java.sql.SQLRecoverableException: Error de E/S: The Network Adapter could not establish the connection
    at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:489)
    at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:553)
    at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:254)
    at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
    at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:528)
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:678)
    at java.sql/java.sql.DriverManager.getConnection(DriverManager.java:229)
    at connection.ConexionOracle.conectar(ConexionOracle.java:31)
    at connection.ConexionOracle.consult(ConexionOracle.java:73)
    at connection.ConexionOracle.getColumn(ConexionOracle.java:60)
    at view.JpanelCreate.<init>(JpanelCreate.java:35)
    at view.JpanelCRUD.<init>(JpanelCRUD.java:28)
    at view.JFrameMainWindow.<init>(JFrameMainWindow.java:18)
    at controller.Controller.<init>(Controller.java:13)
    at test.Runner.main(Runner.java:7)

public ConexionOracle conectar() {
        try {
            Class.forName("oracle.jdbc.OracleDriver");
            String BaseDeDatos = "jdbc:oracle:thin:@192.168.137.109:1521:xe";
            conexion = DriverManager.getConnection(BaseDeDatos, user,pass);
            if (conexion != null) {
                System.out.println("Conexion exitosa!");
            } else {
                System.out.println("Conexion fallida!");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return this;
    }