Request method 'POST' not supported when #EnableOAuth2Sso - spring-security

Question

I am receiving a Request method 'POST' not supported error when I #EnableOAuth2Sso on my Spring Boot 1.5.9 / Angular 5 app.
GET requests work fine, and the JSESSIONID cookie looks like it's setting itself just fine on the front-end. Cookie is getting passed with all requests, and matches.
In the Response Header: Status Code: 405 Allow: GET, HEAD
This is my first Stack Overflow question, I've done all of my usual sleuthing and can't seem to get to the bottom of this one. I apologize in advance for any oversights in my asking / formatting of this question.
#SpringBootApplication
#EnableOAuth2Sso
#EnableOAuth2Client
public class CompanyApplication {
public static void main(String[] args) {
SpringApplication.run(CompanyApplication.class, args);
}
}
Relevant Controller
#RestController
#RequestMapping("api")
public class CompanyController {
#Autowired
CompanyRepository companyRepository;
#Autowired
ContactRepository contactRepository;
#PostMapping("companies")
public Company createCompany(#Valid #RequestBody Company company) {
logger.info("*** Starting POST request of company name: {}", company.getName());
company = updateContacts(company); // pass updated contact info into the Contact DB
companyRepository.save(company);
logger.info("*** Successful POST request of company: {}, ID: {},", company.getName(), company.getId());
return company;
}
Config settings:
security.oauth2.client.clientId=myID
security.oauth2.client.clientSecret=mySecret
security.oauth2.client.accessTokenUri=https://myserver.com/connect/token
security.oauth2.client.userAuthorizationUri=https://myserver.com/connect/authorize
security.oauth2.client.scope=openid,profile,email
security.oauth2.resource.userInfoUri=https://myserver.com/connect/userinfo
Angular service:
public updateCompany( companyData: Company ) {
return this.http.post(this.url, companyData);
}
Edit:
I followed the advice of #theLearner below, but still wanted to add CSRF (XSRF) protection. This is how I ended up doing it:
In app.module.ts add HttpClientXsrfModule to imports (I'm on Angular 5).
Remove #EnableOAuth2Sso from root CompanyApp class.
Config as follows:
#Configuration
#EnableOAuth2Sso
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
http.
authorizeRequests().anyRequest().authenticated().
and().
csrf().csrfTokenRepository(CookieCsrfTokenRepository.withHttpOnlyFalse());
}
}

Answer 1

There are following things you need to do.
In application properties add this config:
security.oauth2.resource.filter-order=3
More info about this is here.
Since you have not posted your Spring security config yet, not sure how is it right now. But it should look like this:
#Configuration
#EnableOAuth2Sso
public class WebSecurityConfigurer extends WebSecurityConfigurerAdapter {
#Override
protected void configure(HttpSecurity http) throws Exception {
http.csrf().disable() // or replace this with tour csrf token repository
.authorizeRequests()
.anyRequest().authenticated();
}
This SO post explains if #EnableOauth2Sso is not used carefully it can really mess up entire security configuratiin