Spring Security form login only offers application/json req body type. fixes #1931

Author: bnasslahsen

springdoc-openapi-starter-common/src/main/java/org/springdoc/core/configuration/SpringDocSecurityConfiguration.java

@@ -38,6 +38,7 @@
 import io.swagger.v3.oas.models.parameters.RequestBody;
 import io.swagger.v3.oas.models.responses.ApiResponse;
 import io.swagger.v3.oas.models.responses.ApiResponses;
+import org.apache.commons.lang3.reflect.FieldUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springdoc.core.customizers.OpenApiCustomizer;
@@ -58,6 +59,7 @@
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter;
 import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
+import org.springframework.security.web.authentication.ui.DefaultLoginPageGeneratingFilter;
 import org.springframework.security.web.context.AbstractSecurityWebApplicationInitializer;
 import org.springframework.security.web.util.matcher.AntPathRequestMatcher;
 
@@ -110,13 +112,31 @@ OpenApiCustomizer springSecurityLoginEndpointCustomiser(ApplicationContext appli
 									.filter(UsernamePasswordAuthenticationFilter.class::isInstance)
 									.map(UsernamePasswordAuthenticationFilter.class::cast)
 									.findAny();
+					Optional<DefaultLoginPageGeneratingFilter> optionalDefaultLoginPageGeneratingFilter =
+							filterChain.getFilters().stream()
+									.filter(DefaultLoginPageGeneratingFilter.class::isInstance)
+									.map(DefaultLoginPageGeneratingFilter.class::cast)
+									.findAny();
 					if (optionalFilter.isPresent()) {
 						UsernamePasswordAuthenticationFilter usernamePasswordAuthenticationFilter = optionalFilter.get();
 						Operation operation = new Operation();
 						Schema<?> schema = new ObjectSchema()
 								.addProperty(usernamePasswordAuthenticationFilter.getUsernameParameter(), new StringSchema())
 								.addProperty(usernamePasswordAuthenticationFilter.getPasswordParameter(), new StringSchema());
-						RequestBody requestBody = new RequestBody().content(new Content().addMediaType(org.springframework.http.MediaType.APPLICATION_JSON_VALUE, new MediaType().schema(schema)));
+						String mediaType = org.springframework.http.MediaType.APPLICATION_JSON_VALUE;
+						if(optionalDefaultLoginPageGeneratingFilter.isPresent()){
+							DefaultLoginPageGeneratingFilter defaultLoginPageGeneratingFilter = optionalDefaultLoginPageGeneratingFilter.get();
+							Field formLoginEnabledField = FieldUtils.getDeclaredField(DefaultLoginPageGeneratingFilter.class, "formLoginEnabled", true);
+							try {
+								boolean formLoginEnabled = (boolean) formLoginEnabledField.get(defaultLoginPageGeneratingFilter);
+								if(formLoginEnabled)
+									mediaType = org.springframework.http.MediaType.APPLICATION_FORM_URLENCODED_VALUE;
+							}
+							catch (IllegalAccessException e) {
+								LOGGER.warn(e.getMessage());
+							}
+						}
+						RequestBody requestBody = new RequestBody().content(new Content().addMediaType(mediaType, new MediaType().schema(schema)));
 						operation.requestBody(requestBody);
 						ApiResponses apiResponses = new ApiResponses();
 						apiResponses.addApiResponse(String.valueOf(HttpStatus.OK.value()), new ApiResponse().description(HttpStatus.OK.getReasonPhrase()));

springdoc-openapi-tests/springdoc-openapi-security-tests/src/test/resources/results/app8.json

@@ -22,7 +22,7 @@
         ],
         "requestBody": {
           "content": {
-            "application/json": {
+            "application/x-www-form-urlencoded": {
               "schema": {
                 "type": "object",
                 "properties": {