last modified October 18, 2023
Spring MessageSource tutorial shows how to translate messages using MessageSource in a Spring application.
Spring is a popular Java application framework for creating enterprise applications.
MessageSource is used for resolving messages, with support for the
parameterization and internationalization of the messages. Spring contains two
built-in MessageSource implementations:
ResourceBundleMessageSource and
ReloadableResourceBundleMessageSource. The latter is able to reload
message definitions without restarting the Virtual Machine.
The following application contains messages in English and German language. It
uses the built-in ResourceBundleMessageSource.
pom.xml src ├───main │ ├───java │ │ └───com │ │ └───zetcode │ │ │ Application.java │ │ └───config │ │ AppConfig.java │ └───resources │ │ logback.xml │ └───messages │ label.properties │ label_de.properties └───test └───java
This is the project structure.
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.zetcode</groupId>
<artifactId>messagesource</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>17</maven.compiler.source>
<maven.compiler.target>17</maven.compiler.target>
<spring-version>5.3.23</spring-version>
</properties>
<dependencies>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.4.0</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring-version}</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<mainClass>com.zetcode.Application</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>
In the pom.xml file, we have basic Spring dependencies spring-core,
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"?>
<configuration>
<logger name="org.springframework" level="ERROR"/>
<logger name="com.zetcode" level="INFO"/>
<appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<Pattern>%d{HH:mm:ss.SSS} %blue(%-5level) %magenta(%logger{36}) - %msg %n
</Pattern>
</encoder>
</appender>
<root>
<level value="INFO" />
<appender-ref ref="consoleAppender" />
</root>
</configuration>
The logback.xml is a configuration file for the Logback logging library.
l1=Earth
l2=Hello {0}, how are you?
These are English messages. The second property receives a parameter.
l1=Erde
l2=Hallo {0}, wie geht's?
These are German messages.
package com.zetcode.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
@Configuration
public class AppConfig {
@Bean
public ResourceBundleMessageSource messageSource() {
var source = new ResourceBundleMessageSource();
source.setBasenames("messages/label");
source.setUseCodeAsDefaultMessage(true);
return source;
}
}
The AppConfig configures the ResourceBundleMessageSource.
The setBasenames tells where to look for message definitions.
package com.zetcode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.MessageSource;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import java.util.Locale;
@ComponentScan(basePackages = "com.zetcode")
public class Application {
private static final Logger logger = LoggerFactory.getLogger(Application.class);
@Autowired
private MessageSource messageSource;
public static void main(String[] args) {
var ctx = new AnnotationConfigApplicationContext(Application.class);
var app = ctx.getBean(Application.class);
app.run();
ctx.close();
}
public void run() {
logger.info("Translated messages:");
logger.info("{}", messageSource.getMessage("l1",
null, Locale.GERMAN));
logger.info("{}", messageSource.getMessage("l1",
null, Locale.ENGLISH));
logger.info("Translated parameterized messages:");
logger.info("{}", messageSource.getMessage("l2",
new Object[] {"Paul Smith"}, Locale.GERMAN));
logger.info("{}", messageSource.getMessage("l2",
new Object[] {"Paul Smith"}, Locale.ENGLISH));
}
}
The application prints plain messages and parameterized messages to the console.
@Autowired private MessageSource messageSource;
We inject the MessageSource, which was generated in AppConfig.
logger.info("{}", messageSource.getMessage("l1",
null, Locale.GERMAN));
The getMessage takes the property name as the first parameter. The
second parameter is null, because the messsage takes no parameters.
The third parameter is the locale.
logger.info("{}", messageSource.getMessage("l2",
new Object[] {"Paul Smith"}, Locale.GERMAN));
Here we also provide a parameter to the message.
$ mvn -q exec:java 22:08:27.984 INFO com.zetcode.Application - Translated messages: 22:08:27.984 INFO com.zetcode.Application - Erde 22:08:27.984 INFO com.zetcode.Application - Earth 22:08:27.984 INFO com.zetcode.Application - Translated parameterized messages: 22:08:27.984 INFO com.zetcode.Application - Hallo Paul Smith, wie gehts? 22:08:27.984 INFO com.zetcode.Application - Hello Paul Smith, how are you?
We run the application.
In this article we have shown how to use ResourceBundleMessageSource
in a Spring application.
My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.
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