bluelhf / Tasks

A simple task system for Java.

Tasks

Tasks is a simple and versatile asynchronous task handler.

It can be used to create complex task systems, and supports custom executor services and progress objects.

Creating Tasks

Creating a task with Tasks is easy:

int max = 100000;
Task<Integer, String> task = Task.of((Task<Integer, String>.Delegate delegate) -> {
    for (int i = 0; i <= max; i++) {
        delegate.setProgress(i);
        LockSupport.parkNanos((long) 1E+8); // 100ms
    }
    return "Hello, world!";
});

task.run(); // or task.runAsync() or task.runAsync(Executor)

This snippet creates a new Task object that returns Integer progress objects and resolves to a String object. When we run the task, we can access the Integer value it's on because it calls delegate.setProgress(i) in its for-loop. When it completes, its getResult method will return "Hello, world!"

Tasks also have several methods for easily tracking progress and results:

• whileRunning(Consumer<P> progressConsumer, Duration period) causes the progress consumer to be run every period, with the latest progress as input.
• onProgress(BiConsumer<P, P> progressConsumer) works similarly to whileRunning, except runs every time setProgress is called from inside the task, with the old progress and new progress as input respectively.
• onResult(Consumer<R> resultConsumer) is run once when the task completes, with the result as input.

Two of these methods are shown here:

Task.of((Task<Integer, String>.Delegate taskDelegate) -> {
    for (int i = 0; i <= max; i++) {
        taskDelegate.setProgress(i);
        LockSupport.parkNanos((long) 1E+8);
    }
    return "Hello, world!";
})
    .whileRunning((progress) -> System.out.print("\r" + getProgressBar(progress, max)), Duration.ofMillis(1000))
    .onResult((result) -> System.out.println("\n" + result))
    .runAsync().join(); // equivalent to run();

Using Tasks in your Maven project

Tasks is deployed directly to GitHub! This makes it nice and easy to use it, without having to use messy software like JitPack or publish to an actual repository!

Simply add this to your pom.xml:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <version>3.2.4</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <createDependencyReducedPom>false</createDependencyReducedPom>
                    </configuration>
                </execution>
            </executions>
            <configuration>
                <relocations>
                    <relocation>
                        <pattern>io.github.bluelhf.tasks</pattern>
                        <shadedPattern>YOUR.PACKAGE.HERE.tasks</shadedPattern>
                    </relocation>
                </relocations>
            </configuration>
        </plugin>
    </plugins>
</build>

<repositories>
    <repository>
        <id>tasks-repo</id>
        <url>https://raw.githubusercontent.com/bluelhf/Tasks/mvn-repo/</url>
    </repository>
</repositories>

<dependencies>
    <dependency>
        <groupId>io.github.bluelhf</groupId>
        <artifactId>Tasks</artifactId>
        <version>0000</version>
    </dependency>
</dependencies>

(Make sure to replace YOUR.PACKAGE.HERE with your qualified artifact ID!)