package com.example;

import static org.junit.jupiter.api.Assertions.assertTrue;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;

import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

public class MainTest {

    @Test
    @DisplayName("simulateNetworkRequestRetry() prints correct retry messages and failure message")
    void testSimulateNetworkRequestRetryOutput() {
        int maxAttempts = 5;
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        PrintStream originalOut = System.out;
        System.setOut(new PrintStream(outContent));

        Main.simulateNetworkRequestRetry(maxAttempts);

        System.setOut(originalOut);

        String output = outContent.toString().trim();
        String[] lines = output.split("\\r?\\n");

        assertTrue(lines.length == maxAttempts + 1,
                "Expected " + (maxAttempts + 1) + " lines, but got " + lines.length);

        for (int i = 1; i <= maxAttempts; i++) {
            assertTrue(lines[i - 1].trim().equals("Attempt " + i + ": Connecting to server..."),
                    "Incorrect message for attempt " + i);
        }

        assertTrue(lines[maxAttempts].trim().equals("All attempts failed. Please try again later."),
                "Missing or incorrect failure message");
    }
}

MainTest.java

A beginner-friendly course designed to introduce learners to the fundamentals of loops in Java. Through a blend of clear explanations, practical examples, and hands-on tasks, students will gain confidence in using for, while, and do-while loops, as well as applying them to solve real-world problems.

Introduce the concept of loops, their necessity, and the basic structure of for, while, and do-while loops in Java. This section lays the foundation for understanding how repetition works in programming.

Dive deeper into different loop types, including do-while loops and nested loops, and learn how to control loop execution with break and continue.

Apply loop concepts to solve practical problems, including working with arrays and combining loops with conditionals.

Challenge: Simulating Network Retries

解答