Fix/5662 default content type sba settings

spring-boot-admin-server-ui/src/main/java/de/codecentric/boot/admin/server/ui/config/AdminServerUiAutoConfiguration.java

@@ -18,24 +18,36 @@
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.Enumeration;
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import jakarta.servlet.Filter;
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletRequestWrapper;
+import jakarta.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.web.servlet.FilterRegistrationBean;
 import org.springframework.boot.webflux.autoconfigure.WebFluxProperties;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.Ordered;
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
+import org.springframework.web.filter.OncePerRequestFilter;
 import org.springframework.web.reactive.config.WebFluxConfigurer;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 import org.thymeleaf.spring6.templateresolver.SpringResourceTemplateResolver;
@@ -280,6 +292,78 @@ public de.codecentric.boot.admin.server.ui.web.servlet.HomepageForwardingFilter
 						homepageForwardingFilterConfig);
 			}
 
+			@Bean
+			public FilterRegistrationBean<Filter> sbaSettingsAcceptHeaderFilter() {
+				FilterRegistrationBean<Filter> registration = new FilterRegistrationBean<>(
+						new SbaSettingsAcceptHeaderFilter());
+				registration.addUrlPatterns(this.adminServer.path("/sba-settings.js"));
+				registration.setOrder(Ordered.HIGHEST_PRECEDENCE);
+				return registration;
+			}
+
+			private static final class SbaSettingsAcceptHeaderFilter extends OncePerRequestFilter {
+
+				@Override
+				protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
+						FilterChain filterChain) throws ServletException, IOException {
+					filterChain.doFilter(
+							shouldRewriteAcceptHeader(request) ? new AcceptHeaderRequestWrapper(request) : request,
+							response);
+				}
+
+				private static boolean shouldRewriteAcceptHeader(HttpServletRequest request) {
+					String accept = request.getHeader(HttpHeaders.ACCEPT);
+					if (accept == null || accept.isBlank()) {
+						return true;
+					}
+					try {
+						return MediaType.parseMediaTypes(accept)
+							.stream()
+							.allMatch((mediaType) -> "*".equals(mediaType.getType())
+									&& "*".equals(mediaType.getSubtype()));
+					}
+					catch (IllegalArgumentException ex) {
+						return false;
+					}
+				}
+
+			}
+
+			private static final class AcceptHeaderRequestWrapper extends HttpServletRequestWrapper {
+
+				private static final String ACCEPT = "application/javascript";
+
+				private AcceptHeaderRequestWrapper(HttpServletRequest request) {
+					super(request);
+				}
+
+				@Override
+				public String getHeader(String name) {
+					if (HttpHeaders.ACCEPT.equalsIgnoreCase(name)) {
+						return ACCEPT;
+					}
+					return super.getHeader(name);
+				}
+
+				@Override
+				public Enumeration<String> getHeaders(String name) {
+					if (HttpHeaders.ACCEPT.equalsIgnoreCase(name)) {
+						return Collections.enumeration(List.of(ACCEPT));
+					}
+					return super.getHeaders(name);
+				}
+
+				@Override
+				public Enumeration<String> getHeaderNames() {
+					List<String> names = Collections.list(super.getHeaderNames());
+					if (names.stream().noneMatch(HttpHeaders.ACCEPT::equalsIgnoreCase)) {
+						names.add(HttpHeaders.ACCEPT);
+					}
+					return Collections.enumeration(names);
+				}
+
+			}
+
 		}
 
 	}

spring-boot-admin-server-ui/src/test/java/de/codecentric/boot/admin/server/ui/AbstractAdminUiApplicationTest.java

@@ -135,6 +135,17 @@ public void should_contain_only_one_language() {
 		//@formatter:on
 	}
 
+	@Test
+	public void should_not_return_sba_settings_for_json_accept() {
+		//@formatter:off
+		this.webClient.get()
+					.uri("/sba-settings.js")
+					.accept(MediaType.APPLICATION_JSON)
+					.exchange()
+					.expectStatus().isEqualTo(HttpStatus.NOT_ACCEPTABLE);
+		//@formatter:on
+	}
+
 	@Test
 	public void should_return_defaults_for_pollTimers() {
 		//@formatter:off

spring-boot-admin-server-ui/src/test/java/de/codecentric/boot/admin/server/ui/AdminUiServletApplicationTest.java

@@ -29,6 +29,8 @@
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer;
 import org.springframework.security.web.SecurityFilterChain;
+import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 import de.codecentric.boot.admin.server.config.EnableAdminServer;
 
@@ -73,6 +75,16 @@ protected SecurityFilterChain filterChain(HttpSecurity http) {
 					.build();
 			}
 
+			@Bean
+			WebMvcConfigurer defaultJsonContentNegotiation() {
+				return new WebMvcConfigurer() {
+					@Override
+					public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
+						configurer.defaultContentType(MediaType.APPLICATION_JSON);
+					}
+				};
+			}
+
 		}
 
 	}