Système de synchronisation de l'information entre FileFrontEnd<>StorBackEnd -> implémentation de AppData + ajout de la bibliothèque GSON à build.gradle

app/build.gradle

@@ -22,6 +22,8 @@ dependencies {
 
     // This dependency is used by the application.
     implementation 'com.google.guava:guava:30.1-jre'
+    // Use gson to serialize/deserialize json files
+    implementation 'com.google.code.gson:gson:2.9.0'
 }
 
 application {

app/src/main/java/lightcontainer/storage/AppData.java

@@ -0,0 +1,132 @@
+package lightcontainer.storage;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * AppData represents the database of the FileFrontEnd program.
+ * It contains an AppConfig instance and a collection of Users.
+ *
+ * @author Maximilien LEDOUX <m.ledoux@student.helmo.be>
+ * @version 1.0
+ * @see AppConfig
+ * @see User
+ * @since 1.0
+ */
+public class AppData {
+
+    private static AppData instance = null;
+    private AppConfig appConfig;
+    private final Map<String, User> users;
+
+
+    /**
+     * Constructs a new instance of AppData.
+     * Sets appConfig to null and creates a new Hashmap of users.
+     */
+    private AppData() {
+        this.appConfig = null;
+        this.users = new HashMap<>();
+    }
+
+    /**
+     * @return An instance of this class. Always returns the same instance.
+     */
+    public static AppData getInstance() {
+        if (instance == null) {
+            instance = new AppData();
+        }
+        return instance;
+    }
+
+    /**
+     * @return The AppConfig
+     */
+    public AppConfig getAppConfig() {
+        return appConfig;
+    }
+
+    /**
+     * Sets the AppConfig. This method sets the AppConfig for once and for all.
+     * It is locked after first call.
+     *
+     * @param appConfig The network configuration of the program.
+     */
+    public void setAppConfig(AppConfig appConfig) {
+        if (this.appConfig == null) {
+            this.appConfig = appConfig;
+        }
+    }
+
+    /**
+     * @param userName The name of the user.
+     * @return The user corresponding to userName, null otherwise.
+     */
+    public User getUser(String userName) {
+        return this.users.get(userName);
+    }
+
+    /**
+     * Use this method when a user signs up.
+     *
+     * @param user The user to add.
+     * @return True if the user was added. False if a user with the same name already exists.
+     */
+    public boolean addUser(User user) {
+        if (this.users.containsKey(user.getName())) {
+            return false;
+        } else {
+            this.users.put(user.getName(), user);
+            return true;
+        }
+    }
+
+    /**
+     * @param fileName The name of the file
+     * @param user     The user
+     * @return The file corresponding to the given name and belonging to the user. Null if the user cannot be found or the file cannot be found
+     * @deprecated Maybe not useful. DO NOT USE FOR THE TIME BEING
+     */
+    public File getFileOf(String fileName, User user) {
+        return this.users.get(user.getName()).getFile(fileName);
+    }
+
+    /**
+     * Call this method after receiving SAVEFILE_OK from the StorBackEnd.
+     * Do NOT call when receiving SAVEFILE_ERROR, or it will break the system's synchronization.
+     * <p>
+     * Adds the file of for a specific user.
+     * True indicates the success of the operation.
+     * False indicates the failure of the operation.
+     *
+     * @param file The file to add
+     * @param user The user who wants to add the file
+     * @return True if the user is found and a file with the same name doesn't already exist for this user. False otherwise.
+     */
+    public boolean addFileFor(File file, User user) {
+        if (!this.users.containsKey(user.getName())) {
+            return false;
+        } else {
+            return this.users.get(user.getName()).addFile(file);
+        }
+    }
+
+    /**
+     * Call this method after receiving REMOVEFILE_OK from the StorBackEnd.
+     * Do NOT call when receiving REMOVEFILE_ERROR, or it will break the system's synchronization.
+     * Deletes the file of for a specific user.
+     * True indicates the success of the operation.
+     * False indicates the failure of the operation.
+     *
+     * @param fileName The name of the file to delete
+     * @param user     The user who wants to delete the file
+     * @return True if the user is found and the file was deleted. False otherwise.
+     */
+    public boolean deleteFileOf(String fileName, User user) {
+        if (!this.users.containsKey(user.getName())) {
+            return false;
+        } else {
+            return this.users.get(user.getName()).deleteFile(fileName);
+        }
+    }
+}