wildling

Java library and CLI for pattern-based string generation. Zero third-party dependencies (JDK standard library only). Targets Java 11+.

Docs: Website · Sandbox · Syntax · Source

Registry: Maven Central

Example

http://${'dev,stage,prod'}\-${'api,web'}#{0-2}.example.${'com,net,org'}/@.html

(The \- is a literal hyphen; bare - would mean “one letter or digit”. @ is one lowercase letter.)

That builds URL-shaped candidates: scheme http://, then environment × service × optional digits × TLD, then a one-letter path page. Three environments, two services, zero–two digits ('', 0–9, 00–99), three TLDs, and a–z → 51948 strings — the kind of list you generate for fuzzing links or probing staging hosts, not type out.

A few of them:

http://dev-api.example.com/a.html / http://stage-web.example.com/z.html
http://dev-api0.example.net/a.html / http://prod-web9.example.org/m.html
http://dev-api00.example.com/a.html / http://prod-web99.example.org/z.html

Named dictionaries (%{'hosts'}) work the same way when the word lists live in files.

Try it in the sandbox, or see pattern syntax for length ranges, dictionaries, and escapes.

Install

From this repository:

cd java
./build.sh
./bin/wildling "Year 19##"

From a release tag:

git clone --branch v2.0.0 --depth 1 https://github.com/dotmonk/wildling.git
cd wildling
./build.sh java

Registry: Maven Central (when published)

Produces dist/wildling.jar. Requires a JRE to run (java -jar), or Docker (the launcher falls back to the Temurin image if java is not on PATH).

As a library, add dist/wildling.jar to your classpath:

import wildling.Wildling;
import java.util.List;
import java.util.Map;

Wildling wildling = Wildling.create(List.of("Year 19##"), Map.of());
Object value = wildling.next();
while (!Boolean.FALSE.equals(value)) {
    System.out.println(value);
    value = wildling.next();
}

CLI

./bin/wildling "Year 19##"
./bin/wildling --dictionary planets:../dictionaries/planets.txt "%{'planets'}"
./bin/wildling --template ./config.json

Help text and --check output follow docs/cli.md / docs/help.txt.

Build

./build.sh   # Docker (eclipse-temurin): javac + jar, embeds help.txt

Project tests live in ../tests/ and are run with ../test.sh.