MrUltimateLibrary Source

package eu.mrneznamy.mrultimatelibrary.database;

import java.io.File;
import java.sql.*;
import java.util.function.Consumer;

/**
 * SQLite Database implementation
 */
public class MrLibSQLite implements MrLibDatabase {
    
    private final File databaseFile;
    private Connection connection;
    
    public MrLibSQLite(File databaseFile) {
        this.databaseFile = databaseFile;
    }
    
    @Override
    public boolean connect() {
        try {
            if (connection != null && !connection.isClosed()) {
                return true;
            }
            
            
            if (!databaseFile.getParentFile().exists()) {
                databaseFile.getParentFile().mkdirs();
            }
            
            String url = "jdbc:sqlite:" + databaseFile.getAbsolutePath();
            connection = DriverManager.getConnection(url);
            return true;
        } catch (SQLException e) {
            e.printStackTrace();
            return false;
        }
    }
    
    @Override
    public void disconnect() {
        try {
            if (connection != null && !connection.isClosed()) {
                connection.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    @Override
    public boolean isConnected() {
        try {
            return connection != null && !connection.isClosed();
        } catch (SQLException e) {
            return false;
        }
    }
    
    @Override
    public Connection getConnection() {
        try {
            if (connection == null || connection.isClosed()) {
                connect();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }
    
    @Override
    public int executeUpdate(String sql, Object... params) {
        try (PreparedStatement stmt = prepareStatement(sql, params)) {
            return stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
            return 0;
        }
    }
    
    @Override
    public void executeQuery(String sql, Consumer<ResultSet> callback, Object... params) {
        try (PreparedStatement stmt = prepareStatement(sql, params);
             ResultSet rs = stmt.executeQuery()) {
            callback.accept(rs);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    @Override
    public ResultSet executeQuerySync(String sql, Object... params) {
        try {
            PreparedStatement stmt = prepareStatement(sql, params);
            return stmt.executeQuery();
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }
    
    @Override
    public void createTable(String tableName, String columns) {
        String sql = "CREATE TABLE IF NOT EXISTS " + tableName + " (" + columns + ")";
        executeUpdate(sql);
    }
    
    @Override
    public boolean tableExists(String tableName) {
        try {
            DatabaseMetaData meta = getConnection().getMetaData();
            ResultSet rs = meta.getTables(null, null, tableName, new String[]{"TABLE"});
            return rs.next();
        } catch (SQLException e) {
            return false;
        }
    }
    
    private PreparedStatement prepareStatement(String sql, Object... params) throws SQLException {
        PreparedStatement stmt = getConnection().prepareStatement(sql);
        for (int i = 0; i < params.length; i++) {
            stmt.setObject(i + 1, params[i]);
        }
        return stmt;
    }
}