使用其他方法处理其他方法中的异常catch

Question

我需要将结果看作boolean result：true。但是我需要以非常规方式来做到这一点。

import java.io.IOException; 

public class FlashLight { 

    private Bulb bulb; 
    private Battery[] batteries; 

    public void on() { 
     try { 

      if (this.IsThereEnoughPower()) { 

       this.bulb.setOn(true); 

       for (Battery b : batteries) { 
        b.setPower(b.getPower() - this.bulb.getBrightness()); 
       } 
      } 

     } catch (IOException e) { 
      System.out.println(e.getMessage()); 

      this.setBatteries(new Battery[4]); 

     } 
    } 

我需要赶上方法on()例外，但我只能修改方法：DetermineIfFlashlightCanBeTurnedOn

public boolean DetermineIfFlashlightCanBeTurnedOn() throws IOException { 

     return bulb != null && DetermineIfBatteriesAreInstalled() && IsThereEnoughPower(); 
    } 

    private boolean DetermineIfBatteriesAreInstalled() throws IOException { 
     if (batteries.length < 4) { 
      throw new IOException(Math.abs(-4 + batteries.length)); 
     } 
     for (Battery b : batteries) { 
      if (b == null) { 
       return false; 
      } 
     } 

     return true; 
    } 

    private boolean IsThereEnoughPower() { 
     for (Battery b : batteries) { 
      if (b.getPower() < MIN_BATTERY_POWER) { 
       return false; 
      } 
     } 

     return true; 
    } 

    private static void testLatarki(String... args) { 

     FlashLight flashlight = new Flashlight(); 
     System.out.println(flashlight.DetermineIfFlashlightCanBeTurnedOn()); 
    } 
} 

例外只能在被捕获（）方法。 DetermineIfBatteriesAreInstalled（）确定IfFlashlightCanBeTurnedOn 必须标记为：throws IOException。

Answer 1

您可以使用try{}catch(){}代替：

public boolean DetermineIfFlashlightCanBeTurnedOn() { 
    try { 
     return bulb != null && DetermineIfBatteriesAreInstalled() && IsThereEnoughPower(); 
    } catch (Exception e) { 
     //log your exception 
    } 
    return false; 
} 

---

我忘了只在告诉你们，我可以使用try/catch块（） 方法

---

在这种情况下，您可以使用RuntimeException你不需要使用throws IOException在你的方法：

if (batteries.length < 4) { 
    throw new RuntimeException(Math.abs(-4 + batteries.length)+""); 
} 

所以：

public boolean DetermineIfFlashlightCanBeTurnedOn() { 
//--not need to use throw throws IOException-------^ 
    return bulb != null && DetermineIfBatteriesAreInstalled() && IsThereEnoughPower(); 
} 

private boolean DetermineIfBatteriesAreInstalled() { 
//--not need to use throw throws IOException------^ 
    if (batteries.length < 4) { 
     throw new RuntimeException(Math.abs(-4 + batteries.length) + ""); 
     //----------^^ 
    } 
    for (Battery b : batteries) { 
     if (b == null) { 
      return false; 
     } 
    } 

    return true; 
} 

---

你可以在这里阅读更多Is there a way to throw an exception without adding the throws declaration?