Update exception handling config in samples

Closes gh-1204

samples/demo-authorizationserver/src/main/java/sample/config/AuthorizationServerConfig.java

@@ -30,6 +30,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
+import org.springframework.http.MediaType;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.datasource.embedded.EmbeddedDatabase;
 import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
@@ -55,6 +56,7 @@ import org.springframework.security.oauth2.server.authorization.token.JwtEncodin
 import org.springframework.security.oauth2.server.authorization.token.OAuth2TokenCustomizer;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.LoginUrlAuthenticationEntryPoint;
+import org.springframework.security.web.util.matcher.MediaTypeRequestMatcher;
 
 /**
  * @author Joe Grandja
@@ -116,8 +118,11 @@ public class AuthorizationServerConfig {
 
 		// @formatter:off
 		http
-			.exceptionHandling(exceptions ->
-				exceptions.authenticationEntryPoint(new LoginUrlAuthenticationEntryPoint("/login"))
+			.exceptionHandling((exceptions) -> exceptions
+				.defaultAuthenticationEntryPointFor(
+					new LoginUrlAuthenticationEntryPoint("/login"),
+					new MediaTypeRequestMatcher(MediaType.TEXT_HTML)
+				)
 			)
 			.oauth2ResourceServer(oauth2ResourceServer ->
 				oauth2ResourceServer.jwt(Customizer.withDefaults()));