VelocityUtils.java

import org.apache.velocity.Template;
import org.apache.velocity.VelocityContext;
import org.apache.velocity.app.VelocityEngine;

import java.io.StringWriter;
import java.util.Properties;

public class VelocityUtils {
    public static String generateContent(String templatePath,
                                         VelocityContext context) {
        return generateContent(templatePath, context, VelocityUtils.class.getClassLoader());
    }

    public static String generateContent(String templatePath,
                                         VelocityContext context,
                                         ClassLoader classLoader) {
        ClassLoader oldClsLoader = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader(classLoader);
        Properties props = new Properties();
        props.setProperty("resource.loader", "class");
        props.setProperty("class.resource.loader.class",
                          "org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader");
        VelocityEngine ve = new VelocityEngine(props);
        ve.init();
        Template tp = ve.getTemplate(templatePath, "UTF-8");
        StringWriter writer = new StringWriter();
        tp.merge(context, writer);
        Thread.currentThread().setContextClassLoader(oldClsLoader);
        return writer.toString();
    }
}