Spring, Mustache Starter - translations - spring

Question

I try to configure my project to support internationalization.
I wrote simple configuration based on configuration for JSP that I used recently.
import org.springframework.context.MessageSource;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.support.ReloadableResourceBundleMessageSource;
import org.springframework.core.env.Environment;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.i18n.CookieLocaleResolver;
import org.springframework.web.servlet.i18n.LocaleChangeInterceptor;
import org.springframework.web.servlet.view.mustache.java.LocalizationMessageInterceptor;
import javax.inject.Inject;
import java.util.Locale;
#Configuration
public class AppConfig extends WebMvcConfigurerAdapter {
#Inject
private Environment environment;
private static final String[] CLASSPATH_RESOURCE_LOCATIONS = new String[]{
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"
};
#Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/resources/**").addResourceLocations(CLASSPATH_RESOURCE_LOCATIONS);
}
/* Internationalization beans */
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(localeChangeInterceptor());
}
#Bean
public LocaleChangeInterceptor localeChangeInterceptor(){
LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
localeChangeInterceptor.setParamName("language");
return localeChangeInterceptor;
}
#Bean(name = "localeResolver")
public LocaleResolver getLocaleResolver(){
CookieLocaleResolver localeResolver = new CookieLocaleResolver();
localeResolver.setDefaultLocale(new Locale(environment.getProperty("system.default.language")));
return localeResolver;
}
#Bean
public MessageSource messageSource() {
final ReloadableResourceBundleMessageSource ret = new ReloadableResourceBundleMessageSource();
ret.setBasename("classpath:translations");
ret.setDefaultEncoding("UTF-8");
ret.setUseCodeAsDefaultMessage(true);
return ret;
}
#Bean
#Inject
public LocalizationMessageInterceptor getLocalizationMessageInterceptor(MessageSource messageSource, LocaleResolver localeResolver) {
LocalizationMessageInterceptor lmi = new LocalizationMessageInterceptor();
lmi.setLocaleResolver(localeResolver);
lmi.setMessageSource(messageSource);
return lmi;
}
}
In html files I cannot access translation values.
${app.name}
is not resolved,
{{app.name}}
causes an exception
No method or field with name 'app'
Translation files are placed under resources catalogue, default language is set:
system.default.language=en
EDIT:
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.example.gateway</groupId>
<artifactId>gateway-application</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Gateway Application</name>
<description>Gateway Application Project</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.0.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>
<spring-webmvc-pac4j.version>1.1.1</spring-webmvc-pac4j.version>
<pac4j.version>1.9.1</pac4j.version>
<javax.inject.version>1</javax.inject.version>
<apache-commons.version>3.4</apache-commons.version>
<spring-devtools.version>1.4.0.RELEASE</spring-devtools.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mustache</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.github.sps.mustache</groupId>
<artifactId>mustache-spring-view</artifactId>
<version>1.3</version>
</dependency>
<!-- PAC4J -->
<dependency>
<groupId>org.pac4j</groupId>
<artifactId>pac4j-cas</artifactId>
<version>${pac4j.version}</version>
</dependency>
<dependency>
<groupId>org.pac4j</groupId>
<artifactId>pac4j-http</artifactId>
<version>${pac4j.version}</version>
</dependency>
<dependency>
<groupId>org.pac4j</groupId>
<artifactId>spring-webmvc-pac4j</artifactId>
<version>${spring-webmvc-pac4j.version}</version>
<exclusions>
<exclusion>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Inject -->
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>${javax.inject.version}</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>${apache-commons.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Brixton.SR4</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Spring Boot 1.4.0.RELEASE

Answer 1

I did some unnecessary configuration. Short summarisation in 4 points.
AppConfig.java
#Configuration
public class AppConfig extends WebMvcConfigurerAdapter {
#Inject
private Environment environment;
#Inject
private MessageSource messageSource;
/* Internationalization beans */
#Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(localeChangeInterceptor());
registry.addInterceptor(getLocalizationMessageInterceptor());
}
#Bean
public LocaleChangeInterceptor localeChangeInterceptor(){
LocaleChangeInterceptor localeChangeInterceptor = new LocaleChangeInterceptor();
localeChangeInterceptor.setParamName("language");
return localeChangeInterceptor;
}
#Bean(name = "localeResolver")
public LocaleResolver getLocaleResolver(){
CookieLocaleResolver localeResolver = new CookieLocaleResolver();
localeResolver.setDefaultLocale(new Locale(environment.getProperty("system.default.language")));
return localeResolver;
}
#Bean
public LocalizationMessageInterceptor getLocalizationMessageInterceptor() {
LocalizationMessageInterceptor lmi = new LocalizationMessageInterceptor();
lmi.setLocaleResolver(getLocaleResolver());
lmi.setMessageSource(messageSource);
return lmi;
}
}
As #M. Deinum said MessageSource and resource configuration is done by starters so we don't need it.
pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-mustache</artifactId>
</dependency>
<dependency>
<groupId>com.github.sps.mustache</groupId>
<artifactId>mustache-spring-view</artifactId>
<version>1.3</version>
</dependency>
mustache-spring-view is needed because of org.springframework.web.servlet.view.mustache.jmustache.LocalizationMessageInterceptor.
message.properties
For default locale (en) file message.properties is required.
For different locale file message_LOCALE.properties is used.
Those files should be placed under resources/.
HTML files
Message values can be accessed in HTML file with notation
{{#i18n}}message-key{{/i18n}}