Java — Logback / SLF4J

The com.loginformant:logback-appender Maven artifact adds a Logback appender that batches and ships logs to LogInformant. Works with Spring Boot, plain Java 11+, and any project that uses SLF4J as its logging facade.

1 Add the dependency

xml — Maven pom.xml

<dependency>
  <groupId>com.loginformant</groupId>
  <artifactId>logback-appender</artifactId>
  <version>1.0.0</version>
</dependency>

groovy — Gradle build.gradle

implementation 'com.loginformant:logback-appender:1.0.0'

2 Configure in logback.xml

Add the appender to your src/main/resources/logback.xml:

xml — logback.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>

  <appender name="LOGINFORMANT" class="com.loginformant.LogInformantAppender">
    <apiUrl>https://app.loginformant.com</apiUrl>
    <apiKey>YOUR-API-KEY-HERE</apiKey>
    <!-- Optional -->
    <batchSize>50</batchSize>
    <flushIntervalMs>2000</flushIntervalMs>
  </appender>

  <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%d{HH:mm:ss} %-5level %logger{36} - %msg%n</pattern>
    </encoder>
  </appender>

  <root level="INFO">
    <appender-ref ref="LOGINFORMANT" />
    <appender-ref ref="CONSOLE" />
  </root>

</configuration>

3 Log in your code (SLF4J)

java

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class OrderService {
    private static final Logger log = LoggerFactory.getLogger(OrderService.class);

    public void placeOrder(int orderId) {
        log.info("Order {} placed", orderId);

        try {
            // your logic
        } catch (Exception e) {
            log.error("Failed to place order {}", orderId, e);
        }
    }
}

Spring Boot integration

In Spring Boot, rename the file to logback-spring.xml to support Spring property injection:

xml — logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <springProperty name="LI_API_KEY" source="loginformant.api-key"/>

  <appender name="LOGINFORMANT" class="com.loginformant.LogInformantAppender">
    <apiUrl>https://app.loginformant.com</apiUrl>
    <apiKey>${LI_API_KEY}</apiKey>
  </appender>

  <root level="INFO">
    <appender-ref ref="LOGINFORMANT" />
  </root>
</configuration>

Then in application.properties:

properties

loginformant.api-key=YOUR-API-KEY-HERE

In production, override the property via an environment variable: LOGINFORMANT_API_KEY=your-key with the Spring spring.config.import=optional:file:.env[.properties] pattern, or via your deployment platform's secrets manager.

MDC (Structured Context)

Use SLF4J's MDC to attach key-value context to every log event. All MDC values are forwarded to LogInformant as properties:

java

import org.slf4j.MDC;

public void processPayment(String userId, String requestId) {
    MDC.put("userId", userId);
    MDC.put("requestId", requestId);

    try {
        log.info("Processing payment");
        // your logic
    } finally {
        MDC.clear(); // always clear in a finally block
    }
}

Log level mapping

Logback	LogInformant
TRACE	Debug
DEBUG	Debug
INFO	Information
WARN	Warning
ERROR	Error