jar:1.0
    [INFO] +- ch.qos.logback:logback-classic:jar:1.2.3:compile
    [INFO] |  +- ch.qos.logback:logback-core:jar:1.2.3:compile
    [INFO] |  \- org.slf4j:slf4j-api:jar:1.7.25:compile

2.2完整的`pom.xml`示例。

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
             http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.mkyong</groupId>
        <artifactId>slf4j-logback</artifactId>
        <version>1.0</version>
    
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <java.version>1.8</java.version>
            <logback.version>1.2.3</logback.version>
    		<javax.mail.version>1.6.2</javax.mail.version>
        </properties>
    
        <dependencies>
    
            
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
                <version>${logback.version}</version>
            </dependency>
    
            
    		
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>3.8.0</version>
                    <configuration>
                        <source>${java.version}</source>
                        <target>${java.version}</target>
                    </configuration>
                </plugin>
    
                
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-shade-plugin</artifactId>
                    <version>3.2.0</version>
                    <executions>
                        
                        <execution>
                            <phase>package</phase>
                            <goals>
                                <goal>shade</goal>
                            </goals>
                            <configuration>
                                <transformers>
                                    <transformer
                                            implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                        <mainClass>com.mkyong.HelloWorld</mainClass>
                                    </transformer>
                                </transformers>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>
    
            </plugins>
        </build>
    
    </project>

## 3. logback.xml ##

3.1在项目类路径中创建`logback.xml` 。

src/resources/logback.xml

<?xml version="1.0" encoding="UTF-8"?>
    <configuration>
    
        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
            <layout class="ch.qos.logback.classic.PatternLayout">
                <Pattern>
                    %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n
                </Pattern>
            </layout>
        </appender>
    
        <logger name="com.mkyong" level="debug" additivity="false">
            <appender-ref ref="CONSOLE"/>
        </logger>
    
        <root level="error">
            <appender-ref ref="CONSOLE"/>
        </root>
    
    </configuration>

## 4.你好登录 ##

HelloWorld.java

package com.mkyong;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    public class HelloWorld {
    
        private static final Logger logger = LoggerFactory.getLogger(HelloWorld.class);
    
        public static void main(String[] args) {
    
            logger.debug("Hello from Logback");
    
            logger.debug("getNumber() : {}", getNumber());
    
        }
    
        static int getNumber() {
            return 5;
        }
    
    }

输出量

11:28:18.350 [main] DEBUG com.mkyong.HelloWorld - Hello from Logback
    11:28:18.352 [main] DEBUG com.mkyong.HelloWorld - getNumber() : 5

## 5.登录配置 ##

5.1对于开发，建议启用调试模式。 它会显示很多有用的信息，如果有的话也会显示错误信息。

logback.xml

阅读此[Logback配置][Logback 1]

## 6. Logback Appenders ##

一些常见的Logback附加程序。

6.1 `ConsoleAppender`

logback.xml

<configuration>
    
        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
            <layout class="ch.qos.logback.classic.PatternLayout">
                <Pattern>
                    %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n
                </Pattern>
            </layout>
        </appender>
    
        <logger name="com.mkyong" level="debug" additivity="false">
            <appender-ref ref="CONSOLE"/>
        </logger>
    
        <root level="error">
            <appender-ref ref="CONSOLE"/>
        </root>
    
    </configuration>

6.2 `FileAppender`

logback.xml

<configuration>
    
        <property name="HOME_LOG" value="logs/app.log"/>
    
        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
            <layout class="ch.qos.logback.classic.PatternLayout">
                <Pattern>
                    %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n
                </Pattern>
            </layout>
        </appender>
    
        <appender name="FILE" class="ch.qos.logback.core.FileAppender">
            <file>${HOME_LOG}</file>
            <append>true</append>
            <immediateFlush>true</immediateFlush>
            <encoder>
                <pattern>%d %p %c{1.} [%t] %m%n</pattern>
            </encoder>
        </appender>
    
        <logger name="com.mkyong" level="debug" additivity="false">
            <appender-ref ref="CONSOLE"/>
            <appender-ref ref="FILE"/>
        </logger>
    
        <root level="error">
            <appender-ref ref="CONSOLE"/>
        </root>
    
    </configuration>

logs/app.log

2019-03-29 11:42:44,827 DEBUG com.mkyong.HelloWorld [main] Hello from Logback
    2019-03-29 11:42:44,836 DEBUG com.mkyong.HelloWorld [main] getNumber() : 5

6.3 `RollingFileAppender` –按日期和大小旋转日志文件。 这是您生产中最需要的一种。

logback.xml

<configuration>
    
        <property name="HOME_LOG" value="logs/app.log"/>
    
        <appender name="FILE-ROLLING" class="ch.qos.logback.core.rolling.RollingFileAppender">
            <file>${HOME_LOG}</file>
    
            <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
                <fileNamePattern>logs/archived/app.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
                
                <maxFileSize>10MB</maxFileSize>
                
                <totalSizeCap>20GB</totalSizeCap>
                
                <maxHistory>60</maxHistory>
            </rollingPolicy>
    
            <encoder>
                <pattern>%d %p %c{1.} [%t] %m%n</pattern>
            </encoder>
        </appender>
    
        <logger name="com.mkyong" level="debug" additivity="false">
            <appender-ref ref="FILE-ROLLING"/>
        </logger>
    
        <root level="error">
            <appender-ref ref="FILE-ROLLING"/>
        </root>
    
    </configuration>

![样品][format_png 2]![样品][format_png 2]

![样品][format_png 3]![样品][format_png 3]

添加一个`.gz`扩展名，Logback将压缩存档文件。

logback.xml

<rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
    		<fileNamePattern>logs/archived/app.%d{yyyy-MM-dd}.%i.log.gz</fileNamePattern>
    	</rollingPolicy>

![样品][format_png 4]![样品][format_png 4]

6.4 `SMTPAppender` –需要`javax.mail`来发送电子邮件。

pom.xml

<dependency>
    		<groupId>com.sun.mail</groupId>
    		<artifactId>javax.mail</artifactId>
    		<version>1.6.2</version>
    	</dependency>

logback.xml

<configuration debug="true">
    
        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
            <layout class="ch.qos.logback.classic.PatternLayout">
                <Pattern>
                    %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n
                </Pattern>
            </layout>
        </appender>
    
        <appender name="EMAIL" class="ch.qos.logback.classic.net.SMTPAppender">
            <smtpHost>smtp.mailgun.org</smtpHost>
            <smtpPort>25</smtpPort>
            <username>123</username>
            <password>123</password>
            <to>TO_EMAIL</to>
            <to>RO_ANOTHER_EMAIL</to>
            <from>FROM_EMAIL</from>
            <subject>TESTING: %logger{20} - %m</subject>
    
            <layout class="ch.qos.logback.classic.html.HTMLLayout"/>
    
    		
            <cyclicBufferTracker class="ch.qos.logback.core.spi.CyclicBufferTracker">
    			
                <bufferSize>1</bufferSize>
            </cyclicBufferTracker>
    
    		
            <asynchronousSending>false</asynchronousSending>
    
        </appender>
    
        <logger name="com.mkyong" level="error" additivity="false">
            <appender-ref ref="EMAIL"/>
        </logger>
    
        <root level="error">
            <appender-ref ref="CONSOLE"/>
        </root>
    
    </configuration>

模拟错误

package com.mkyong;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    
    public class HelloWorldError {
    
        private static final Logger logger = LoggerFactory.getLogger(HelloWorldError.class);
    
        public static void main(String[] args) {
    
            try {
                System.out.println(getData());
            } catch (IllegalArgumentException e) {
                logger.error("{}", e);
            }
    
        }
    
        static int getData() throws IllegalArgumentException {
            throw new IllegalArgumentException("Sorry IllegalArgumentException!");
        }
    
    }

这是电子邮件

![样本电子邮件][format_png 5]![样本电子邮件][format_png 5]

6.5 `AsyncAppender` –异步，更快地记录日志，但如果其队列已满80％，则丢弃TRACE，DEBUG和INFO级事件，仅保留WARN和ERROR级事件。 阅读此[AsyncAppender][]

pom.xml

<configuration debug="true">
    
        <property name="HOME_LOG" value="logs/app.log"/>
    
        <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
            <layout class="ch.qos.logback.classic.PatternLayout">
                <Pattern>
                    %d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n
                </Pattern>
            </layout>
        </appender>
    
        <appender name="FILE-ROLLING" class="ch.qos.logback.core.rolling.RollingFileAppender">
            <file>${HOME_LOG}</file>
    
            <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">
                <fileNamePattern>logs/archived/app.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
                
                <maxFileSize>10MB</maxFileSize>
                
                <totalSizeCap>20GB</totalSizeCap>
                
                <maxHistory>60</maxHistory>
            </rollingPolicy>
    
            <encoder>
                <pattern>%d %p %c{1.} [%t] %m%n</pattern>
            </encoder>
        </appender>
    
        
        
        <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
            <appender-ref ref="FILE-ROLLING" />
            
            <queueSize>512</queueSize>
        </appender>
    
        <logger name="com.mkyong" level="debug" additivity="false">
            <appender-ref ref="ASYNC"/>
            <appender-ref ref="CONSOLE"/>
        </logger>
    
        <root level="error">
            <appender-ref ref="CONSOLE"/>
        </root>
    
    </configuration>

> **注意**  
> 阅读更多[Logback附加程序][Logback 2]

## 下载源代码 ##

> $ git clone [https://github.com/mkyong/java-logging.git][https_github.com_mkyong_java-logging.git]  
> $ cd slf4j-logback  
> $ mvn清洁包  
> $ java -jar target \\ slf4j-logback-1.0.jar

## 参考文献 ##

*  [Java的简单日志记录外观（SLF4J）][SLF4J]
 *  [登录项目][Logback]
 *  [Logback Appenders][Logback 2]

标签： [logback][] [日志记录][Link 1] [slf4j][]

> 翻译自: [https://mkyong.com/logging/slf4j-logback-tutorial/][https_mkyong.com_logging_slf4j-logback-tutorial]

[format_png]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL2xvZ2JhY2stbG9nby1iaWcuanBn?x-oss-process=image/format,png
[Logback]: https://logback.qos.ch/
[SLF4J]: https://www.slf4j.org/
[format_png 1]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NsZjRqLWxvZ2JhY2stcHJvamVjdC5wbmc?x-oss-process=image/format,png
[Logback 1]: https://logback.qos.ch/manual/configuration.html
[format_png 2]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NsZjRqLWxvZ2JhY2stZmlsZS1yb2xsaW5nLTEucG5n?x-oss-process=image/format,png
[format_png 3]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NsZjRqLWxvZ2JhY2stZmlsZS1yb2xsaW5nLTIucG5n?x-oss-process=image/format,png
[format_png 4]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NsZjRqLWxvZ2JhY2stZmlsZS1yb2xsaW5nLTMucG5n?x-oss-process=image/format,png
[format_png 5]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NsZjRqLWxvZ2JhY2stZW1haWwucG5n?x-oss-process=image/format,png
[AsyncAppender]: https://logback.qos.ch/manual/appenders.html#AsyncAppender
[Logback 2]: https://logback.qos.ch/manual/appenders.html
[https_github.com_mkyong_java-logging.git]: https://github.com/mkyong/java-logging.git
[logback]: https://mkyong.com/tag/logback/
[Link 1]: https://mkyong.com/tag/logging/
[slf4j]: https://mkyong.com/tag/slf4j/
[https_mkyong.com_logging_slf4j-logback-tutorial]: https://mkyong.com/logging/slf4j-logback-tutorial/