AuthenticationUserIdExtractor.java

package org.springframework.social.showcase.security;

import org.springframework.security.core.Authentication;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.social.UserIdSource;

public class AuthenticationUserIdExtractor implements UserIdSource {
	@Override
	public String getUserId() {
		Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
		if (authentication == null) {
			throw new IllegalStateException("Unable to get a ConnectionRepository: no user signed in");
		}
		return authentication.getName();
	}
}