Each message should be on a new line

Question about the task

Resolved

You don't need to look at the main method, it is for testing purposes. The code of the actual method does not pass the final stage of verification, stating that each message should start on a new line. Well, this is what is happening. I just want to know if there is something not right with my code, or if the verification is not rightly written.

Implement the UncaughtExceptionHandler interface in the Solution class, which must:
1. Interrupt the thread that threw the exception.
2. Display the exception's stack trace, starting with the innermost exception.

new Exception("ABC", new RuntimeException("DEF", new IllegalAccessException("GHI"))) Example output: java.lang.IllegalAccessException: GHI java.lang.RuntimeException: DEF java.lang.Exception: ABC

Requirements:

The Solution class must implement the Thread.UncaughtExceptionHandler interface.
After calling uncaughtException(), you must interrupt the thread that threw the exception.
Then display the exception stack trace, starting with the innermost exception.
Messages should be displayed in this format: "<exception class>: <exception message>".

package com.codegym.task.task25.task2512; /* Charting our own course */ import java.io.PrintWriter; import java.io.StringWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.LinkedList; import java.util.List; public class Solution implements Thread.UncaughtExceptionHandler { @Override public void uncaughtException(Thread t, Throwable e) { t.interrupt(); StringWriter sw = new StringWriter(); e.printStackTrace(new PrintWriter(sw)); String exceptionAsString = sw.toString(); //System.out.println(exceptionAsString); String[] array = exceptionAsString.split(" "); List<String> list = Arrays.asList(array); ArrayList<String> classString = new ArrayList<>(); ArrayList<String> messageString = new ArrayList<>(); for (int i = 0; i< list.size(); i++) { if (list.get(i).contains("java.")) { classString.add(list.get(i)); messageString.add(list.get(i+1)); } } for (int i = classString.size()-1; i >= 0; i--) { System.out.println(classString.get(i) + " " + messageString.get(i).split("[^a-zA-Z0-9]\n")[0]); } } public static void main(String[] args) { try { throw new Exception("ABC", new RuntimeException("DEF", new IllegalAccessException("GHI"))); } catch (Exception e) { StringWriter sw = new StringWriter(); e.printStackTrace(new PrintWriter(sw)); String exceptionAsString = sw.toString(); //System.out.println(exceptionAsString); String[] array = exceptionAsString.split(" "); List<String> list = Arrays.asList(array); ArrayList<String> classString = new ArrayList<>(); ArrayList<String> messageString = new ArrayList<>(); for (int i = 0; i< list.size(); i++) { if (list.get(i).contains("java.")) { classString.add(list.get(i)); messageString.add(list.get(i+1)); } } for (int i = classString.size()-1; i >= 0; i--) { System.out.println(classString.get(i) + " " + messageString.get(i).split("[^a-zA-Z0-9]\n")[0]); } List<String> res = new LinkedList<>(); while (e != null) { res.add(0, e.toString()); e = (Exception) e.getCause(); } for (String s : res) { System.out.println(s); } } } }

Comments (1)

Popular
New
Old

You must be signed in to leave a comment

Thomas

Level 41 , Bayreuth, Germany

22 September 2021, 09:02

solution

Your code won't work with exceptions not defined in the java package. Probably CG is using some exception they've written just for validation purposes. So you really need to get it from the passed throwable cause. That's not that difficult. It basically is working like nodes in eg. a linked list. You save the data in an object and a reference to the next object. Here it is the same. An exception contains the data for this exception and a link to the rethrown exception (the inner exception). And all code should reside in the exception handlers method and you're not supposed to catch the exception. That's the purpose of the Uncaught exception handler. It catches not caught exceptions. For that you need to 'set' it for this or all threads like:

// Solution is the UEH... create an instance. We need set to attach that handler to a thread
Solution s = new Solution();
Thread.currentThread().setUncaughtExceptionHandler(s);
// or Thread.setDefaultUncaughtExceptionHandler(s); // attaching this UEH to all threads not having a UEH
throw new Exception("ABC", new RuntimeException("DEF", new IllegalAccessException("GHI")));