Spring c-namespace tutorial

last modified October 18, 2023

Spring constructor namespace tutorial shows how to use c-namespace in constructor-based injection in a Spring application.

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

Spring c-namespace

Spring c-namespace is an XML shortcut and replacement of the <constructor-arg/> subelement of the <bean/> tag. To enable the c-namespace feature, we need to add the xmlns:c="http://www.springframework.org/schema/c" into the XML file. Note that this namespace does not have a separate XSD file; therefore, IDEs such as IntelliJ do not recognize it.

Spring c-namespace example

The application contains two User beans. One is injected with the older <constructor-arg/>, the other one with the newer c-namespace attribute.

│   ├───java
│   │   └───com
│   │       └───zetcode
│   │           │   Application.java
│   │           └───bean
│   │                   User.java
│   └───resources
│           logback.xml
│           my-beans.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} %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.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"

    <bean name="user1" class="com.zetcode.bean.User">
        <constructor-arg name="name" value="John Doe"/>
        <constructor-arg name="occupation" value="gardener"/>

    <bean name="user2" class="com.zetcode.bean.User"
            c:name="Peter Smith" c:occupation="teacher"/>


The my-beans.xml file declares two beans: user1 and user2. The user1 uses <constructor-arg/> to inject its values, while user2 uses c:name and c:occupation attributes.

package com.zetcode.bean;

public class User {

    private String name;
    private String occupation;

    public User(String name, String occupation) {
        this.name = name;
        this.occupation = occupation;

    public String toString() {

        final var sb = new StringBuilder("User{");
        sb.append(", occupation='").append(occupation).append('\'');
        return sb.toString();

This is the User class that is managed by Spring container. It must contain a constructor because we use constructor-based injection in our application.

package com.zetcode;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.support.GenericXmlApplicationContext;

public class Application {

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

    public static void main(String[] args) {

        var ctx = new GenericXmlApplicationContext("my-beans.xml");

        var u1 = ctx.getBean("user1");
        var u2 = ctx.getBean("user2");

        logger.info("{}", u1);
        logger.info("{}", u2);


This is the main application class. It retrieves the two beans and prints them to the console.

$ mvn -q exec:java
16:40:39.632 INFO  com.zetcode.Application - User{name='John Doe', occupation='gardener'} 
16:40:39.632 INFO  com.zetcode.Application - User{name='Peter Smith', occupation='teacher'} 

We run the application.

In this article we have shown how to use constructor-based injection with c-namespace.


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.

List all Spring tutorials.