try/catch/finally

مقدمة

نظرة عامة على try/catch

الشفرة: try/catch البسيطة

public class Main {
  public static void main(String[] args) {
    try {
      int x = 10 / 0; // risky division
      System.out.println("Result=" + x);
    } catch (ArithmeticException e) {
      System.out.println("Cannot divide by zero!");
    }
  }
}

كتل catch متعددة

الشفرة: كتل catch متعددة

public class Main {
  public static void main(String[] args) {
    try {
      String s = null;
      System.out.println(s.length()); // NullPointerException
    } catch (ArithmeticException e) {
      System.out.println("Math error");
    } catch (NullPointerException e) {
      System.out.println("Null reference error");
    }
  }
}

الشفرة: كتلة finally

public class Main {
  public static void main(String[] args) {
    try {
      int[] arr = {1,2};
      System.out.println(arr[5]); // ArrayIndexOutOfBounds
    } catch (ArrayIndexOutOfBoundsException e) {
      System.out.println("Bad index!");
    } finally {
      System.out.println("Finally block always runs");
    }
  }
}

التحقق من finally

خلاصة