Receive all server errors/exceptions as email, never miss one, easy to share and discuss with the others

Follow these simple steps to configure Log4j to use GMail.


Step 1: Add dependencies

        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>mail</artifactId>
            <version>1.4</version>
        </dependency>
       
        <!-- Log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.16</version>
            <exclusions>
                <exclusion>
                    <groupId>javax.mail</groupId>
                    <artifactId>mail</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>javax.jms</groupId>
                    <artifactId>jms</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jdmk</groupId>
                    <artifactId>jmxtools</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>com.sun.jmx</groupId>
                    <artifactId>jmxri</artifactId>
                </exclusion>
            </exclusions>
        </dependency>


Step 2: Sample logging file, inline comments are self explanatory
        file linke : https://github.com/intesar/Log4jGmail/blob/master/src/main/resources/log4j.xml

    <?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
    <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
        
        <!-- Appends events to console : compliments SMTPAppender -->
        <appender name="Console" class="org.apache.log4j.ConsoleAppender">
            <layout class="org.apache.log4j.PatternLayout">
                <param name="ConversionPattern" value="[${name}] - %d{ISO8601} - %X{login} - %m%n" />
            </layout>
        </appender>

        <!-- SMTP will only log error events -->
        <appender name="Email" class="org.apache.log4j.net.SMTPAppender">
            <param name="BufferSize" value="1" /> <!-- default is 512, changed for test cases to work -->
            <!-- GMail will not work without this, log4j 1.2.16 is required this why earlier versions required hack-->
            <param name="SMTPProtocol" value="smtps" /> 
            <param name="SMTPHost" value="smtp.gmail.com" />
            <param name="SMTPPort" value="465" />
            <param name="SMTPUsername" value="<email>" /> <!-- [email protected] -->
            <param name="SMTPPassword" value="<passowrd>" /> <!-- passowrd -->
            <param name="To" value="[email protected]" />
            <param name="Subject" value="Zytoon.me Error Log" />
            <layout class="org.apache.log4j.PatternLayout">
                <param name="ConversionPattern" value="[${name}] - %d{ISO8601} - %X{login} - %m%n" />
            </layout>
        </appender>

        <appender name="EMAIL_ASYNC" class="org.apache.log4j.AsyncAppender">
            <param name="BufferSize" value="1"/>
            <appender-ref ref="Email"/>
        </appender>

        <root>
            <priority value="trace" />
            <appender-ref ref="EMAIL_ASYNC" />
            <appender-ref ref="Console" />
        </root>

    </log4j:configuration>


Sample Code 

    import org.apache.log4j.Logger;

    public class App {

        private static Logger logger = Logger.getLogger(App.class);

        public static void main(String[] args) throws InterruptedException {

            logger.trace("trace message");

            logger.warn("warn message");
            
            // if you want this to pass change appender to Email instead of ASYNC_EMAIL in root logger
            logger.error("error message, a very long error message!");

        }
    }