Locale and Internationalization in Spring MVC

Create Spring MVC Project

On the Eclipse, create a Spring MVC project in Spring Boot

Enter Project Information:

• Name: LearnSpringMVCWithRealApps
• Group: com.demo
• Artifact: LearnSpringMVCWithRealApps
• Description: Learn Spring MVC with Real Apps
• Package: com.demo

Select the technologies and libraries to be used:

• Web

Click Next button to show Site Information for project

Click Finish button to finish create Spring MVC project

Configure pom.xml

<?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.demo</groupId>
	<artifactId>LearnSpringMVCWithRealApps</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>LearnSpringMVCWithRealApps</name>
	<description>Learn Spring MVC with Real Apps</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.2.RELEASE</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>

		<!-- Spring MVC  -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<!-- JSTL tag lib -->
		<dependency>
			<groupId>javax.servlet.jsp.jstl</groupId>
			<artifactId>javax.servlet.jsp.jstl-api</artifactId>
			<version>1.2.1</version>
		</dependency>

		<dependency>
			<groupId>taglibs</groupId>
			<artifactId>standard</artifactId>
			<version>1.1.2</version>
		</dependency>

		<!-- Tomcat for JSP rendering -->
		<dependency>
			<groupId>org.apache.tomcat.embed</groupId>
			<artifactId>tomcat-embed-jasper</artifactId>
			<scope>provided</scope>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

Message Sources

Create new properties file in src\main\resources folder as below:

messages.properties

greeting=Hello! How are you today?

messages_en.properties

greeting=Hello! How are you today?

messages_fr.properties

greeting=Salut! Comment vas-tu aujourd'hui?

messages_de.properties

greeting=Hallo! Wie geht es Ihnen heute?

Configure application.properties

spring.mvc.view.prefix = /WEB-INF/views/
spring.mvc.view.suffix = .jsp
spring.mvc.static-path-pattern=/resources/**

server.port=9596

Configure Spring MVC

package com.demo;

import java.util.Locale;
import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ResourceBundleMessageSource;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.i18n.SessionLocaleResolver;

@Configuration
public class SpringMVCConfiguration extends WebMvcConfigurerAdapter {

	@Bean
	public MessageSource messageSource() {
		ResourceBundleMessageSource resourceBundleMessageSource = new ResourceBundleMessageSource();
		resourceBundleMessageSource.setBasename("messages");
		return resourceBundleMessageSource;
	}

	@Bean
	public SessionLocaleResolver localeResolver() {
		SessionLocaleResolver sessionLocaleResolver = new SessionLocaleResolver();
		sessionLocaleResolver.setDefaultLocale(Locale.US);
		return sessionLocaleResolver;
	}

	@Bean
	public LocaleChangeInterceptor localeChangeInterceptor() {
		LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
		localeChangeInterceptor.setParamName("lang");
		return localeChangeInterceptor;
	}

	@Override
	public void addInterceptors(InterceptorRegistry interceptorRegistry) {
		interceptorRegistry.addInterceptor(localeChangeInterceptor());
	}

}

Create Controller

Create new package named com.demo.controllers. In this package, create new controller named DemoController as below:

package com.demo.controllers;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
@RequestMapping("demo")
public class DemoController {

	@RequestMapping(method = RequestMethod.GET)
	public String index() {
		return "demo/index";
	}

}

Create View

Create new folders with path webapp\WEB-INF\views in src\main. In views folder, create new folder named demo. In demo folder, create new JSP Pages as below:

Index View

Create new jsp file named index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="s" uri="http://www.springframework.org/tags"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Demo Page</title>
</head>
<body>

	<a href="${pageContext.request.contextPath }/demo?lang=en">English</a> |
	<a href="${pageContext.request.contextPath }/demo?lang=fr">French</a> |
	<a href="${pageContext.request.contextPath }/demo?lang=de">German</a>
	<br>
	<s:message code="greeting"></s:message>

</body>
</html>

Structure of Spring MVC Project

Run Application

Select LearnSpringMVCWithRealAppsApplication.java file in com.demo package, right click and select Run As/Spring Boot App menu

Access index method in demo controller with following url: http://localhost:9596/demo

Output

Select French menu to change content to French language with following url: http://localhost:9596/demo?lang=fr

Output

Select German menu to change content to German language with following url: http://localhost:9596/demo?lang=de

Output

References

I recommend you refer to the books below to learn more about the knowledge in this article:

• Spring MVC Beginners Guide – Second Edition
• Spring MVC Cookbook
• Spring MVC Blueprints
• Mastering Spring MVC 4
• Spring Boot in Action
• Pro Spring Boot