Moved everything related to the properties to its own manager

Signed-off-by: Louis Vallat <louis@louis-vallat.xyz>

src/main/java/xyz/vallat/louis/database/DBManager.java

@@ -4,8 +4,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import xyz.vallat.louis.MovieQuoteBot;
 
-import java.io.IOException;
-import java.security.NoSuchAlgorithmException;
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
@@ -13,6 +11,7 @@ import java.sql.Statement;
 
 import static xyz.vallat.louis.database.LanguageManager.importLanguageIfNeeded;
 import static xyz.vallat.louis.database.LanguageManager.initializeLanguages;
+import static xyz.vallat.louis.database.PropertyManager.initializeProperties;
 
 public final class DBManager {
 
@@ -34,7 +33,7 @@ public final class DBManager {
     }
 
     // TODO: EXIT CODES AS ENUM
-    private static Connection getConnection() {
+    public static Connection getConnection() {
         try {
             return DriverManager.getConnection("jdbc:" + CONNECTION_PREFIX + "://" + HOST + ":" + PORT + "/"
                     + DATABASE, USERNAME, PASSWORD);
@@ -53,8 +52,7 @@ public final class DBManager {
 
     public static void initDatabase() {
         logger.debug("Initializing database if not done yet.");
-        Connection connection = getConnection();
+        try (Connection connection = getConnection()) {
-        try {
             initializeProperties(connection);
             initializeLanguages(connection);
             initializeFilm(connection);
@@ -64,23 +62,6 @@ public final class DBManager {
         } catch (SQLException e) {
             logger.error("An error happened while initializing the database. Reason: {}", e.getMessage());
             System.exit(5);
-        } catch (NoSuchAlgorithmException | IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    private static void initializeProperties(Connection connection) throws SQLException {
-        logger.debug("Creating properties table.");
-        try (Statement stmt = connection.createStatement()) {
-            String query = "CREATE TABLE IF NOT EXISTS properties\n" +
-                    "(\n" +
-                    "    id        int GENERATED ALWAYS AS IDENTITY,\n" +
-                    "    app_key   text NOT NULL,\n" +
-                    "    app_value text NOT NULL,\n" +
-                    "    PRIMARY KEY (id),\n" +
-                    "    UNIQUE (app_key)\n" +
-                    ");";
-            stmt.executeUpdate(query);
         }
     }
 

src/main/java/xyz/vallat/louis/database/LanguageManager.java

@@ -16,6 +16,9 @@ import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Statement;
 
+import static xyz.vallat.louis.database.PropertyManager.getPropertyValue;
+import static xyz.vallat.louis.database.PropertyManager.saveProperty;
+
 public final class LanguageManager {
 
     private static final Logger logger = LoggerFactory.getLogger(LanguageManager.class.getCanonicalName());
@@ -25,35 +28,22 @@ public final class LanguageManager {
     private LanguageManager() {
     }
 
-    public static void importLanguageIfNeeded(Connection connection) throws SQLException, IOException, NoSuchAlgorithmException {
+    public static void importLanguageIfNeeded(Connection connection) {
+        String storedHash = "";
+        try {
             logger.debug("Checking if we need to import languages again.");
-        String storedHash = getStoredHash(connection);
+            storedHash = getPropertyValue(HASH_KEY);
             logger.debug("Stored hash was '{}'.", storedHash);
             String actualHash = getActualHash();
             logger.debug("Actual hash is '{}'.", actualHash);
             logger.info("Importing new language file.");
             if (!storedHash.equals(actualHash)) importLanguageFile(connection);
             logger.debug("Saving new hash in database.");
-        saveNewHash(connection, actualHash);
+            saveProperty(HASH_KEY, actualHash);
-    }
+        } catch (SQLException | IOException | NoSuchAlgorithmException e) {
-
+            logger.error("Cannot update the languages right now. Reason: {}", e.getMessage());
-    private static void saveNewHash(Connection connection, String actualHash) throws SQLException {
+            if (storedHash.isEmpty()) System.exit(7);
-        String query;
+            logger.warn("Using language already in database. Please contact this bot's administrator to fix this issue.");
-        if (doesPropertyExist(connection, HASH_KEY)) query = "UPDATE properties SET app_value = ? WHERE app_key = ?;";
-        else query = "INSERT INTO properties(app_value, app_key) VALUES (?, ?)";
-        try (PreparedStatement stmt = connection.prepareStatement(query)) {
-            stmt.setString(1, actualHash);
-            stmt.setString(2, HASH_KEY);
-            stmt.execute();
-        }
-    }
-
-    private static boolean doesPropertyExist(Connection connection, String key) throws SQLException {
-        String query = "SELECT id FROM properties WHERE app_key=?;";
-        try (PreparedStatement stmt = connection.prepareStatement(query)){
-            stmt.setString(1, key);
-            stmt.execute();
-            return stmt.getResultSet().next();
         }
     }
 
@@ -100,8 +90,8 @@ public final class LanguageManager {
     }
 
     private static boolean isInDatabase(Connection connection, String alpha3b) throws SQLException {
-        String query = "SELECT id FROM languages WHERE alpha3_b = ?;";
+        String query = "SELECT 1 FROM languages WHERE alpha3_b = ?;";
-        try (PreparedStatement stmt = connection.prepareStatement(query)){
+        try (PreparedStatement stmt = connection.prepareStatement(query)) {
             stmt.setString(1, alpha3b);
             stmt.execute();
             return stmt.getResultSet().next();
@@ -121,17 +111,6 @@ public final class LanguageManager {
         }
     }
 
-    private static String getStoredHash(Connection connection) throws SQLException {
-        logger.debug("Getting current hash");
-        String query = "SELECT app_value FROM properties WHERE app_key=?;";
-        try (PreparedStatement stmt = connection.prepareStatement(query)) {
-            stmt.setString(1, HASH_KEY);
-            stmt.execute();
-            if (stmt.getResultSet().next()) return stmt.getResultSet().getString(1);
-            else return "";
-        }
-    }
-
     private static String getActualHash() throws NoSuchAlgorithmException, IOException {
         logger.debug("Computing the actual language source file's hash.");
         return getFileChecksum(MessageDigest.getInstance("MD5"));

src/main/java/xyz/vallat/louis/database/PropertyManager.java

@@ -0,0 +1,66 @@
+package xyz.vallat.louis.database;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+public final class PropertyManager {
+
+    private static final Logger logger = LoggerFactory.getLogger(PropertyManager.class.getCanonicalName());
+
+    private PropertyManager() {
+    }
+
+    public static void saveProperty(String key, String value) {
+        logger.debug("Saving property '{}' with value '{}'.", key, value);
+        try (Connection connection = DBManager.getConnection()) {
+            String query;
+            if (getPropertyValue(key) == null)
+                query = "UPDATE properties SET app_value = ? WHERE app_key = ?;";
+            else query = "INSERT INTO properties(app_value, app_key) VALUES (?, ?)";
+            try (PreparedStatement stmt = connection.prepareStatement(query)) {
+                stmt.setString(1, value);
+                stmt.setString(2, key);
+                stmt.execute();
+            }
+        } catch (SQLException e) {
+            logger.error("Cannot save properties right now. Reason: {}", e.getMessage());
+        }
+    }
+
+    public static String getPropertyValue(String key) {
+        logger.debug("Checking if property '{}' exists.", key);
+        String query = "SELECT app_value FROM properties WHERE app_key = ?;";
+        try (Connection connection = DBManager.getConnection()) {
+            try (PreparedStatement stmt = connection.prepareStatement(query)) {
+                stmt.setString(1, key);
+                stmt.execute();
+                if (stmt.getResultSet().next()) return stmt.getResultSet().getString(1);
+            }
+            return null;
+        } catch (SQLException e) {
+            logger.error("Cannot get property right now. Reason: {}.", e.getMessage());
+            System.exit(6);
+        }
+        return null;
+    }
+
+    public static void initializeProperties(Connection connection) throws SQLException {
+        logger.debug("Creating properties table.");
+        try (Statement stmt = connection.createStatement()) {
+            String query = "CREATE TABLE IF NOT EXISTS properties\n" +
+                    "(\n" +
+                    "    id        int GENERATED ALWAYS AS IDENTITY,\n" +
+                    "    app_key   text NOT NULL,\n" +
+                    "    app_value text NOT NULL,\n" +
+                    "    PRIMARY KEY (id),\n" +
+                    "    UNIQUE (app_key)\n" +
+                    ");";
+            stmt.executeUpdate(query);
+        }
+    }
+}