Resolve ambiguous handler mapping in SeedController

Override the `@PostMapping` path pattern in `SeedController` to exclude `.xml`
and `.json` suffixes, addressing a stricter behavior in Spring Boot compared
to regular Spring. This resolves a potential `IllegalStateException` caused by
ambiguous handler methods.

- Updated `doPost` endpoint path to use regex excluding `.xml` and `.json`.
- Prevents conflicts between JSON and XML payload handlers (`seedOrTruncateWithJsonPayload`
  and `seedOrTruncateWithXmlPayload`).
- Fixes mapping collision issues observed when calling endpoints like
  `/rest/seed/workspace:layer.xml` under Spring Boot.

This change ensures compatibility with Spring Boot's stricter handler mapping
rules while maintaining functionality consistent with the base `SeedController` logic.

src/apps/geoserver/gwc/src/test/java/org/geoserver/cloud/gwc/app/GeoWebCacheApplicationTest.java

@@ -10,6 +10,7 @@
 
 import com.google.gson.JsonElement;
 import com.google.gson.JsonParser;
+import java.net.URI;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -57,4 +58,31 @@ protected ResponseEntity<String> testGetRequestContentType(String uri, MediaType
         assertThat(response.getHeaders().getContentType()).isEqualTo(expected);
         return response;
     }
+
+    @Test
+    void testPostSeedDoesNotThrowAmbiguousHandlerMapping() {
+        String payload =
+                """
+                <seedRequest>
+                  <name>workspace:layer</name>
+                  <srs><number>3857</number></srs>
+                  <zoomStart>0</zoomStart>
+                  <zoomStop>8</zoomStop>
+                  <format>image/png</format>
+                  <type>reseed</type>
+                  <threadCount>2</threadCount>
+                </seedRequest>
+                """;
+        String uri = "/gwc/rest/seed/workspace:layer.xml";
+
+        ResponseEntity<String> response = restTemplate.postForEntity(URI.create(uri), payload, String.class);
+        HttpStatus statusCode = response.getStatusCode();
+        String body = response.getBody();
+
+        // SeedService will throw a 500 error when the layer is not found
+        // it's ok we just need to check it doesn't result in an "ambiguous handler mapping" error
+        // see org.geoserver.cloud.gwc.config.services.SeedController
+        assertThat(statusCode).isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR);
+        assertThat(body).contains("Unknown layer workspace:layer");
+    }
 }

src/gwc/services/src/main/java/org/geoserver/cloud/gwc/config/services/RESTConfigConfiguration.java

@@ -7,12 +7,14 @@
 import org.geoserver.catalog.Catalog;
 import org.geoserver.gwc.controller.GwcUrlHandlerMapping;
 import org.geoserver.gwc.layer.GWCGeoServerRESTConfigurationProvider;
+import org.geowebcache.rest.controller.SeedController;
 import org.geowebcache.rest.converter.GWCConverter;
 import org.geowebcache.util.ApplicationContextProvider;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.FilterType;
 
 /**
  * The original {@literal geowebcache-rest-context.xml}:
@@ -51,9 +53,16 @@
  */
 @Configuration(proxyBeanMethods = false)
 @ConditionalOnClass(GWCConverter.class)
-@ComponentScan(basePackages = "org.geowebcache.rest")
+@ComponentScan(
+        basePackages = "org.geowebcache.rest",
+        excludeFilters = @ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, classes = SeedController.class))
 public class RESTConfigConfiguration {
 
+    @Bean
+    org.geoserver.cloud.gwc.config.services.SeedController seedController() {
+        return new org.geoserver.cloud.gwc.config.services.SeedController();
+    }
+
     /**
      * The original {@literal geowebcache-rest-context.xml}:
      *

src/gwc/services/src/main/java/org/geoserver/cloud/gwc/config/services/SeedController.java

@@ -0,0 +1,46 @@
+/*
+ * (c) 2024 Open Source Geospatial Foundation - all rights reserved This code is licensed under the
+ * GPL 2.0 license, available at the root application directory.
+ */
+package org.geoserver.cloud.gwc.config.services;
+
+import java.io.InputStream;
+import java.util.Map;
+import javax.servlet.http.HttpServletRequest;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import org.springframework.web.bind.annotation.*;
+
+@Component
+@RestController
+@RequestMapping(path = "${gwc.context.suffix:}/rest")
+public class SeedController extends org.geowebcache.rest.controller.SeedController {
+
+    /**
+     *
+     * {@inheritDoc}
+     * <p>
+     * Override for the {@code path} pattern to exclude {@code .xml} and
+     * {@code .json} suffixes to avoid an exception like the following with
+     * {@link #seedOrTruncateWithJsonPayload} and
+     * {@link #seedOrTruncateWithXmlPayload}:
+     * <pre>
+     * <code>
+     * java.lang.IllegalStateException: Ambiguous handler methods mapped for '.../rest/seed/workspace:layer.xml': {
+     *   public org.springframework.http.ResponseEntity org.geoserver.cloud.gwc.config.services.SeedController.seedOrTruncateWithXmlPayload(...),
+     *   public org.springframework.http.ResponseEntity org.geoserver.cloud.gwc.config.services.SeedController.doPost(...)
+     *  }
+     * </code>
+     * </pre>
+     */
+    @Override
+    @PostMapping("/seed/{layer:^(?!.*\\.(?:xml|json)$).+}")
+    public ResponseEntity<?> doPost(
+            HttpServletRequest request,
+            InputStream inputStream,
+            @PathVariable String layer,
+            @RequestParam Map<String, String> params) {
+
+        return super.doPost(request, inputStream, layer, params);
+    }
+}