Error Message "Unreported Exception Java.Io.Ioexception; Must Be Caught or Declared to Be Thrown"

Java - Can't handle IOException; must be declared caught or to be thrown

When you add throws Exception to the method signature, that requires that the exception is handled 'upstream' at the point where the method is called.

Something like this:

    try{
     AnimalStats();

}catch(IOException ex){
     // DO SOMETHING
    }

However, If you leave the signature silent on this point, you can handle the exception within the method with your try/catch blocks, as you have done. But for that, you need to remove throws from method signature. Like this:

public AnimalStats(){
    simulator = new Simulator();
    try{
        fos = new FileOutputStream("AnimalStats.csv",true);
        pw = new PrintWriter(fos);
    }
    catch(IOException e) {
        System.out.println("Error has been caught!");
        e.printStackTrace();

    }
}

You can use either of the approach.

ERROR: unreported exception java.io.IOException; must be caught or declared to be thrown

You have to use throws IOException like this :

public static void main(String[] args) throws FileNotFoundException, IOException 

Or you can surround your statement with try{}catch(...){} :

try {
    //Your code ...
} catch (IOException ex) {
    //exception 
}

Unreported exception IOException, must be caught or declared to be thrown

public double findSyl()throws IOException

findSyl() declares that it throws an IOException, which is a checked exception. This means that the caller of findSyl() must either catch that exception or declare that it may throw that exception too.

Your two options :

1.

  public static void main(String[] args)
  {
     findStuff calc = new findStuff();
     try {
         calc.findSyl();
         calc.printRes();
     }
     catch (IOException ex) {
         // handle the exception here
     }  
  }

2.

  public static void main(String[] args) throws IOException
  {
     findStuff calc = new findStuff();   
     calc.findSyl();
     calc.printRes();   
  }

IOException, must be caught or declared to be thrown

The close methods can throw an exception. So they need to catch them.

} finally {
    try {
        br.close();
        isr.close();
        is.close();
    } catch(IOException e) {
        e.printStackTrace();
    }
}

You also have one other issue in your code that will cause it to fail at run time. You are trying to use the AssetManager to open a file on your windows computer and not the phone. Move the file into your your projects' assets folder and then change

is = manager.open("C:\\Users\\serhat\\Copy\\satranc\\Akdag_Reportaj\\dan_akdag.pgn");

to

is = manager.open("dan_akdag.pgn");

Error unreported exception java.io.ioexception must be caught or declared to be thrown in Java class

Your Scanner constructor can throw an IOException, because it's calling setChar(), and that can throw it.

You must either declare your constructor as throwing the exception, or catch the exception in your constructor and deal with it.

unreported exception java.io.ioexception must be caught or declared to be thrown

You really don't have any handling code to offer for your checked exception. It will be perfectly acceptable if that exception just propagates to the caller, in this case the place where new Relay1() is written. To achieve this, write as follows:

final PiFace piface; { 
  try {
    piface = new PiFaceDevice(PiFace.DEFAULT_ADDRESS, Spi.CHANNEL_0);
  } catch(IOException e) { 
    throw new RuntimeException("Failed to create Pi Face Device", e); 
  }
}

This will allow you to both preserve the diagnostic information in the exception, and to satisfy the compiler's wish.

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