Add 'Printing Quotes' solution

Author: durimkryeziu

README.md

@@ -6,7 +6,7 @@ Exercises for Programmers: 57 Challenges to Develop Your Coding Skills by Brian
 **Input, Processing, and Output**
 - Exercise 1. [Saying Hello](https://github.com/durimkryeziu/exercises-for-programmers-java/tree/main/saying-hello)
 - Exercise 2. [Counting the Number of Characters](https://github.com/durimkryeziu/exercises-for-programmers-java/tree/main/characters-count)
-- Exercise 3. Printing Quotes
+- Exercise 3. [Printing Quotes](https://github.com/durimkryeziu/exercises-for-programmers-java/tree/main/printing-quotes)
 - Exercise 4. Mad Lib
 - Exercise 5. Simple Math
 - Exercise 6. Retirement Calculator

printing-quotes/build.gradle

@@ -0,0 +1,16 @@
+plugins {
+    id 'java'
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    testImplementation(libs.assertj.core)
+    testImplementation(libs.junit.jupiter)
+}
+
+tasks.named('test') {
+    useJUnitPlatform()
+}

printing-quotes/src/main/java/com/craftsmanshipinsoftware/prntqts/Main.java

@@ -0,0 +1,9 @@
+package com.craftsmanshipinsoftware.prntqts;
+
+public class Main {
+
+  public static void main(String[] args) {
+    QuotesPrinter quotesPrinter = new QuotesPrinter(System.in, System.out);
+    quotesPrinter.displayQuote();
+  }
+}

printing-quotes/src/main/java/com/craftsmanshipinsoftware/prntqts/QuotesPrinter.java

@@ -0,0 +1,44 @@
+package com.craftsmanshipinsoftware.prntqts;
+
+import java.io.InputStream;
+import java.io.PrintStream;
+import java.util.Objects;
+import java.util.Scanner;
+
+class QuotesPrinter {
+
+  private final InputStream inputStream;
+  private final PrintStream printStream;
+
+  QuotesPrinter(InputStream inputStream, PrintStream printStream) {
+    Objects.requireNonNull(inputStream, "inputStream must not be null");
+    Objects.requireNonNull(printStream, "printStream must not be null");
+    this.inputStream = inputStream;
+    this.printStream = printStream;
+  }
+
+  void displayQuote() {
+    try (Scanner scanner = new Scanner(this.inputStream)) {
+      askForQuote();
+      String quote = scanner.hasNext() ? scanner.nextLine() : null;
+      askForAuthor();
+      String author = scanner.hasNext() ? scanner.nextLine() : null;
+      if (quote == null || quote.isBlank()) {
+        this.printStream.println("Please enter the quote!");
+      } else if (author == null || author.isBlank()) {
+        this.printStream.println("Please enter the author!");
+      } else {
+        this.printStream.printf("%s says, \"%s\"%n", author, quote);
+      }
+    }
+  }
+
+  private void askForQuote() {
+    System.out.print("What is the quote? ");
+  }
+
+  private void askForAuthor() {
+    System.out.print("Who said it? ");
+  }
+
+}

printing-quotes/src/test/java/com/craftsmanshipinsoftware/prntqts/QuotesPrinterTest.java

@@ -0,0 +1,42 @@
+package com.craftsmanshipinsoftware.prntqts;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import org.junit.jupiter.api.Test;
+
+class QuotesPrinterTest {
+
+  @Test
+  void displayQuote_GivenNoQuote_ShouldAskToEnterTheQuote() {
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    QuotesPrinter quotesPrinter = new QuotesPrinter(new ByteArrayInputStream(new byte[0]), new PrintStream(outputStream));
+
+    quotesPrinter.displayQuote();
+
+    assertThat(outputStream).hasToString("Please enter the quote!" + System.lineSeparator());
+  }
+
+  @Test
+  void displayQuote_GivenQuoteWithoutAuthor_ShouldAskToEnterTheAuthor() {
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    QuotesPrinter quotesPrinter = new QuotesPrinter(new ByteArrayInputStream("To be or not to be".getBytes()), new PrintStream(outputStream));
+
+    quotesPrinter.displayQuote();
+
+    assertThat(outputStream).hasToString("Please enter the author!" + System.lineSeparator());
+  }
+
+  @Test
+  void displayQuote_GivenQuoteAndAuthor_ShouldPrintQuoteWithAuthor() {
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    QuotesPrinter quotesPrinter = new QuotesPrinter(new ByteArrayInputStream("To be or not to be\nWilliam Shakespeare".getBytes()),
+        new PrintStream(outputStream));
+
+    quotesPrinter.displayQuote();
+
+    assertThat(outputStream).hasToString("William Shakespeare says, \"To be or not to be\"" + System.lineSeparator());
+  }
+}

settings.gradle

@@ -1,2 +1,2 @@
 rootProject.name = 'exercises-for-programmers-java'
-include('saying-hello', 'characters-count')
+include('saying-hello', 'characters-count', 'printing-quotes')