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Question about the task

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Can somebody give a little hint?

1. Analyze the exceptions thrown by the BEAN.throwExceptions method.
2. The handleExceptions method must call the BEAN.throwExceptions method and handle exceptions:
2.1. if there is a FileSystemException, then log it (call the BEAN.log method) and rethrow
2.2. if there is a CharConversionException or any other IOException, then just log it (call the BEAN.log method)
3. Add to the handleExceptions method signature the exception class you throw in Item 2.1.
4. In the main method, handle the remaining exception by logging it. Use try-catch

Hint:
If you capture a MyException and you didn't want to catch it, you can rethrow it using code like:
catch (MyException e) { throw e; }

Requirements:

The handleExceptions method must call the BEAN.throwExceptions method.
The handleExceptions method should log the FileSystemException (call the BEAN.log method), and then rethrow it.
The handleExceptions method should only log (call the BEAN.log method) the CharConversionException.
The handleExceptions method should only log any IOException.
Add the FileSystemException class to the signature of the handleExceptions method.
The main method should use try-catch.
The main method should log the exceptions thrown by the handleExceptions method.

package com.codegym.task.task09.task0915; import java.io.CharConversionException; import java.io.IOException; import java.nio.file.FileSystemException; /* Catching custom exceptions */ public class Solution { public static StatelessBean BEAN = new StatelessBean(); public static void main(String[] args) { try{ handleExceptions(); } catch(Exception e){ } } public static void handleExceptions(){ try{ BEAN.throwExceptions();} catch(CharConversionException e){ BEAN.log(e); throw e; } catch(FileSystemException e){ BEAN.log(e); throw e; } catch(IOException e){ BEAN.log(e); throw e; } } public static class StatelessBean { public void log(Exception exception) { System.out.println(exception.getMessage() + ", " + exception.getClass().getSimpleName()); } public void throwExceptions() throws CharConversionException, FileSystemException, IOException { int i = (int) (Math.random() * 3); if (i == 0) throw new CharConversionException(); if (i == 1) throw new FileSystemException(""); if (i == 2) throw new IOException(); } } }

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Gellert Varga

Level 23 , Szekesfehervar, Hungary

21 April 2021, 23:02

I tried run your program and the JVM says this messages: "must be caught or declared to be thrown: >>throw e<<" But our purpose is to rethrow it, so the "must be caught" part of the JVM's suggestion is not applicable here, only the "declared to be thrown". (You can do it in the method declaration.) - - - - - - - - - - - I think you need to understand: if an Exception occured anywhere, the JVM interrupt the normal working immediately, and from now on it focus only on to get rid of this Exception in some wise. way 1.: if there is a catch block after that place where the Exception is occured then the catch block terminates the Exception. way 2: If there is no catch block that can catch the current exception, the method must throw this Exception to the caller. So the JVM passes the exception to the caller who called our method where the exception occurred. For this purpose we need declare our method this way: method23() throws Exception This way the Exception will be moved to the upper method. The JVM is also looking for the right catch block there. If there is not, this method should also throw the exception, trusting that it will finally be caught somewhere... If nowhere, the program will end and the Exception message will be printed.

jai singh

Level 11 , ludhiana, India

20 April 2021, 20:08

you dont have to throw CharConversionException and IOException in your handleExceptions() method. Also another hint is to read about throwing exceptions a little more as you are missing one more thing in your code (more hint : its in method declaration of handleExceptions() ).