Take a look at the following code. Quite straightforward, isn't it?. This is where we let  know where our CAS server is running. When a user tries to log in, the application will be redirected to this URL:

@Bean
public AuthenticationEntryPoint authenticationEntryPoint() {
    CasAuthenticationEntryPoint casAuthEntryPoint = new CasAuthenticationEntryPoint();
    casAuthEntryPoint.setLoginUrl("https://localhost:6443/cas/login");
    casAuthEntryPoint.setServiceProperties(serviceProperties());
    return casAuthEntryPoint;
}