feat: adds Lesson 14 content and homework assignment (code-differentl…

…y#330)

* chore: adds lesson_14 boilerplate.

* chore: adds initial sqlite db for library data.

* feat: implements db data loader

* chore: adds @service annotation to core loaders.

* docs: adds homework instructions

* chore: add lesson 14 build actions

* docs: fix misspelling

* docs: updating for clarity.

* chore: nit updates

.devcontainer/devcontainer.json

@@ -14,7 +14,8 @@
  "ghcr.io/devcontainers/features/node:1": {},
  "ghcr.io/devcontainers/features/python:1": {},
  "ghcr.io/devcontainers-contrib/features/ts-node:1": {},
- "ghcr.io/devcontainers/features/sshd:1": {}
+ "ghcr.io/devcontainers/features/sshd:1": {},
+ "ghcr.io/warrenbuckley/codespace-features/sqlite:1": {}
  },
  "portsAttributes": {
  "80": {
@@ -32,7 +33,8 @@
  "ms-vscode.vscode-typescript-next",
  "ms-dotnettools.csdevkit",
  "ritwickdey.LiveServer",
- "mechatroner.rainbow-csv"
+ "mechatroner.rainbow-csv",
+ "alexcvzz.vscode-sqlite"
  ]
  }
  }

.github/workflows/check_lesson_14_pr.yml

@@ -0,0 +1,33 @@
+name: Check Lesson 14 Pull Request
+
+on:
+ pull_request:
+ branches: [ "main" ]
+ paths:
+ - "lesson_14/db/**"
+
+jobs:
+ build:
+
+ runs-on: ubuntu-latest
+ permissions:
+ contents: read
+
+ steps:
+ - uses: actions/checkout@v4
+ - name: Set up JDK 17
+ uses: actions/setup-java@v4
+ with:
+ java-version: '17'
+ distribution: 'temurin'
+
+ # Configure Gradle for optimal use in GiHub Actions, including caching of downloaded dependencies.
+ # See: https://github.com/gradle/actions/blob/main/setup-gradle/README.md
+ - name: Setup Gradle
+ uses: gradle/actions/setup-gradle@417ae3ccd767c252f5661f1ace9f835f9654f2b5 # v3.1.0
+
+ - name: Build Lesson 14 with Gradle Wrapper
+ working-directory: ./lesson_14/db
+ run: ./gradlew check
+
+

.github/workflows/check_push.yml

@@ -16,6 +16,10 @@ on:
  - "lesson_10/examples/**"
  - "lesson_10/quiz/**"
  - "lesson_10/solid/**"
+ - "lesson_12/io/**"
+ - "lesson_13/bank/**"
+ - "lesson_14/algos/**"
+ - "lesson_14/db/**"
 
 jobs:
  build:
@@ -85,6 +89,18 @@ jobs:
  working-directory: ./lesson_12/io
  run: ./gradlew assemble && ./gradlew spotlessCheck
 
+ - name: Build Lesson 13 with Gradle Wrapper
+ working-directory: ./lesson_13/bank
+ run: ./gradlew check
+
+ - name: Build Lesson 14 Algos with Gradle Wrapper
+ working-directory: ./lesson_14/algos
+ run: ./gradlew check
+
+ - name: Build Lesson 14 DB with Gradle Wrapper
+ working-directory: ./lesson_14/db
+ run: ./gradlew check
+
  - name: Build Shared Lib with Gradle Wrapper
  working-directory: ./lib/java/codedifferently-instructional
  run: ./gradlew check

.gitignore

@@ -140,3 +140,11 @@ dist
 .pnp.*
 
 .DS_Store
+
+# Python
+*.pyc
+*.pyo
+*.pyd
+__pycache__/
+venv/
+pip-log.txt

lesson_14/README.md

@@ -0,0 +1,28 @@
+# Lesson 14
+
+## Homework
+
+* Memorize the `printPermutations` and `reverseString` methods in [algos_app][algos-app].
+* [Extra credit] Complete [Loading the Library, Part II](#loading-the-library-part-ii) assignment.
+
+## Loading The Library, Part II
+
+Instead of loading our library data from JSON or CSV files, we now want to load data from a proper database. A new implementation of the `LibraryDbDataLoader` data loader has been provided to accomplish this task and is now the [default data loader][library-app] for the app.
+
+To build familiarity in working with databases, you are charged with the following tasks:
+
+* Write a `.sql` script file that queries the following data. Use a unique name for your file and store it in the [queries][queries-dir] directory of the resources folder.
+ * A `SELECT` query that returns the counts of media items by type.
+ * A `SELECT` query that returns the sum of total pages checked out by guests.
+ * A `SELECT` query that shows all 5 guests and any corresponding records in the `checked_out_items` table.
+* Add a new table called `library_users` to the SQLite database that stores a user's id (UUID formatted string), email, first name, last name, and a password (bcrypt encoded string). Add a model and repository that loads the users into the LibraryDataModel. Populate the database with a few users.
+
+As before, you can run the app from the console using the following command:
+
+```bash
+./gradlew run --console=plain
+```
+
+[algos-app]: ./algos/algos_app/src/main/java/com/codedifferently/lesson14/Lesson14.java
+[queries-dir]: ./db/db_app/src/main/resources/queries/
+[library-app]: ./db/db_app/src/main/java/com/codedifferently/lesson14/cli/LibraryApp.java#L26

lesson_14/algos/.gitattributes

@@ -0,0 +1,9 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat text eol=crlf
+

lesson_14/algos/.gitignore

@@ -0,0 +1,5 @@
+# Ignore Gradle project-specific cache directory
+.gradle
+
+# Ignore Gradle build output directory
+build

lesson_14/algos/algos_app/build.gradle.kts

@@ -0,0 +1,64 @@
+plugins {
+ // Apply the application plugin to add support for building a CLI application in Java.
+ application
+ eclipse
+ id("com.diffplug.spotless") version "6.25.0"
+ id("org.springframework.boot") version "3.2.2"
+ id("com.adarshr.test-logger") version "4.0.0"
+}
+
+apply(plugin = "io.spring.dependency-management")
+
+repositories {
+ // Use Maven Central for resolving dependencies.
+ mavenCentral()
+}
+
+dependencies {
+ // Use JUnit Jupiter for testing.
+ testImplementation("com.codedifferently.instructional:instructional-lib")
+ testImplementation("org.junit.jupiter:junit-jupiter:5.9.1")
+ testImplementation("org.springframework.boot:spring-boot-starter-test")
+ testImplementation("org.assertj:assertj-core:3.25.1")
+ testImplementation("at.favre.lib:bcrypt:0.10.2")
+
+ // This dependency is used by the application.
+ implementation("com.codedifferently.instructional:instructional-lib")
+ implementation("com.google.guava:guava:31.1-jre")
+ implementation("com.google.code.gson:gson:2.10.1")
+ implementation("org.projectlombok:lombok:1.18.30")
+ implementation("org.springframework.boot:spring-boot-starter")
+}
+
+application {
+ // Define the main class for the application.
+ mainClass.set("com.codedifferently.lesson14.Lesson14")
+}
+
+tasks.named<Test>("test") {
+ // Use JUnit Platform for unit tests.
+ useJUnitPlatform()
+}
+
+
+configure<com.diffplug.gradle.spotless.SpotlessExtension> {
+
+ format("misc", {
+ // define the files to apply `misc` to
+ target("*.gradle", ".gitattributes", ".gitignore")
+
+ // define the steps to apply to those files
+ trimTrailingWhitespace()
+ indentWithTabs() // or spaces. Takes an integer argument if you don't like 4
+ endWithNewline()
+ })
+
+ java {
+ // don't need to set target, it is inferred from java
+
+ // apply a specific flavor of google-java-format
+ googleJavaFormat()
+ // fix formatting of type annotations
+ formatAnnotations()
+ }
+}

lesson_14/algos/algos_app/src/main/java/com/codedifferently/lesson14/Lesson14.java

@@ -0,0 +1,69 @@
+package com.codedifferently.lesson14;
+
+public class Lesson14 {
+
+ public static void main(String[] args) {
+ System.out.println("The permutations of 'abc' are:");
+ printPermutations("abc", "");
+
+ System.out.println();
+ System.out.print("The reverse of 'abcd' is: ");
+ System.out.println(reverseString("abc"));
+ }
+
+ /**
+ * Prints all the permutations of a string.
+ *
+ * @param value The string to permute.
+ * @param answer The current permutation.
+ */
+ public static void printPermutations(String value, String answer) {
+ if (value.length() == 0) {
+ System.out.println(answer);
+ return;
+ }
+
+ for (int i = 0; i < value.length(); i++) {
+ char ch = value.charAt(i);
+ String left = value.substring(0, i);
+ String right = value.substring(i + 1);
+ String rest = left + right;
+ printPermutations(rest, answer + ch);
+ }
+ }
+
+ /**
+ * Reverses a string by swapping the front half of the characters with the back half.
+ *
+ * @param input The string to reverse.
+ * @return The reversed string.
+ */
+ public static String reverseString(String input) {
+ if (input.length() == 0) {
+ return input;
+ }
+
+ char[] charArray = input.toCharArray();
+
+ for (int i = 0; i < charArray.length / 2; i++) {
+ // Compute the corresponding index from the back of the string.
+ var j = charArray.length - i - 1;
+ swapCharacters(charArray, i, j);
+ }
+
+ return new String(charArray);
+ }
+
+ /**
+ * Swaps the characters in the provided character array.
+ *
+ * @param charArray
+ * @param i
+ * @param j
+ */
+ private static void swapCharacters(char[] charArray, int i, int j) {
+ Character temp = charArray[i];
+ charArray[i] = charArray[j];
+ charArray[j] = temp;
+ }
+}

lesson_14/algos/algos_app/src/test/java/com/codedifferently/lesson14/Lesson14Test.java

@@ -0,0 +1,13 @@
+package com.codedifferently.lesson14;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class Lesson14Test {
+
+ @Test
+ void testCanInstantiate() {
+ assertThat(new Lesson14()).isNotNull();
+ }
+}

lesson_14/algos/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.0.2-bin.zip
+networkTimeout=10000
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists