Log4j JDBCAppender – Create Logs in Database

Log4j is a simple and flexible logging framework. Logging equips the developer with detailed context for application failures. With log4j it is possible to enable logging at runtime without modifying the application binary. The log4j package is designed so that these statements can remain in shipped code without incurring a heavy performance cost.

Log4j comes with multiple options to format log files created by framework. It can create simple log files, html log files or xml log files also. It also insert log statements into database also, using mysql statements.

This this post, I am showing the example code for configuring log4j to produce logs in database table.

Step 1) Create a maven java project and update log4j dependencies

Follow the steps given in this post related to configuring log4j with maven.

Step 2) Configure JDBCAppender in log4j.properties file

The JDBCAppender provides mechanism for sending log events to a database tables. Each append call adds to an ArrayList buffer. When the buffer is filled each log event is placed in a sql statement (configurable) and executed. BufferSize, db URL, User, & Password are configurable options in the standard log4j ways.

WARNING: This version of JDBCAppender is very likely to be completely replaced in the future. Moreoever, it does not log exceptions.

# Define the root logger with file appender
log4j.rootLogger = DEBUG, sql

# Define the file appender
log4j.appender.sql=org.apache.log4j.jdbc.JDBCAppender
log4j.appender.sql.URL=jdbc:mysql://localhost/test
# Set Database Driver
log4j.appender.sql.driver=com.mysql.jdbc.Driver
# Set database user name and password
log4j.appender.sql.user=root
log4j.appender.sql.password=password
# Set the SQL statement to be executed.
log4j.appender.sql.sql=INSERT INTO LOGS VALUES ('%x', now() ,'%C','%p','%m')
# Define the xml layout for file appender
log4j.appender.sql.layout=org.apache.log4j.PatternLayout

Step 3) Create the table in database and test the application

Create the database table LOGS, in schema test.

CREATE TABLE LOGS
(
	USER_ID VARCHAR(20) NOT NULL,
	DATED   DATETIME NOT NULL,
	LOGGER  VARCHAR(50) NOT NULL,
	LEVEL   VARCHAR(10) NOT NULL,
	MESSAGE VARCHAR(1000) NOT NULL
);

Now, configure the log4j.properties file using PropertyConfigurator and call some log events.

package com.howtodoinjava;

import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;

public class Log4jJDBCExample
{
	static Logger log = Logger.getLogger(Log4jJDBCExample.class);

	public static void main(String[] args)
	{
		PropertyConfigurator.configure("log4j.properties");

		log.debug("Sample debug message");
		log.info("Sample info message");
		log.error("Sample error message");
		log.fatal("Sample fatal message");
	}
}

Log statements will be inserted in database using sql statement.

Let me know if any question.

Happy Learning !!