Spring Boot log4j2 example 2018-05-09 06:02
It is easy to use log4j2 in spring boot. Create a maven project, structure like following.
├─main
│ ├─java
│ │ └─com
│ │ └─henryxi
│ │ └─log4j2
│ │ AppConfig.java
│ │ AppController.java
│ │
│ └─resources
│ log4j2.xml
Add the dependency in the pom file. In order to use log4j2 you have to exclusion spring-boot-starter-logging
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</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>
<version>1.3.3.RELEASE</version>
</dependency>
</dependencies>
The content of AppConfig and AppController:
@EnableAutoConfiguration
@Configuration
@ComponentScan("com.henryxi.log4j2")
public class AppConfig extends WebMvcConfigurerAdapter {
private static Logger logger = LoggerFactory.getLogger(AppConfig.class);
public static void main(String[] args) throws Exception {
try {
SpringApplication.run(AppConfig.class, args);
} catch (Exception e) {
logger.error("start error:", e);
}
}
}
@Controller
public class AppController {
private static Logger logger = LoggerFactory.getLogger(AppController.class);
@RequestMapping(value = "/testLog4j2", method = RequestMethod.GET)
@ResponseBody
public String testLog4j2() {
String content = "hello spring boot log4j2.";
logger.info("this is info log!");
logger.error("this is error log!");
logger.warn("this is warm log!");
return content;
}
}
Put log4j2.xml in resources directory.
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN" monitorInterval="30">
<Properties>
<Property name="LOG_PATTERN">
%d{yyyy-MM-dd HH:mm:ss.SSS} %5p ${hostName} --- [%15.15t] %-40.40c{1.} : %m%n%ex
</Property>
</Properties>
<Appenders>
<Console name="ConsoleAppender" target="SYSTEM_OUT" follow="true">
<PatternLayout pattern="${LOG_PATTERN}"/>
</Console>
<File name="FileAppender" fileName="/tmp/spring_boot.log" >
<PatternLayout pattern="${LOG_PATTERN}"/>
</File>
</Appenders>
<Loggers>
<Logger name="com" level="info" additivity="false">
<AppenderRef ref="ConsoleAppender" />
<AppenderRef ref="FileAppender" />
</Logger>
<Root level="info">
<AppenderRef ref="ConsoleAppender" />
<AppenderRef ref="FileAppender" />
</Root>
</Loggers>
</Configuration>
Run the project and access localhost:8080/testLog4j2. The console will output the following log.
2018-05-09 17:56:59.880 INFO henry-PC --- [nio-8080-exec-1] c.h.l.AppController : this is info log!
2018-05-09 17:56:59.880 ERROR henry-PC --- [nio-8080-exec-1] c.h.l.AppController : this is error log!
2018-05-09 17:56:59.880 WARN henry-PC --- [nio-8080-exec-1] c.h.l.AppController : this is warm log!
The content of log is in /tmp/spring_boot.log.
EOF