Propriedades e configuração de tarefas
Aprenda a adicionar propriedades a tarefas personalizadas, configurá-las e garantir compilações incrementais.
Propriedades e configuração de tarefas é uma aula grátis de Groovy & Gradle: JVM Automation and Build Engineering no CoddyKit. Esta é a aula 3 de 4. Você pode ler a aula completa abaixo gratuitamente — depois pratica ao vivo no navegador com um editor de código integrado e um tutor de IA 24/7. Faz parte do caminho de aprendizado de Groovy & Gradle: JVM Automation and Build Engineering, e seu progresso é sincronizado entre a web e o app CoddyKit. O curso de Groovy & Gradle: JVM Automation and Build Engineering inclui 4 aulas no total.
Partes desta aula ainda não foram traduzidas e aparecem em inglês.
What are Task Properties?
Custom Gradle tasks can be made highly flexible by adding properties. These properties act like variables that allow you to configure a task's behavior from your build.gradle script.
Using properties makes your custom tasks reusable and adaptable to different project needs without having to change their core logic.
Defining Simple Properties
To add a property to a custom task, you simply declare a public field within your task class. For basic types like String, int, or boolean, this is straightforward.
For more advanced scenarios, Gradle also offers dedicated Property types, but we'll start with simple declarations.
Custom Task with a Property
Here's a basic custom task defined directly in build.gradle. It has a message property that will be printed when the task runs. Notice the default value set for the property.
import org.gradle.api.DefaultTask
import org.gradle.api.tasks.TaskAction
class MyMessageTask extends DefaultTask {
String message = "Default task message"
@TaskAction
void printMessage() {
println "Task says: ${message}"
}
}
task helloWorld(type: MyMessageTask)
Configuring Task Properties
Once a task property is defined, you can easily set its value from your build.gradle file. This is done within the task's configuration block, which allows you to customize the task instance.
Run the example to see how the default message is overridden.
import org.gradle.api.DefaultTask
import org.gradle.api.tasks.TaskAction
class MyMessageTask extends DefaultTask {
String message = "Default task message"
@TaskAction
void printMessage() {
println "Task says: ${message}"
}
}
task helloWorld(type: MyMessageTask) {
message = "Hello from CoddyKit!"
}
Inputs for Incremental Builds
One of Gradle's most powerful features is incremental builds. This means Gradle can skip tasks if their inputs and outputs haven't changed since the last build, saving a lot of time.
To enable this, you must tell Gradle which properties are considered task inputs. These are properties whose values influence the task's outcome.
Declaring Input Properties
You mark a property as an input using the @Input annotation. Gradle will then track its value. If the value changes between builds, the task will execute. If not, Gradle can mark it as UP-TO-DATE and skip it.
For file or directory inputs, use @InputFile, @InputDirectory, or @InputFiles.
import org.gradle.api.DefaultTask
import org.gradle.api.tasks.Input
import org.gradle.api.tasks.TaskAction
class MyInputTask extends DefaultTask {
@Input
String greeting = "Hola!"
@TaskAction
void greet() {
println "Greeting: ${greeting}"
}
}
task sayHello(type: MyInputTask) {
greeting = "Bonjour!"
}
Outputs for Incremental Builds
Equally important are outputs. These are the files or directories that your task creates or modifies during its execution. Gradle also tracks these to determine if a task is up-to-date.
If a task's inputs haven't changed AND its declared outputs are present and valid, Gradle knows the task doesn't need to run again.
Declaring Output Properties
You use annotations like @OutputFile for a single result file or @OutputDirectory for a directory containing results. These tell Gradle where the task's generated artifacts will be stored.
The task will ensure the parent directory exists before writing the file.
import org.gradle.api.DefaultTask
import org.gradle.api.tasks.Input
import org.gradle.api.tasks.OutputFile
import org.gradle.api.tasks.TaskAction
class MyOutputFileTask extends DefaultTask {
@Input
String content = "Default report content."
@OutputFile
File outputFile = project.file("build/reports/output.txt")
@TaskAction
void generateFile() {
outputFile.parentFile.mkdirs()
outputFile.write(content)
println "Generated: ${outputFile.name}"
}
}
task generateReport(type: MyOutputFileTask) {
content = "Report data for: " + new Date().format("yyyy-MM-dd HH:mm:ss")
}
The Power of Incremental Builds
By correctly declaring both inputs and outputs, you unlock Gradle's powerful incremental build feature. This means your tasks only run when necessary, drastically speeding up build times.
This optimization is crucial for efficient development workflows and robust CI/CD pipelines, ensuring quick feedback and resource savings.
Quick Check on Properties
Imagine you have a custom Gradle task that takes a specific configuration file as an input. Which annotation would you use for the property that defines the path to this single configuration file?
Recap: Task Properties & Incremental Builds
In this lesson, you learned how to add properties to custom tasks, making them configurable and reusable. You also discovered how to mark properties as inputs (e.g., @Input, @InputFile) and outputs (e.g., @OutputFile, @OutputDirectory).
These annotations are key to enabling Gradle's powerful incremental build feature, which significantly speeds up your builds by skipping tasks that are already up-to-date. Keep practicing to master efficient task configuration!
Perguntas Frequentes
A aula “Propriedades e configuração de tarefas” é grátis?
Sim — o texto completo de “Propriedades e configuração de tarefas” é grátis para ler aqui na web. Para praticá-la interativamente (um editor de código integrado e um tutor de IA 24/7) e desbloquear o restante do curso de Groovy & Gradle: JVM Automation and Build Engineering, atualize para CoddyKit PRO. O curso de Groovy & Gradle: JVM Automation and Build Engineering inclui 4 aulas no total.
O que vou aprender em “Propriedades e configuração de tarefas”?
Aprenda a adicionar propriedades a tarefas personalizadas, configurá-las e garantir compilações incrementais. Você pratica Groovy & Gradle: JVM Automation and Build Engineering com código prático que executa diretamente no navegador, e um tutor de IA 24/7 responde suas dúvidas enquanto trabalha na aula.
Preciso ter experiência prévia para começar Groovy & Gradle: JVM Automation and Build Engineering?
Nenhuma experiência prévia é necessária. Groovy & Gradle: JVM Automation and Build Engineering no CoddyKit é estruturado para alunos iniciantes até avançados, então você pode começar aqui ou desde o início e aprender no seu ritmo. Esta é a aula 3 de 4.
Quanto tempo leva a aula “Propriedades e configuração de tarefas”?
A maioria das aulas CoddyKit leva cerca de 5–10 minutos. Cada uma é compacta e interativa, então você faz progresso constante e retoma exatamente de onde parou entre web e app.
Posso escrever e executar código nesta aula de Groovy & Gradle: JVM Automation and Build Engineering?
Sim. Cada aula de Groovy & Gradle: JVM Automation and Build Engineering inclui um editor de código integrado, então você escreve e executa código real direto no navegador e recebe feedback de IA instantaneamente — nenhuma configuração local necessária.
Todas as aulas deste curso
- Definindo tarefas personalizadas
- Tipos e ações de tarefas
- Propriedades e configuração de tarefas
- Tarefas Incrementais e Verificações de Atualização