how to throw an IOException?

Question

public class ThrowException {
    public static void main(String[] args) {
        try {
            foo();
        }
        catch(Exception e) {
             if (e         


        

Answer 1

If the goal is to throw the exception from the foo() method, you need to declare it as follows:

public void foo() throws IOException{
    //do stuff
    throw new IOException("message");
}

Then in your main:

public static void main(String[] args){
    try{
        foo();
    } catch (IOException e){
        System.out.println("Completed!");
    }
}

Note that, unless foo is declared to throw an IOException, attempting to catch one will result in a compiler error. Coding it using a catch (Exception e) and an instanceof will prevent the compiler error, but is unnecessary.