You create a simple definition of the template engine that uses the default resource loader as follows:

<objects xmlns="http://www.springframework.net" xmlns:nv="http://www.springframework.net/nvelocity">

  <!-- Simple no arg file based configuration use's NVeclocity default file resource loader  -->
  <nv:engine id="velocityEngine" />

</objects>

The velocity engine could then be used to load and merge a local template using a simple relative path (the default resource loader path is the current execution directory):

StringWriter stringWriter = new StringWriter();
Hashtable modelTable = new Hashtable();
modelTable.Add("var1", TEST_VALUE);
VelocityContext velocityContext = new VelocityContext(modelTable);
velocityEngine.MergeTemplate("Template/Velocity/MyTemplate.vm", Encoding.UTF8.WebName, velocityContext, stringWriter);
string mergedContent = stringWriter.ToString();

To disable the use of NVelocity's file loader that tracks runtime changes, set the element prefer-file-system-access of <engine/> to false.

You can define several attributes on the <engine> element to control how the factory is configured:

When templates are packaged in an assembly, NVelocity's assembly resource loader can be used to define where templates reside:

<nv:engine id="velocityEngine" >
    <nv:resource-loader>
        <nv:assembly name="MyAssembly" />
    </nv:resource-loader>
</nv:nvelocity>

Using the example above the template would be loaded using a namespace syntax for the template resource:

velocityEngine.MergeTemplate("MyAssembly.MyNamespace.MyTemplate.vm", Encoding.UTF8.WebName, velocityContext, stringWriter);

In some cases Spring's IResource abstraction can be beneficial to load templates from a variety of resources. A Spring IResource loader extension to the NVelocity resource loader implementation is provided for this use case. The following object definition loads the NVelocity templates from a single path

<nv:engine id="velocityEngine">
  <nv:resource-loader>
    <nv:spring uri="file://Template/Velocity/"/>
  </nv:resource-loader>
</nv:engine>

Or with multiple locations

<nv:engine id="velocityEngine">
  <nv:resource-loader>
    <nv:spring uri="file://Template/Velocity/"/>
    <nv:spring uri="assembly://MyAssembly/MyNameSpace"/>
  </nv:resource-loader>
</nv:engine>

	Note
	By default spring will attempt to load resources using NVelocity's file based template loading (useful for detection of template changes at runtime). If this is not desirable you set the prefer-file-system-access property of the factory object to false which will cause the factory to utilize the supplied spring resource loader.

Using the example above when resource loader paths are defined templates can be loaded using their name:

string mergedTemplate = VelocityEngineUtils.MergeTemplateIntoString(velocityEngine, "MyFileTemplate.vm", Encoding.UTF8.WebName, model); // template loaded from file://Template/Velocity/
string mergedTemplate = VelocityEngineUtils.MergeTemplateIntoString(velocityEngine, "MyAssemblyTemplate.vm", Encoding.UTF8.WebName, model); // template loaded from assembly://MyAssembly/MyNameSpace

The following defines a custom resource loader (the type is an extension of NVelocity's ResourceLoader class):

<nv:engine id="velocityEngine">
    <nv:resource-loader>
        <nv:custom name="myResourceLoader" 
                   description="A custom resource loader" 
                   type="MyNamespace.MyResourceLoader, MyAssembly"  
                   path="Template/Velocity/"/>
    </nv:resource-loader>
</nv:engine>

The <nv:resource-loader> element has additional attributes which define how NVelocity's resource manager and resource loader behave.

If so desired one could provide a custom configuration resource to customize the NVelocity configuration:

<nv:engine id="velocityEngine" config-file="file://Template/Velocity/config.properties"/>

You can override specific properties by providing the VelocityProperties property to the NVelocity factory object (shown above)

<nv:engine id="velocityTemplate" >
  <nv:nvelocity-properties>
    <entry key="input.encoding"  value="ISO-8859-1"/>
    <entry key="output.encoding" value="ISO-8859-1"/>
  </nv:nvelocity-properties>
</nv:engine>

By default Spring will override NVelocity's default ILogSystem implementation with its own CommonsLoggingLogSystem implementation so that the logging stream of NVelocity will go to the same logging subsystem that Spring uses. If this is not desirable, you can specify the following property of the NVelocity factory object:

<template:nvelocity id="velocityEngine" override-logging="false" />