Java: what are IOEXceptions in BufferedReader's readLine() for?

Question

I can \"fix\" the below exception with a try-catch loop but I cannot understand the reason.

1. Why does the part \"in.readLine()\" continuosly ignite IOExceptions? <

Answer 1

BufferedReader.readLine() is declared as potentially throwing an exception, see: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/BufferedReader.html#readLine()

You either need to catch it, or declare your main method as throwing IOException.

Ie, either do this:

try {
    while((s=in.readLine()) != null){
        System.out.println(s);
     }
} catch(IOException e) {
    // Code to handle the exception.
}

Or

public static void main(String[] args) throws IOException { ...