How to use a simple string template in java

Using Apache Commons Lang for simple string templates

The simpliest way to have a string template in java is by using the Apache Commons Lang library which you already have as a dependency already.

Get library

Resolve the dependency through maven by defining it in your pom.xml.

<dependency>
  <groupId>org.apache.commons</groupId>
  <artifactId>commons-lang3</artifactId>
  <version>3.8.1</version>
</dependency>

String template usage

To use the string template approach from Apache Commons Lang library, you first define your data with a Map. Then, you develop your template via a simple string or load it from a file. The template format is very similar to Kotlin String Templates, Velocity or Freemarker. The values are defined with the syntax ${map_key}.

Example:

 Map<String, String> valuesMap = new HashMap<String, String>();
 valuesMap.put("name", "John Doe");
 String templateString = "Welcome ${name}.";
 StrSubstitutor sub = new StringSubstitutor(valuesMap);
 String resolvedString = sub.replace(templateString);

This is a great way for setting up a string template for testing or one off templates within your application.