Log4jInvocation.java

/*
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2026, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v2.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package org.dummy;

import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.PatternLayout;
import ch.qos.logback.classic.spi.ILoggingEvent;
import org.apache.log4j.Logger;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.slf4j.LoggerFactory;

import static org.junit.jupiter.api.Assertions.assertEquals;

/**
 * Used to test log4j-over-slf4j
 * 
 * @author Ceki Gulcu
 *
 */
public class Log4jInvocation {

    static final String HELLO = "Hello";

    DummyLBAppender listAppender;
    LoggerContext lc;
    ch.qos.logback.classic.Logger rootLogger;

    @BeforeEach
    public void fixture() {
        lc = (LoggerContext) LoggerFactory.getILoggerFactory();
        lc.reset();

        listAppender = new DummyLBAppender();
        listAppender.setContext(lc);
        listAppender.start();
        rootLogger = lc.getLogger("root");
        rootLogger.addAppender(listAppender);
    }

    @Test
    public void basic() {
        assertEquals(0, listAppender.list.size());

        Logger logger = Logger.getLogger("basic-test");
        logger.debug(HELLO);

        assertEquals(1, listAppender.list.size());
        ILoggingEvent event = (ILoggingEvent) listAppender.list.get(0);
        assertEquals(HELLO, event.getMessage());
    }

    @Test
    public void callerData() {
        assertEquals(0, listAppender.list.size());

        PatternLayout pl = new PatternLayout();
        pl.setPattern("%-5level [%class] %logger - %msg");
        pl.setContext(lc);
        pl.start();
        listAppender.layout = pl;

        Logger logger = Logger.getLogger("basic-test");
        logger.trace("none");
        assertEquals(0, listAppender.list.size());

        rootLogger.setLevel(Level.TRACE);
        logger.trace(HELLO);
        assertEquals(1, listAppender.list.size());

        ILoggingEvent event = (ILoggingEvent) listAppender.list.get(0);
        assertEquals(HELLO, event.getMessage());

        assertEquals(1, listAppender.stringList.size());
        assertEquals("TRACE [" + Log4jInvocation.class.getName() + "] basic-test - Hello",
                listAppender.stringList.get(0));
    }
}