This is an implementation of the left-pad library with special support for Java 8's Functional paradigm. It is lightweight and supports industrial usage thanks to its 100% test coverage and continuous integration.

It works well with modern libraries like Spring Data and jooq.

At it's heart, left-pad is easy to use and simple to grasp. However, its interface is built on decades of programming language research.

The simplest usage looks like new LeftPad(length, character).apply(string).

It also supports an advanced functional style whereby you define a new LeftPad functor and apply it as a unary function which accepts a CharSequence.

Example:

LeftPad fourPadded = new LeftPad(4);
fourPadded.apply("foo"); // => " foo"
fourPadded.apply("x");   // => "   x"

// using Java 8 Streams
// this will yield [" x", " y", " z"]
asList("x", "y", "z").stream().map(new LeftPad(2)).collect(Collectors.toList())

LeftPad also supports TDD practices since you always create a LeftPad object instance before calling the function. This makes it easy to mock.

You can even use your favorite dependency injection framework to efficiently pass a configured LeftPad object throughout your code without impacting testability.

Clone this repository, run mvn install, and this project as a dependency.

maven:

<dependency>
    <groupId>net.raboof</groupId>
    <artifactId>left-pad</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>

gradle:

compile 'net.raboof:left-pad:1.0-SNAPSHOT'

sbt:

libraryDependencies += "net.raboof" % "left-pad" % "1.0-SNAPSHOT"

Licensed under The Apache License, Version 2.0. See the LICENSE file.