I18nMessageHelper is an abstract classes which affords the basic interface for handling messages:

There are also two extended classes from I18nMessageHelper, which afford more flexible message functionalities especially about formatting message by given parameters. Configuration#setI18nMessageHelper can be used to customized which helper you want to use. The default is OrderedParamI18nMessageHelper. (I18nMessageHelperTypeAssistant#getConfiguredMappedHelper and I18nMessageHelperTypeAssistant#getConfiguredOrderedHelper can be used to retrieve a type safe configured helper.)

There are several value formatter can be used by the above helpers. Notice that The MappedParamI18nMessageHelper requires implementation of MappedValueFormatter and the OrderedParamI18nMessageHelper requires implementation of OrderedValueFormatter.

The I18nMessageHelper requires a MessagePatternRetriever implementation to retrieve message by key. There is a default implementation JDKResourceBundleMessagePatternRetriever which uses the JDK's built-in resource bundle mechanism. The base name of resource bundle files can be specified by JDKResourceBundleMessagePatternRetriever#setResourceNames which accepts a list of base name. The configured resource bundles will be passed to JDK's ResourceBundle#getBundle(String baseName, Locale locale, ClassLoader loader) to retrieve messages.

As the implementation of JDKResourceBundleMessagePatternRetriever, if the given locale is null, the default locale decision mechanism will be performed. See Section 15.1.3, “Default locale”.

Further, the JDKResourceBundleMessagePatternRetriever accepts ResourceBundleFactory to allow customize how to retrieve a resource bundle. The default is CharsetResourceBundleFactory which allows specify the encoding of message bundle files. Another built-in implementation is the LatinEscapingResourceBundleFactory, as the name suggests, the message files must be escaped by JDK's standard mechanism(via native2ascii).

The default locale will be decided by the following order and stop at the first non-null returned value.

Since the Locale.getDefault() will return the local machine's locale by default, you may need to override the default locale to ROOT at the staring of your web application.

"afd:msg" tag can be used to declare an i18n aware message in a template file. The basic usage is as following:

<section>
    <article>
        <div class="panel panel-default"><div class="panel-body">
            <!-- the inner html will be treated as default message if the key is not found in message bundle -->
            <afd:msg id="notexistingkey" key="sample.notexistingkey" p0="parameter works as well.">text here to be treated as default message.{0}</afd:msg><br/>
        </div></div>
        
        <div class="panel panel-default"><div class="panel-body">
            <!-- simply specify parameters on tag -->
            <afd:msg id="peoplecount" key="sample.peoplecount" p0="4">dummy text</afd:msg><br/>
            <afd:msg id="peoplecount" key="sample.peoplecount" p0="7" locale="ja_JP">dummy text</afd:msg><br/>
        </div></div>
        
        <div class="panel panel-default"><div class="panel-body">
            <!-- the parameter can be rendered by snippet too -->
            <afd:snippet render="ComplicatedSnippet:setMsgParam">
                <afd:msg id="peoplecount" key="sample.peoplecount" p0="4">dummy text</afd:msg><br/>
                <afd:msg id="peoplecount" key="sample.peoplecount" p0="7" locale="ja_JP">dummy text</afd:msg><br/>
            </afd:snippet>
        </div></div>
        
        <div class="panel panel-default"><div class="panel-body">
            <!-- attribute started with "@" will be treated as a key -->
            <afd:msg id="weatherreport" key="sample.weatherreport" @p0="sample.weatherreport.sunny">天気</afd:msg><br/>
            <afd:msg id="weatherreport" key="sample.weatherreport" @p0="sample.weatherreport.sunny" locale="ja_JP">天気</afd:msg><br/>
        </div></div>
        
        <div class="panel panel-default"><div class="panel-body">
            <!-- attribute started with "#" will be treated as a sub key of current key, thus sample.weatherreport.sunny will be searched -->
            <afd:msg id="weatherreport" key="sample.weatherreport" #p0="rain">天気</afd:msg><br/>
            <afd:msg id="weatherreport" key="sample.weatherreport" #p0="rain" locale="ja_JP">天気</afd:msg><br/>
        </div></div>
        
        <div class="panel panel-default"><div class="panel-body">
            <!-- treat message as text -->
            <afd:msg key="sample.textUrl"></afd:msg><br/>
            
            <!-- treat message as html -->
            <afd:msg key="sample.htmlUrl"></afd:msg><br/>
            
            <!-- treat message as text even it begins with html: -->
            <afd:msg key="sample.escapedUrl"></afd:msg><br/>
        </div></div>
    </article>
</section>

      

public Renderer setMsgParam() {
    Renderer render = Renderer.create();
    render.add("#peoplecount", "p0", 15);
    return render;
}

    

There are something need to be explained: