Javanilla

A Java 10+ lightweight utility library to enhance the Java standard API.

Introduction

Javanilla has been made to improve the developer experience with Java, in fact it provides a lot of easy-to-use components for various usages. Its goal is not to replace popular utility libraries such as Apache Commons or Google Guava because it is not as complete or reliable, but Javanilla is composed of some original tools that could be used in complement of them.

Getting started

To include and use Javanilla, you need to add the following dependency from the Maven Central:

Maven (pom.xml)

<dependency>
	<groupId>com.github.alexisjehan</groupId>
	<artifactId>javanilla</artifactId>
	<version>1.8.0</version>
</dependency>

Gradle Groovy (build.gradle)

plugins {
	id 'java-library'
}

repositories {
	mavenCentral()
}

dependencies {
	implementation 'com.github.alexisjehan:javanilla:1.8.0'
}

Gradle Kotlin (build.gradle.kts)

plugins {
	`java-library`
}

repositories {
	mavenCentral()
}

dependencies {
	implementation("com.github.alexisjehan:javanilla:1.8.0")
}

Also, the Javadoc can be accessed here.

Examples

Here are non-exhaustives examples of how you can use Javanilla.

I/O examples

Some InputStream and OutputStream utility tools and decorators:

// Read from an optional InputStream and then from another one which gives 0x00 and 0xff bytes
final var concatInputStream = InputStreams.concat(
		InputStreams.nullToEmpty(optionalInputStream),
		InputStreams.of((byte) 0x00, (byte) 0xff)
);

// Write to both a buffered file OutputStream and a sampling one
final var fromIndex = 0L;
final var toIndex = 100L;
final var teeOutputStream = OutputStreams.tee(
		OutputStreams.buffered(fileOutputStream),
		new RangeOutputStream(sampleOutputStream, fromIndex, toIndex) // Write only the 100 firsts bytes
);

// Wrap the InputStream so that it could be used in a foreach-style loop for a better readability
for (final var i : Iterables.wrap(concatInputStream)) {
	teeOutputStream.write(i);
}
teeOutputStream.flush();

Convert line separators from a Unix file to a Windows one using LineReader and LineWriter:

// Convert a String with Unix line separators to the Windows format removing the extra new line
final var unixFilePath = Readers.of("foo\nbar\n");
final var ignoreTerminatingNewLine = true;
try (var lineReader = new LineReader(unixFilePath, LineSeparator.LF, ignoreTerminatingNewLine)) {
	final var appendTerminatingNewLine = false;
	try (var lineWriter = new LineWriter(windowsFilePath, LineSeparator.CR_LF, appendTerminatingNewLine)) {
		// Transfers all lines from the LineReader to the LineWriter
		final var transferred = lineReader.transferTo(lineWriter);
		System.out.println(transferred); // Prints 2
	}
}

Lang examples

String and CharSequence utility tools:

System.out.println(Strings.blankToEmpty("   ")); // Prints an empty String

System.out.println(Strings.quote("A quoted String with an escaped \" double quote")); // Prints "A quoted String with an escaped \" double quote"

final var size = 5;
final var padding = 'o';
System.out.println(Strings.padLeft("foo", size, padding)); // Prints oofoo

final var suffix = 'o';
System.out.println(Strings.removeEnd("foo", suffix)); // Prints fo

final var target = 'o';
final var replacement = 'r';
System.out.println(Strings.replaceLast("foo", target, replacement)); // Prints for

System.out.println(Strings.concatMerge("Once upon a time […]", "[…] the end")); // Prints Once upon a time […] the end

System.out.println(Strings.isHexadecimal("foo")); // Prints false
System.out.println(Strings.isHexadecimal(ByteArrays.toHexadecimalString("foo".getBytes()))); // Prints true

System.out.println(Strings.isBase64("foo")); // Prints false
System.out.println(Strings.isBase64(Base64.getEncoder().encodeToString("foo".getBytes()))); // Prints true

Throwable utility tools:

// Sleep 5 seconds and throw an unchecked Exception if the thread is interrupted, no try/catch required
final var millis = 5_000L;
ThrowableProcedure.unchecked(() -> Thread.sleep(millis)).execute();

// Still no try/catch required, but this time keep the original checked exception
ThrowableSupplier.sneaky(() -> {
	throw new IOException("A checked Exception inside a lambda");
});

final var exception = new UncheckedIOException(new IOException());
System.out.println(Throwables.isUncheckedException(exception)); // Prints true
System.out.println(Throwables.getOptionalRootCause(exception).orElseThrow().getClass().getName()); // Prints java.io.IOException

Primitive and generic arrays utility tools:

IntArrays.of(1, 2, 3); // Similar to new int[] {1, 2, 3};
ObjectArrays.of("foo", "bar"); // Similar to new String[] {"foo", "bar"};

System.out.println(Arrays.toString(LongArrays.concat(LongArrays.of(1L, 2L, 3L), LongArrays.of(4L, 5L, 6L)))); // Prints [1, 2, 3, 4, 5, 6]
final var separator = CharArrays.singleton(' ');
System.out.println(Arrays.toString(CharArrays.join(separator, "foo".toCharArray(), "bar".toCharArray()))); // Prints [f, o, o,  , b, a, r]

System.out.println(FloatArrays.containsAll(FloatArrays.of(1.0f, 1.0f, 2.0f), 1.0f, 0.0f)); // Prints false
System.out.println(FloatArrays.containsAll(FloatArrays.of(1.0f, 2.0f, 3.0f), 1.0f, 2.0f)); // Prints true
System.out.println(DoubleArrays.indexOf(DoubleArrays.of(1.0d, 2.0d, 3.0d), 1.0d)); // Prints 0
System.out.println(DoubleArrays.indexOf(DoubleArrays.of(1.0d, 2.0d, 3.0d), 0.0d)); // Prints -1

System.out.println(ByteArrays.toHexadecimalString(ByteArrays.concat(ByteArrays.singleton((byte) 0x00), ByteArrays.ofHexadecimalString("ff")))); // Prints 00ff

Misc examples

Print values as pretty strings using StringFormatter:

final var floatPrecision = 3;
final var stringFormatter = new StringFormatter(Locale.US, floatPrecision);

System.out.println(stringFormatter.format(1_234_567L)); // Prints 1,234,567

System.out.println(stringFormatter.formatBytes(1_234_567L)); // Prints 1.177MiB
System.out.println(stringFormatter.formatBytes(1_234_567L, StringFormatter.BytePrefix.SI)); // Prints 1.235MB

final var progression = 1.0d;
final var total = 3.0d;
System.out.println(stringFormatter.formatPercent(progression, total)); // Prints 33.333%

System.out.println(stringFormatter.formatCurrency(123.456789d)); // Prints $123.457

Some Distance and EditDistance calculations:

final var x1 = 0.0d;
final var y1 = 0.0d;
final var x2 = 1.0d;
final var y2 = 2.0d;
System.out.println(Distances.MANHATTAN.calculate(x1, y1, x2, y2)); // Prints 3.0
final var order = 1;
System.out.println(new MinkowskiDistance(order).calculate(x1, y1, x2, y2)); // Prints 3.0
System.out.println(EditDistances.HAMMING.calculate("foo", "for")); // Prints 1.0
System.out.println(LevenshteinDistance.DEFAULT.calculate("append", "apple")); // Prints 3.0

Util examples

New Comparator implementation:

System.out.println(Stream.of("foo2", "foo1", "foo10").sorted().collect(Collectors.toList())); // Prints [foo1, foo10, foo2]
System.out.println(Stream.of("foo2", "foo1", "foo10").sorted(Comparators.NUMBER_AWARE).collect(Collectors.toList())); // Prints [foo1, foo2, foo10]

System.out.println("foo".compareTo("bar")); // Prints 4
System.out.println(Comparators.normalize(String::compareTo).compare("foo", "bar")); // Prints 1

New Bag collection type:

final var bag = new MapBag<String>();
bag.add("foo");
final var quantity = 5L;
bag.add("bar", quantity);
System.out.println(bag.count("foo")); // Prints 1
System.out.println(bag.count("bar")); // Prints 5
System.out.println(bag.distinct()); // Prints 2
System.out.println(bag.size()); // Prints 6

Iterator utility tools:

// Iterator to iterate over elements grouping them
final var batchSize = 3;
final var batchIterator = new BatchIterator<>(
		Iterators.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10),
		batchSize
);

// Iterator that counts iterated groups
final var countIterator = new CountIterator<>(batchIterator);

// Wrap the Iterator so that it could be used in a foreach-style loop for a better readability
for (final var list : Iterables.wrap(countIterator)) {
	System.out.println(list); // Prints [1, 2, 3], [4, 5, 6], [7, 8, 9] and [10]
}

System.out.println(countIterator.getCount()); // Prints 4

Recurrent functions availability

	InputStreams	OutputStreams	Readers	Writers	Strings	*Arrays
EMPTY	✓	✓	✓	✓	✓	✓
nullToEmpty	✓	✓	✓	✓	✓	✓
nullToDefault	✓	✓	✓	✓	✓	✓
emptyToNull					✓	✓
emptyToDefault					✓	✓
isEmpty					✓	✓
buffered	✓	✓	✓	✓
uncloseable	✓	✓	✓	✓
length	✓		✓
concat	✓		✓			✓
join	✓		✓			✓
tee		✓		✓
singleton	✓		✓			✓
of	✓	✓	✓	✓	✓	✓

	Lists	Sets	Maps	Bags	Iterables	Iterators
empty				✓	✓
nullToEmpty	✓	✓	✓	✓	✓	✓
nullToDefault	✓	✓	✓	✓	✓	✓
emptyToNull	✓	✓	✓	✓		✓
emptyToDefault	✓	✓	✓	✓		✓
isEmpty						✓
unmodifiable				✓	✓	✓
length					✓	✓
concat	✓				✓	✓
join	✓				✓	✓
singleton				✓	✓	✓
of				✓	✓	✓
ofOrdered		✓	✓

Specific Maven goals

Generate the Javadoc API documentation:

mvn javadoc:javadoc

Generate the Jacoco test coverage report:

mvn jacoco:report

Update sources license:

mvn license:format

License

This project is licensed under the MIT License.