MESSAGE:java.net.ConnectException: Connection refused: connect

public class ExampleJdbc {
	static final String DB_URL = "jdbc:mysql://localhost:3306/agenda";
	static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
	
	static final String USER = "root";
	static final String PASS = "12345";

	public static void main(String[] args) {
		
		Connection connection = null;
		PreparedStatement stmt = null;
		
		try {
			Class.forName("com.mysql.jdbc.Driver");
			
			System.out.println("Connecting to database...");
			connection = DriverManager.getConnection(DB_URL,USER,PASS);
			
			System.out.println("Creating statement...");
			stmt = (PreparedStatement) connection.createStatement();

			FileReader arquivo = new FileReader("C:/Curso_Java/arquivo.txt");
			BufferedReader lerArquivo = new BufferedReader(arquivo);
			String linha = lerArquivo.readLine();
			String dados[] = new String[2];

			while (linha != null) {

				StringTokenizer st = new StringTokenizer(linha);
				dados[0] = st.nextToken();
				dados[1] = st.nextToken();

				stmt.executeUpdate("insert into contatos (id,nome,telefone,email,data) values ('" + dados[0] + "','"
						+ dados[1] + "',')");

				linha = lerArquivo.readLine();
			}
			arquivo.close();
			stmt.close();
			connection.close();

			JOptionPane.showMessageDialog(null, "Sucesso!!");
			System.out.println("MySQL JDBC Driver Registered!");

		} catch (Exception e) {
			JOptionPane.showMessageDialog(null, e.getMessage());
			System.out.println("Connection failed.");
		}
	}

}