Hello guys, Bushan here, Welcome back to B2 Tech. Today in this post, I will show you how to configure/implement Logger using SLF4J in Spring MVC/Java Application. So let’s begin,
Table of Contents
Tools and Technologies used,
- JDK 1.8.0_121
- Eclipse Oxygen
- SLF4J 1.7.12
- Maven
- Spring 4.2.1.RELEASE
Project Structure
Jar dependencies
Edit the pom.xml file and add slf4j dependencies in it as follows.
pom.xml
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.arpit.java2blog</groupId>
<artifactId>SpringMVCHibernateCRUDExample</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>SpringMVCHibernateCRUDExample Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
<!-- Bridge logging from JCL to SLF4j -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>${jcl.slf4j.version}</version>
</dependency>
<!-- logback -->
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${logback.version}</version>
</dependency>
</dependencies>
<build>
<finalName>SpringMVCHibernateCRUDExample</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<spring.version>4.2.1.RELEASE</spring.version>
<jdk.version>1.7</jdk.version>
<logback.version>1.1.3</logback.version>
<jcl.slf4j.version>1.7.12</jcl.slf4j.version>
</properties>
</project>
XML configuration file for SLF4J
Create a logback.xml file under the src/main/resources source folder and write the following code in it.
logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<property name="LOG_HOME" value="D:/Logs/" />
<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<Pattern>%date %level [%thread] %logger %msg%n</Pattern>
</encoder>
</appender>
<appender name="FILE"
class="ch.qos.logback.core.rolling.RollingFileAppender">
<File>${LOG_HOME}/logger.log</File>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<FileNamePattern>
${LOG_HOME}/apitracker-%d.%i.log.gz
</FileNamePattern>
<TimeBasedFileNamingAndTriggeringPolicy
class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<MaxFileSize>10MB</MaxFileSize>
</TimeBasedFileNamingAndTriggeringPolicy>
</rollingPolicy>
<encoder>
<Pattern>%date %level [%thread] %logger %msg%n</Pattern>
</encoder>
</appender>
<!-- By default, the level of the root level is set to DEBUG -->
<root level="DEBUG">
<appender-ref ref="CONSOLE" />
<appender-ref ref="FILE" />
</root>
</configuration>
Console Appender – Writes the logs to either System.out or System.err
File Appender – Writes the logs to the File named in the <File> tag.
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <display-name>Archetype Created Web Application</display-name> <servlet> <servlet-name>spring</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>spring</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> </web-app>
spring-servlet.xml
<?xml version="1.0" encoding="UTF-8"?> <beans:beans xmlns="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd"> <annotation-driven /> <resources mapping="/resources/**" location="/resources/" /> <beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <beans:property name="prefix" value="/WEB-INF/views/" /> <beans:property name="suffix" value=".jsp" /> </beans:bean> <context:component-scan base-package="in.bushansirgur" /> </beans:beans>
HomeController.java
package in.bushansirgur.controller;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class HomeController {
private static final Logger logger = LoggerFactory.getLogger(HomeController.class);
@RequestMapping("/")
public String homePage() {
logger.info("This is logger info::::::");
logger.debug("This is logger debug:::::");
logger.error("This is logger error");
return "home";
}
}
home.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<h1>This is home page</h1>
</body>
</html>
After running the application the console output and file D:/Logs/logger.log will look like as follows.
2018-10-28 11:52:26,130 DEBUG [http-nio-8037-exec-2] org.springframework.web.servlet.DispatcherServlet DispatcherServlet with name 'spring' processing GET request for [/SpringMVCHibernateCRUDExample/] 2018-10-28 11:52:26,140 DEBUG [http-nio-8037-exec-2] org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping Looking up handler method for path / 2018-10-28 11:52:26,152 DEBUG [http-nio-8037-exec-2] org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping Returning handler method [public java.lang.String in.bushansirgur.controller.HomeController.homePage()] 2018-10-28 11:52:26,153 DEBUG [http-nio-8037-exec-2] org.springframework.beans.factory.support.DefaultListableBeanFactory Returning cached instance of singleton bean 'homeController' 2018-10-28 11:52:26,157 DEBUG [http-nio-8037-exec-2] org.springframework.web.servlet.DispatcherServlet Last-Modified value for [/SpringMVCHibernateCRUDExample/] is: -1 2018-10-28 11:52:26,227 INFO [http-nio-8037-exec-2] in.bushansirgur.controller.HomeController This is logger info:::::: 2018-10-28 11:52:26,227 DEBUG [http-nio-8037-exec-2] in.bushansirgur.controller.HomeController This is logger debug::::: 2018-10-28 11:52:26,227 ERROR [http-nio-8037-exec-2] in.bushansirgur.controller.HomeController This is logger error
