Spring Boot Log4j 2示例

古城微笑少年丶 2023-02-15 05:16 77阅读 0赞

![Spring启动log4j 2][Spring_log4j 2]![Spring启动log4j 2][Spring_log4j 2]

在本教程中，我们将向您展示如何在Spring Boot框架中使用[Apache Log4j 2][] 。

使用的技术：

*  Spring Boot 2.1.2发布
 *  Spring5.1.4。发布
 *  Log4j 2.11.1
 *  Maven 3
 *  Java 8

## 1.项目目录 ##

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

## 2. Maven ##

关键是排除默认的`logback` ，并在`spring-boot-starter-log4j2`包含`log4j`

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>
    
        <artifactId>logging-log4j2</artifactId>
        <packaging>jar</packaging>
        <name>Spring Boot log4j2 Example</name>
        <url>https://www.mkyong.com</url>
        <version>1.0</version>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.2.RELEASE</version>
        </parent>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <dependencies>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-thymeleaf</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
                <exclusions>
                    <exclusion>
                        <groupId>org.springframework.boot</groupId>
                        <artifactId>spring-boot-starter-logging</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-log4j2</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>com.lmax</groupId>
                <artifactId>disruptor</artifactId>
                <version>3.4.2</version>
            </dependency>
    
            
            
            
    
            <dependency>
                <groupId>com.fasterxml.jackson.dataformat</groupId>
                <artifactId>jackson-dataformat-yaml</artifactId>
            </dependency>
    
        </dependencies>
    
        <build>
            <plugins>
                
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
    
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <version>2.22.0</version>
                </plugin>
    
            </plugins>
        </build>
    </project>

显示项目依赖项。

$ mvn dependency:tree
    
    [INFO] \- org.springframework.boot:spring-boot-starter-log4j2:jar:2.1.2.RELEASE:compile
    [INFO]    +- org.apache.logging.log4j:log4j-slf4j-impl:jar:2.11.1:compile <--- slf4j to log4j bridge
    [INFO]    |  \- org.apache.logging.log4j:log4j-api:jar:2.11.1:compile
    [INFO]    +- org.apache.logging.log4j:log4j-core:jar:2.11.1:compile
    [INFO]    +- org.apache.logging.log4j:log4j-jul:jar:2.11.1:compile
    [INFO]    \- org.slf4j:jul-to-slf4j:jar:1.7.25:compile

$ mvn dependency:tree
    
    [INFO] org.springframework.boot:logging-log4j2:jar:1.0
    [INFO] +- org.springframework.boot:spring-boot-starter-web:jar:2.1.2.RELEASE:compile
    [INFO] |  +- org.springframework.boot:spring-boot-starter-json:jar:2.1.2.RELEASE:compile
    [INFO] |  |  +- com.fasterxml.jackson.core:jackson-databind:jar:2.9.8:compile
    [INFO] |  |  |  \- com.fasterxml.jackson.core:jackson-annotations:jar:2.9.0:compile
    [INFO] |  |  +- com.fasterxml.jackson.datatype:jackson-datatype-jdk8:jar:2.9.8:compile
    [INFO] |  |  +- com.fasterxml.jackson.datatype:jackson-datatype-jsr310:jar:2.9.8:compile
    [INFO] |  |  \- com.fasterxml.jackson.module:jackson-module-parameter-names:jar:2.9.8:compile
    [INFO] |  +- org.springframework.boot:spring-boot-starter-tomcat:jar:2.1.2.RELEASE:compile
    [INFO] |  |  +- org.apache.tomcat.embed:tomcat-embed-core:jar:9.0.14:compile
    [INFO] |  |  +- org.apache.tomcat.embed:tomcat-embed-el:jar:9.0.14:compile
    [INFO] |  |  \- org.apache.tomcat.embed:tomcat-embed-websocket:jar:9.0.14:compile
    [INFO] |  +- org.hibernate.validator:hibernate-validator:jar:6.0.14.Final:compile
    [INFO] |  |  +- javax.validation:validation-api:jar:2.0.1.Final:compile
    [INFO] |  |  +- org.jboss.logging:jboss-logging:jar:3.3.2.Final:compile
    [INFO] |  |  \- com.fasterxml:classmate:jar:1.4.0:compile
    [INFO] |  +- org.springframework:spring-web:jar:5.1.4.RELEASE:compile
    [INFO] |  |  \- org.springframework:spring-beans:jar:5.1.4.RELEASE:compile
    [INFO] |  \- org.springframework:spring-webmvc:jar:5.1.4.RELEASE:compile
    [INFO] |     +- org.springframework:spring-aop:jar:5.1.4.RELEASE:compile
    [INFO] |     +- org.springframework:spring-context:jar:5.1.4.RELEASE:compile
    [INFO] |     \- org.springframework:spring-expression:jar:5.1.4.RELEASE:compile
    [INFO] +- org.springframework.boot:spring-boot-starter-thymeleaf:jar:2.1.2.RELEASE:compile
    [INFO] |  +- org.thymeleaf:thymeleaf-spring5:jar:3.0.11.RELEASE:compile
    [INFO] |  |  +- org.thymeleaf:thymeleaf:jar:3.0.11.RELEASE:compile
    [INFO] |  |  |  +- org.attoparser:attoparser:jar:2.0.5.RELEASE:compile
    [INFO] |  |  |  \- org.unbescape:unbescape:jar:1.1.6.RELEASE:compile
    [INFO] |  |  \- org.slf4j:slf4j-api:jar:1.7.25:compile
    [INFO] |  \- org.thymeleaf.extras:thymeleaf-extras-java8time:jar:3.0.2.RELEASE:compile
    [INFO] +- org.springframework.boot:spring-boot-starter:jar:2.1.2.RELEASE:compile
    [INFO] |  +- org.springframework.boot:spring-boot:jar:2.1.2.RELEASE:compile
    [INFO] |  +- org.springframework.boot:spring-boot-autoconfigure:jar:2.1.2.RELEASE:compile
    [INFO] |  +- javax.annotation:javax.annotation-api:jar:1.3.2:compile
    [INFO] |  +- org.springframework:spring-core:jar:5.1.4.RELEASE:compile
    [INFO] |  |  \- org.springframework:spring-jcl:jar:5.1.4.RELEASE:compile
    [INFO] |  \- org.yaml:snakeyaml:jar:1.23:compile
    [INFO] +- org.springframework.boot:spring-boot-starter-log4j2:jar:2.1.2.RELEASE:compile
    [INFO] |  +- org.apache.logging.log4j:log4j-slf4j-impl:jar:2.11.1:compile
    [INFO] |  |  \- org.apache.logging.log4j:log4j-api:jar:2.11.1:compile
    [INFO] |  +- org.apache.logging.log4j:log4j-core:jar:2.11.1:compile
    [INFO] |  +- org.apache.logging.log4j:log4j-jul:jar:2.11.1:compile
    [INFO] |  \- org.slf4j:jul-to-slf4j:jar:1.7.25:compile
    [INFO] +- com.lmax:disruptor:jar:3.4.2:compile
    [INFO] \- com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:jar:2.9.8:compile
    [INFO]    \- com.fasterxml.jackson.core:jackson-core:jar:2.9.8:compile

## 3. log4j2.xml ##

3.1在项目类路径`src/resources/`创建一个`log4j2.xml`

src/resources/log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
    <Configuration status="DEBUG">
        <Appenders>
            <Console name="LogToConsole" target="SYSTEM_OUT">
                <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
            </Console>
            <File name="LogToFile" fileName="logs/app.log">
                <PatternLayout>
                    <Pattern>%d %p %c{1.} [%t] %m%n</Pattern>
                </PatternLayout>
            </File>
        </Appenders>
        <Loggers>
            <Logger name="com.mkyong" level="debug" additivity="false">
                <AppenderRef ref="LogToFile"/>
                <AppenderRef ref="LogToConsole"/>
            </Logger>
            <Logger name="org.springframework.boot" level="error" additivity="false">
                <AppenderRef ref="LogToConsole"/>
            </Logger>
            <Root level="error">
                <AppenderRef ref="LogToFile"/>
                <AppenderRef ref="LogToConsole"/>
            </Root>
        </Loggers>
    </Configuration>

3.2对于`log4j2.yml` ，我们需要包括`jackson-databind`和`jackson-dataformat-yaml` ，因为`jackson-databind`已经包含在Spring Boot Starter中，所以，我们只需要包括`jackson-dataformat-yaml`

pom.xml

<dependency>
    		<groupId>com.fasterxml.jackson.dataformat</groupId>
    		<artifactId>jackson-dataformat-yaml</artifactId>
    	</dependency>

log4j2.yml

Configuration:
      status: debug
    
      appenders:
        Console:
          name: LogToConsole
          PatternLayout:
            Pattern: "[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n"
    
        RollingFile:
          - name: LogToRollingFile
            fileName: logs/app.log
            filePattern: "logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz"
            PatternLayout:
              pattern: "[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n"
            Policies:
              SizeBasedTriggeringPolicy:
                size: 10MB
            DefaultRollOverStrategy:
              max: 10
    
      Loggers:
        logger:
          - name: com.mkyong
            level: debug
            additivity: false
            AppenderRef:
              - ref: LogToConsole
              - ref: LogToRollingFile
    
        Root:
          level: error
          AppenderRef:
            ref: LogToConsole

## 4.你好log4j2 ##

4.1一个简单的Spring MVC Web应用程序，使用log4j2登录。

HelloController.java

package com.mkyong;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.GetMapping;
    
    import java.util.Arrays;
    import java.util.List;
    
    @Controller
    public class HelloController {
    
        private static final Logger logger = LogManager.getLogger(HelloController.class);
    
        private List<Integer> num = Arrays.asList(1, 2, 3, 4, 5);
    
        @GetMapping("/")
        public String main(Model model) {
    
            // pre-java 8
            if (logger.isDebugEnabled()) {
                logger.debug("Hello from Log4j 2 - num : {}", num);
            }
    
            // java 8 lambda, no need to check log level
            logger.debug("Hello from Log4j 2 - num : {}", () -> num);
    
            model.addAttribute("tasks", num);
            return "welcome"; //view
        }
    
        private int getNum() {
            return 100;
        }
    
    }

4.2模板

src/resources/templates/welcome.html

<!DOCTYPE HTML>
    <html lang="en" xmlns:th="http://www.thymeleaf.org">
    <head></head>
    <body>
    
    <h1>Spring Boot + log4j2 example</h1>
    <ul>
        <li th:each="task : ${tasks}" th:text="${task}"></li>
    </ul>
    
    </body>
    </html>

## 5.演示 ##

5.1启动Spring Boot

StartApplication.java

package com.mkyong;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    @SpringBootApplication
    public class StartApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(StartApplication.class, args);
        }
    
    }

*http：//本地主机：8080*

![演示][format_png 1]![演示][format_png 1]

查看日志：

Terminal

19:10:08.723 [http-nio-8080-exec-1] DEBUG com.mkyong.HelloController - Hello from Log4j 2 - num : [1, 2, 3, 4, 5]
    19:10:08.724 [http-nio-8080-exec-1] DEBUG com.mkyong.HelloController - Hello from Log4j 2 - num : [1, 2, 3, 4, 5]

## 6. Log4j 2 –异步记录器 ##

6.1要启用异步日志记录，我们需要包括`disruptor`

pom.xml

<dependency>
    		<groupId>com.lmax</groupId>
    		<artifactId>disruptor</artifactId>
    		<version>3.4.2</version>
    	</dependency>

6.2设置系统属性`log4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector`

Terminal

$ mvn package 
    
    $ java -Dlog4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector -jar target/logging-log4j2-1.0.jar
    
    019-03-27 19:28:57,185 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3
    2019-03-27 19:28:57,189 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=AsyncLoggerRingBuffer
    2019-03-27 19:28:57,194 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=StatusLogger
    2019-03-27 19:28:57,195 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=ContextSelector
    2019-03-27 19:28:57,195 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=Loggers,name=org.springframework.boot
    2019-03-27 19:28:57,196 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=Loggers,name=
    2019-03-27 19:28:57,196 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=Loggers,name=com.mkyong
    2019-03-27 19:28:57,197 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=Appenders,name=LogToConsole
    2019-03-27 19:28:57,200 main DEBUG Registering MBean org.apache.logging.log4j2:type=AsyncContext@578486a3,component=Appenders,name=LogToFile

## 下载源代码 ##

> $ git clone [https://github.com/mkyong/spring-boot.git][https_github.com_mkyong_spring-boot.git]  
> $ cd logging-log4j2  
> $ mvn spring-boot：运行  
> 访问 *本地主机：8080*
> 
> $ mvn软件包  
> $ java -Dlog4j2.contextSelector = org.apache.logging.log4j.core.async.AsyncLoggerContextSelector -jar target / logging-log4j2-1.0.jar  
> 访问*本地主机：8080*

## 参考文献 ##

*  [Spring Boot日志][Spring Boot]
 *  [Apache Log4j 2][]
 *  Apache Log4j 2教程
 *  [低延迟日志记录的异步记录器][Link 1]

标签： [log4j2][] [记录][Link 2] [弹簧启动][Link 3]

> 翻译自: [https://mkyong.com/spring-boot/spring-boot-log4j-2-example/][https_mkyong.com_spring-boot_spring-boot-log4j-2-example]

[Spring_log4j 2]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NwcmluZy1ib290LWxvZzRqMi1sb2dvLnBuZw?x-oss-process=image/format,png
[Apache Log4j 2]: https://logging.apache.org/log4j/2.x/
[format_png]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NwcmluZy1ib290LWxvZzRqMi1wcm9qZWN0LnBuZw?x-oss-process=image/format,png
[format_png 1]: http://imgconvert.csdnimg.cn/aHR0cHM6Ly9ta3lvbmcuY29tL3dwLWNvbnRlbnQvdXBsb2Fkcy8yMDE5LzAzL3NwcmluZy1ib290LWxvZzRqMi1kZW1vLnBuZw?x-oss-process=image/format,png
[https_github.com_mkyong_spring-boot.git]: https://github.com/mkyong/spring-boot.git
[Spring Boot]: https://docs.spring.io/spring-boot/docs/current/reference/html/howto-logging.html
[Link 1]: https://logging.apache.org/log4j/2.x/manual/async.html
[log4j2]: https://mkyong.com/tag/log4j2/
[Link 2]: https://mkyong.com/tag/logging/
[Link 3]: https://mkyong.com/tag/spring-boot/
[https_mkyong.com_spring-boot_spring-boot-log4j-2-example]: https://mkyong.com/spring-boot/spring-boot-log4j-2-example/