Add JDB JSON storage and CI workflow

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+
+      - name: Cache Gradle packages
+        uses: actions/cache@v3
+        with:
+          path: ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x ./gradlew
+
+      - name: Build with Gradle
+        run: ./gradlew build
+
+      - name: Run tests
+        run: ./gradlew test

build.gradle.kts

@@ -25,6 +25,11 @@ dependencies {
     // database drivers
     compileOnly("org.xerial:sqlite-jdbc:3.46.0.0")
     compileOnly("mysql:mysql-connector-java:8.0.33")
+
+    // testing
+    testImplementation("org.junit.jupiter:junit-jupiter-api:5.10.3")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.11.1")
+    testImplementation("com.google.code.gson:gson:2.11.0")
 }
 
 tasks {
@@ -79,4 +84,8 @@ tasks {
     processResources {
         filteringCharset = Charsets.UTF_8.name() // We want UTF-8 for everything
     }
+
+    test {
+        useJUnitPlatform()
+    }
 }

src/main/java/de/oliver/fancylib/jdb/JDB.java

@@ -0,0 +1,117 @@
+package de.oliver.fancylib.jdb;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * The JDB class provides a simple JSON document-based storage system in a specified directory.
+ */
+public class JDB {
+
+    private final static Gson GSON = new GsonBuilder()
+            .serializeNulls()
+            .setPrettyPrinting()
+            .create();
+
+    private final @NotNull String basePath;
+    private final @NotNull File baseFolder;
+
+    /**
+     * Constructs a new JDB instance with the specified base path.
+     *
+     * @param basePath the base directory path where documents will be stored
+     */
+    public JDB(@NotNull String basePath) {
+        this.basePath = basePath;
+        this.baseFolder = new File(basePath);
+    }
+
+    /**
+     * Retrieves a document from the specified path, deserializing it into the given class type.
+     *
+     * @param <T>   the type of the object to be returned
+     * @param path  the relative path (excluding .json extension) where the document is located
+     * @param clazz the class type to which the document should be deserialized
+     * @return a JDocument containing the deserialized object and its path, or null if the file does not exist
+     * @throws IOException if an I/O error occurs during file reading
+     */
+    public <T> T get(@NotNull String path, @NotNull Class<T> clazz) throws IOException {
+        File file = new File(baseFolder, basePath + path + ".json");
+        if (!file.exists()) {
+            return null;
+        }
+
+        BufferedReader bufferedReader = Files.newBufferedReader(file.toPath());
+
+        return GSON.fromJson(bufferedReader, clazz);
+    }
+
+    /**
+     * Retrieves all documents from the specified directory path, deserializing them into the given class type.
+     *
+     * @param <T>   the type of objects to be returned
+     * @param path  the relative directory path containing the documents
+     * @param clazz the class type to which the documents should be deserialized
+     * @return a List of JDocument objects containing the deserialized objects and their paths, or null if the directory or files do not exist
+     * @throws IOException if an I/O error occurs during file reading
+     */
+    public <T> List<T> getAll(@NotNull String path, @NotNull Class<T> clazz) throws IOException {
+        File folder = new File(baseFolder, basePath + path);
+        if (!folder.exists()) {
+            return new ArrayList<>();
+        }
+
+        File[] files = folder.listFiles();
+        if (files == null) {
+            return new ArrayList<>();
+        }
+
+        List<T> documents = new ArrayList<>(files.length);
+        for (File file : files) {
+            documents.add(get(path + "/" + file.getName().replace(".json", ""), clazz));
+        }
+
+        return documents;
+    }
+
+    /**
+     * Saves the given value as a document at the specified path.
+     *
+     * @param <T>   the type of the object to be saved
+     * @param path  the relative path (excluding .json extension) where the document will be saved
+     * @param value the object to be saved as a JSON document
+     * @throws IOException if an I/O error occurs during file writing
+     */
+    public <T> void set(@NotNull String path, @NotNull T value) throws IOException {
+        File file = new File(baseFolder, basePath + path + ".json");
+
+        if (!file.exists()) {
+            file.getParentFile().mkdirs();
+            file.createNewFile();
+        }
+
+        String json = GSON.toJson(value);
+
+        Files.write(file.toPath(), json.getBytes());
+    }
+
+    /**
+     * Deletes the document(s) at the specified path.
+     *
+     * @param path the relative path (excluding .json extension) where the document(s) are located
+     */
+    public void delete(@NotNull String path) {
+        File file = new File(baseFolder, basePath + path + ".json");
+        if (file.exists()) {
+            file.delete();
+        }
+    }
+}