Dinesh on Java

Default Logging Format in Spring Boot

2016-07-24 20:31:45.280  INFO 10220 --- [           main] c.d.SpringBootHelloWorldApplication      : Starting SpringBootHelloWorldApplication on NODTBSL206AG with PID 10220 (started by Dinesh.Rajput in D:personal dataspring-boot-workspaceSpringBootHelloWorld)
2016-07-24 20:31:45.286  INFO 10220 --- [           main] c.d.SpringBootHelloWorldApplication      : No active profile set, falling back to default profiles: default
2016-07-24 20:31:45.502  INFO 10220 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@1809907: startup date [Sun Jul 24 20:31:45 IST 2016]; root of context hierarchy
2016-07-24 20:31:48.201  INFO 10220 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat initialized with port(s): 8080 (http)
2016-07-24 20:31:48.226  INFO 10220 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2016-07-24 20:31:48.228  INFO 10220 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/8.5.3
2016-07-24 20:31:48.485  INFO 10220 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2016-07-24 20:31:48.485  INFO 10220 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 2993 ms

Create Spring Boot Maven Project

<?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.dineshonjava</groupId>
 <artifactId>SpringBootHelloWorld</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>jar</packaging>

 <name>SpringBootHelloWorld</name>
 <description>SpringBootHelloWorld project for Spring Boot</description>

 <parent>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-parent</artifactId>
  <version>1.4.0.RC1</version>
  <relativePath/> <!-- lookup parent from repository -->
 </parent>

 <properties>
  <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  <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-test</artifactId>
   <scope>test</scope>
  </dependency>
 </dependencies>
 
 <build>
  <plugins>
   <plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
   </plugin>
  </plugins>
 </build>
</project>

package com.dineshonjava;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@SpringBootApplication
public class SpringBootHelloWorldApplication {
 
private static final Logger logger = LoggerFactory.getLogger(SpringBootHelloWorldApplication.class);
 

@RequestMapping("/")
    String home() {
        return "Hello World!";
    }
 
public static void main(String[] args) {
    SpringApplication.run(SpringBootHelloWorldApplication.class, args);
    logger.error("Message logged at ERROR level");
    logger.warn("Message logged at WARN level");
    logger.info("Message logged at INFO level");
    logger.debug("Message logged at DEBUG level");
}
}

2016-07-24 20:57:40.828 ERROR 3024 --- [           main] c.d.SpringBootHelloWorldApplication      : Message logged at ERROR level
2016-07-24 20:57:40.828  WARN 3024 --- [           main] c.d.SpringBootHelloWorldApplication      : Message logged at WARN level
2016-07-24 20:57:40.828  INFO 3024 --- [           main] c.d.SpringBootHelloWorldApplication      : Message logged at INFO level

Customizing default Configuration for Logging:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <!-- Log message format -->
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
      </pattern>
    </encoder>
  </appender>

  <!-- Setting the root level of logging to INFO -->
  <root level="info">
    <appender-ref ref="STDOUT" />
  </root>
</configuration>

21:14:46.352 [main] ERROR c.d.SpringBootHelloWorldApplication - Message logged at ERROR level
21:14:46.352 [main] WARN  c.d.SpringBootHelloWorldApplication - Message logged at WARN level
21:14:46.352 [main] INFO  c.d.SpringBootHelloWorldApplication - Message logged at INFO level

Printing Logs into a File:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <!-- Log message format -->
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>
  <!-- Need appender to write to file -->
  <appender name="FILE" class="ch.qos.logback.core.FileAppender">
    <!-- Name of the file where the log messages are written -->
    <file>MySpringBootApp.log</file>
    <encoder>
      <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>
  <logger name="com.dineshonjava.service" level="warn">
    <appender-ref ref="FILE" />
  </logger>

  <!-- Setting the root level of logging to INFO -->
  <root level="info">
    <appender-ref ref="FILE" />
  </root>
</configuration>

package com.dineshonjava.service;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class HelloService {
private Logger logger = LoggerFactory.getLogger(HelloService.class);
public void service(){
  logger.info("Message at INFO level from HelloService.service()");
  logger.warn("Message at WARN level from HelloService.service()");
}
}

Custom log configuration

1. Logback -> logback-spring.xml, logback-spring.groovy, logback.xml or logback.groovy
2. Log4j2 -> log4j2-spring.xml or log4j2.xml
3. JDK (Java Util Logging) -> logging.properties

1. logging.file -> Used in default log configuration if defined for logging file name.
2. logging.path -> Used in default log configuration if defined for logging file path of directory.
3. logging.pattern.console -> The log pattern to use on the console.
4. logging.pattern.file -> The log pattern to use in a file.
5. logging.pattern.level -> The format to use to render the log level.
6. logging.exception-conversion-word -> The conversion word that’s used when logging exceptions.

Summary