BAEL-3569: Jersey RESTful Web Services with Spring Security OAuth2 (#9949)

* BAEL-3569 Jersey REST service with Spring Security OAuth

* BAEL-3569 Fix indentation spaces

spring-5-security-oauth/src/main/java/com/baeldung/jersey/JerseyResource.java

@@ -0,0 +1,30 @@
+package com.baeldung.jersey;
+
+import org.springframework.security.oauth2.client.authentication.OAuth2AuthenticationToken;
+import org.springframework.security.oauth2.core.OAuth2AuthenticatedPrincipal;
+
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.SecurityContext;
+
+@Path("/")
+public class JerseyResource {
+    @GET
+    @Path("login")
+    @Produces(MediaType.TEXT_HTML)
+    public String login() {
+        return "Log in with <a href=\"/oauth2/authorization/github\">GitHub</a>";
+    }
+
+    @GET
+    @Produces(MediaType.TEXT_PLAIN)
+    public String home(@Context SecurityContext securityContext) {
+        OAuth2AuthenticationToken authenticationToken = (OAuth2AuthenticationToken) securityContext.getUserPrincipal();
+        OAuth2AuthenticatedPrincipal authenticatedPrincipal = authenticationToken.getPrincipal();
+        String userName = authenticatedPrincipal.getAttribute("login");
+        return "Hello " + userName;
+    }
+}