Java – Cannot connect to Oracle DB from Java – ORA-12560: TNS:protocol adapter error

Try using the type IV JDBC driver instead of OCI if you can. The thin url looks like this:

jdbc:oracle:thin:@host[:port]/service

I'd try code that looked more like this (fill in your defaults for the driver, URL, username, and password):

    package persistence;

    import java.sql.*;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;

    public class DatabaseUtils
    {

        private static final String DEFAULT_DRIVER = "";
        private static final String DEFAULT_URL = "";
        private static final String DEFAULT_USERNAME = "";
        private static final String DEFAULT_PASSWORD = "";

        public static void main(String[] args)
        {
            String driver = ((args.length > 0) ? args[0] : DEFAULT_DRIVER);
            String url = ((args.length > 1) ? args[1] : DEFAULT_URL);
            String username = ((args.length > 2) ? args[2] : DEFAULT_USERNAME);
            String password = ((args.length > 3) ? args[3] : DEFAULT_PASSWORD);

            Connection connection = null;

            try
            {
                connection = createConnection(driver, url, username, password);
                DatabaseMetaData meta = connection.getMetaData();
                System.out.println(meta.getDatabaseProductName());
                System.out.println(meta.getDatabaseProductVersion());
            }
            catch (Exception e)
            {
                e.printStackTrace(); 
            }
            finally
            {
                close(connection);
            }
        }

        public static Connection createConnection(String driver, String url, String username, String password) throws ClassNotFoundException, SQLException
        {
            Class.forName(driver);

            if ((username == null) || (password == null) || (username.trim().length() == 0) || (password.trim().length() == 0))
            {
                return DriverManager.getConnection(url);
            }
            else
            {
                return DriverManager.getConnection(url, username, password);
            }
        }

        public static void close(Connection connection)
        {
            try
            {
                if (connection != null)
                {
                    connection.close();
                }
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
        }


        public static void close(Statement st)
        {
            try
            {
                if (st != null)
                {
                    st.close();
                }
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
        }

        public static void close(ResultSet rs)
        {
            try
            {
                if (rs != null)
                {
                    rs.close();
                }
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
        }

        public static void rollback(Connection connection)
        {
            try
            {
                if (connection != null)
                {
                    connection.rollback();
                }
            }
            catch (SQLException e)
            {
                e.printStackTrace();
            }
        }

        public static List<Map<String, Object>> map(ResultSet rs) throws SQLException
        {
            List<Map<String, Object>> results = new ArrayList<Map<String, Object>>();

            try
            {
                if (rs != null)
                {
                    ResultSetMetaData meta = rs.getMetaData();
                    int numColumns = meta.getColumnCount();
                    while (rs.next())
                    {
                        Map<String, Object> row = new HashMap<String, Object>();
                        for (int i = 1; i <= numColumns; ++i)
                        {
                            String name = meta.getColumnName(i);
                            Object value = rs.getObject(i);
                            row.put(name, value);
                        }
                        results.add(row);
                    }
                }
            }
            finally
            {
                close(rs);
            }

            return results;
        }
    }