Fixed a bug where complex query method parameters that aren't managed by repositories were causing the parameter processing to short-circuit to a 404 error. Replaced that method call with a different one that simple returns a boolean if a type is managed by a repository so the if/else chain can continue on to the ConversionService.

spring-data-rest-repository/src/main/java/org/springframework/data/rest/repository/RepositoryExporterSupport.java

@@ -71,6 +71,36 @@ public abstract class RepositoryExporterSupport<S extends RepositoryExporterSupp
     return (S)this;
   }
 
+  /**
+   * Does a Repository exist for this name?
+   *
+   * @param name
+   *
+   * @return true
+   */
+  public boolean hasRepositoryMetadataFor(String name) {
+    try {
+      return (null != repositoryMetadataFor(name));
+    } catch(RepositoryNotFoundException ignored) {
+      return false;
+    }
+  }
+
+  /**
+   * Is there a Repository responsible for this domain type?
+   *
+   * @param domainType
+   *
+   * @return
+   */
+  public boolean hasRepositoryMetadataFor(Class<?> domainType) {
+    try {
+      return (null != repositoryMetadataFor(domainType));
+    } catch(RepositoryNotFoundException ignored) {
+      return false;
+    }
+  }
+
   /**
    * Find {@link RepositoryMetadata} for the {@link org.springframework.data.repository.Repository} exported under this
    * name.

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryRestController.java

@@ -537,11 +537,11 @@ public class RepositoryRestController
         continue;
       }
 
-      RepositoryMetadata paramRepoMeta;
       if(String.class.isAssignableFrom(paramTypes[i])) {
         // Param type is a String
         paramVals[i] = queryVal;
-      } else if(null != (paramRepoMeta = repositoryMetadataFor(paramTypes[i]))) {
+      } else if(hasRepositoryMetadataFor(paramTypes[i])) {
+        RepositoryMetadata paramRepoMeta = repositoryMetadataFor(paramTypes[i]);
         // Complex parameter is a managed type
         Serializable id = stringToSerializable(queryVal,
                                                (Class<Serializable>)paramRepoMeta.entityMetadata()