Spring @Qualifier annotation tutorial

last modified October 18, 2023

Spring @Qualifier annotation tutorial shows how to use @Qualifier to differentiate beans in a Spring application.

Spring is a popular Java application framework for creating enterprise applications.

Spring @Qualifier annotation

The @Qualifier annotation helps disambiguate bean references when Spring would otherwise not be able to do so.

Spring @Qualifier example

The application has different types of message beans. We differentiate between them with @Qualifier.

│   ├───java
│   │   └───com
│   │       └───zetcode
│   │           │   Application.java
│   │           ├───bean
│   │           │       IMessage.java
│   │           │       Info.java
│   │           │       Warning.java
│   │           └───service
│   │                   MessageProducer.java
│   └───resources
│           logback.xml

This is the project structure.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"










In the pom.xml file, we have basic Spring dependencies spring-core and spring-context and logging logback-classic dependency.

The exec-maven-plugin is used for executing Spring application from the Maven on the command line.

<?xml version="1.0" encoding="UTF-8"?>
    <logger name="org.springframework" level="ERROR"/>
    <logger name="com.zetcode" level="INFO"/>

    <appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender">
            <Pattern>%d{HH:mm:ss.SSS} [%thread] %blue(%-5level) %magenta(%logger{36}) - %msg %n

        <level value="INFO" />
        <appender-ref ref="consoleAppender" />

The logback.xml is a configuration file for the Logback logging library.

package com.zetcode.bean;

public interface IMessage {

    String getMessage();

The IMessage interface has one method declaration.

package com.zetcode.bean;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;

public class Info implements IMessage {

    public String getMessage() {

        return "This is an information message";

The first implementation of the interface gives an information message. The @Qualifier is used to identify the bean.

package com.zetcode.bean;

import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;

public class Warning implements IMessage {

    public String getMessage() {

        return "This is a warning message";

The second implementation gives a warning message. It is also named with the @Qualifier.

package com.zetcode.service;

import com.zetcode.bean.IMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

public class MessageProducer {

    private static final Logger logger = LoggerFactory.getLogger(MessageProducer.class);

    private IMessage infoMessage;

    private IMessage warningMessage;

    public void produce() {

        logger.info("{}", infoMessage.getMessage());
        logger.warn("{}", warningMessage.getMessage());

The MessageProducer injects two IMessage beans. To differentiate between them, we use @Qualifier annotations.

package com.zetcode;

import com.zetcode.service.MessageProducer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;

@ComponentScan(basePackages = "com.zetcode.bean;com.zetcode.service")
public class Application {

    private static final Logger logger = LoggerFactory.getLogger(Application.class);

    public static void main(String[] args) {

        logger.info("Application starting");

        try (var ctx = new AnnotationConfigApplicationContext(Application.class)) {

            var messageProducer = (MessageProducer) ctx.getBean("messageProducer");

This is the main application class. It retrieves the messageProducer bean and call its produce method.

$ mvn -q exec:java
10:50:03.309 [com.zetcode.Application.main()] INFO  com.zetcode.Application - Application starting
10:50:03.574 [com.zetcode.Application.main()] INFO  com.zetcode.service.MessageProducer - This is an information message
10:50:03.574 [com.zetcode.Application.main()] WARN  com.zetcode.service.MessageProducer - This is a warning message

We run the application.

In this article we have worked with Spring's @Qualifier annotation.


My name is Jan Bodnar and I am a passionate programmer with many years of programming experience. I have been writing programming articles since 2007. So far, I have written over 1400 articles and 8 e-books. I have over eight years of experience in teaching programming.

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