معالجة الأخطاء في Futures

معالجة حالات فشل Future

نتيجة Future: Try

استخدام onComplete لمعالجة الأخطاء

import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global
import scala.util.{Success, Failure}

object Main {
  def main(args: Array[String]): Unit = {
    val failingFuture = Future { 
      if (true) throw new RuntimeException("Oops!")
      10
    }

    failingFuture.onComplete {
      case Success(value) => println(s"Success: $value")
      case Failure(exception) => println(s"Failure: ${exception.getMessage}")
    }

    Thread.sleep(100) // Keep JVM alive for Future to complete
  }
}

الدالة recover

مثال على recover

import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global

object Main {
  def main(args: Array[String]): Unit = {
    val resultFuture = Future { 10 / 0 } // This will fail

    val recoveredFuture = resultFuture.recover {
      case e: ArithmeticException =>
        println("Caught ArithmeticException, recovering...")
        0 // Fallback value
    }

    recoveredFuture.foreach(value => println(s"Result: $value"))

    Thread.sleep(100) // Keep JVM alive
  }
}

الدالة recoverWith

مثال على recoverWith

import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global

object Main {
  def main(args: Array[String]): Unit = {
    val primaryOperation = Future { 
      if (true) throw new Exception("Primary failed!")
      100
    }

    val fallbackOperation = Future { 
      println("Running fallback operation...")
      50 
    }

    val finalFuture = primaryOperation.recoverWith {
      case e: Exception =>
        println(s"Primary failed: ${e.getMessage}. Using fallback.")
        fallbackOperation
    }

    finalFuture.foreach(value => println(s"Final result: $value"))

    Thread.sleep(200) // Keep JVM alive
  }
}

الدالة fallbackTo

مثال على fallbackTo

import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global

object Main {
  def main(args: Array[String]): Unit = {
    val failingFuture = Future { 
      if (true) throw new RuntimeException("Network error!")
      "Data from primary"
    }

    val backupFuture = Future { 
      println("Using backup source...")
      "Data from cache"
    }

    val finalResult = failingFuture.fallbackTo(backupFuture)

    finalResult.foreach(value => println(s"Retrieved: $value"))

    Thread.sleep(100) // Keep JVM alive
  }
}

اختبار معالجة الأخطاء

مراجعة: معالجة أخطاء Future