// limitations under the License.

[[writing_tasks]]
= Writing Tasks

Gradle tasks are created by extending link:{javadocPath}/org/gradle/api/DefaultTask.html[`DefaultTask`].

However, the generic `DefaultTask` provides no action for Gradle.
If users want to extend the capabilities of Gradle and their build script, they must either use a *built-in task* or create a *custom task*:

import org.gradle.api.Plugin
import org.gradle.api.Project
import org.gradle.api.file.FileSystemOperations
import org.gradle.api.provider.ProviderFactory
import org.gradle.api.DefaultTask
import org.gradle.api.tasks.Input
import org.gradle.api.tasks.TaskAction
import org.gradle.workers.WorkAction
import org.gradle.workers.WorkParameters
import org.gradle.workers.WorkerExecutor
import org.gradle.tooling.provider.model.ToolingModelBuilder

            withProblem("Task `:broken` of type `org.gradle.api.DefaultTask`: cannot deserialize object of type 'org.gradle.api.Project' as these are not supported with the configuration cache.")

        myProperty.set("Hello, Gradle!")
        println myProperty.get()
    }
}
// end::object-factory[]

// tag::object-factory-inject[]
abstract class MyObjectFactoryTask extends DefaultTask {
    private ObjectFactory objectFactory

    @Inject //@javax.inject.Inject
    MyObjectFactoryTask(ObjectFactory objectFactory) {
        this.objectFactory = objectFactory
    }

    @TaskAction

// Accessing a provider
println(simpleMessageProvider.get())
// end::set-prov[]

// tag::introduction[]
abstract class MyIntroTask extends DefaultTask {
    @Input
    abstract Property<String> getConfiguration()

    @TaskAction
    void printConfiguration() {
        println "Configuration value: ${configuration.get()}"
    }
}

import org.gradle.api.DefaultTask;
import org.gradle.api.provider.Property;
import org.gradle.api.tasks.Input;
import org.gradle.api.tasks.TaskAction;

import java.net.URI;

// tag::download[]
public abstract class Download extends DefaultTask {
    @Input
    public abstract Property<URI> getUri(); // abstract getter of type Property<T>

    @TaskAction
    void run() {

=====

== Step 3. Create a custom Task

To create a custom task, you must subclass link:{groovyDslPath}/org.gradle.api.DefaultTask.html#org.gradle.api.DefaultTask[`DefaultTask`] in Groovy DSL or link:{kotlinDslPath}/gradle/org.gradle.api/-default-task/index.html[`DefaultTask`] in Kotlin DSL.

package org.myorg;

import org.gradle.api.DefaultTask;
import org.gradle.api.provider.Property;
import org.gradle.api.tasks.Input;
import org.gradle.api.tasks.TaskAction;

// tag::snippet[]
abstract public class LatestArtifactVersion extends DefaultTask {

    @Input
    abstract public Property<String> getCoordinates();

    @Input
    abstract public Property<String> getServerUrl();

    @TaskAction

    }

    def "emits deprecation warning when convention mapping is used with Provider"() {
        buildFile << """
            abstract class MyTask extends DefaultTask {
                @Inject abstract ProviderFactory getProviderFactory()

                @Internal abstract Property<String> getOther()

                @Internal Provider<String> getFoo() {

            import javax.annotation.Nullable;
            import javax.inject.Inject;
            import org.gradle.api.DefaultTask;
            import org.gradle.api.file.FileSystemOperations;
            import org.gradle.api.tasks.TaskAction;

            public abstract class CustomTask extends DefaultTask {
                @Inject
                public abstract FileSystemOperations getFileSystemOperations();