Java generating Strings with placeholders

StrSubstitutor from Apache Commons Lang may be used for string formatting with named placeholders:

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-text</artifactId>
    <version>1.1</version>
</dependency>

https://commons.apache.org/proper/commons-lang/javadocs/api-3.4/org/apache/commons/lang3/text/StrSubstitutor.html :

Substitutes variables within a string by values.

This class takes a piece of text and substitutes all the variables within it. The default definition of a variable is ${variableName}. The prefix and suffix can be changed via constructors and set methods.

Variable values are typically resolved from a map, but could also be resolved from system properties, or by supplying a custom variable resolver.

Example:

String template = "Hi ${name}! Your number is ${number}";

Map<String, String> data = new HashMap<String, String>();
data.put("name", "John");
data.put("number", "1");

String formattedString = StrSubstitutor.replace(template, data);

See String.format method.

String s = "hello %s!";
s = String.format(s, "world");
assertEquals(s, "hello world!"); // should be true