Velocity template - message key instead the whole phrase with placeholders

Question

I have email template .vm which contains msg with message key from messages_en.properties:

#msg("email-body")

messages_en.properties has:

email-body = Hello, $name!

After:

private String buildMessage(String templateName, Properties properties, Locale locale) {

    Template template = getVelocityEngine().getTemplate(templateName);

    VelocityContext context = new VelocityContext();

    for (String key : properties.stringPropertyNames()) {
        context.put(key, properties.getProperty(key));
    }

    context.put(LocaleDirective.MESSAGES_LOCALE, locale);

    StringWriter writer = new StringWriter();
    template.merge(context, writer);

    return writer.toString();
}

I get:

Hello, $name!

And name isn't replaced with actual value.

What's the best way to manage phrases in email template? I want to put only message key in the template, not the whole phrase with placeholder.

Answer 1

Use evaluate directive for substitute variable inside of other variable:

import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.RuntimeSingleton;
import org.apache.velocity.runtime.parser.node.SimpleNode;

import java.io.StringReader;
import java.io.StringWriter;

public class Main {

    public static void main(String[] args) throws Exception {
        RuntimeServices runtimeServices = RuntimeSingleton.getRuntimeServices();
        StringReader reader = new StringReader("#evaluate($email-body)");
        SimpleNode node = runtimeServices.parse(reader, "default");

        Template template = new Template();
        template.setRuntimeServices(runtimeServices);
        template.setData(node);
        template.initDocument();


        VelocityContext context = new VelocityContext();
        context.put("name", "Maxim");
        context.put("email-body", "Hello, $name!");

        StringWriter writer = new StringWriter();
        template.merge(context, writer);

        System.out.println(writer.toString());
    }
}

Output:

Hello, Maxim!