For manager-based employee aggregate, swap out default "self link.

Resolves: #29

hypermedia/src/main/java/org/springframework/hateoas/examples/EmployeeController.java

@@ -15,11 +15,16 @@
  */
 package org.springframework.hateoas.examples;
 
+import static org.springframework.hateoas.server.mvc.WebMvcLinkBuilder.*;
+
+import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 
 import org.springframework.hateoas.CollectionModel;
 import org.springframework.hateoas.EntityModel;
+import org.springframework.hateoas.IanaLinkRelations;
+import org.springframework.hateoas.Link;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -80,7 +85,21 @@ class EmployeeController {
 	@GetMapping("/managers/{id}/employees")
 	public ResponseEntity<CollectionModel<EntityModel<Employee>>> findEmployees(@PathVariable long id) {
 
-		return ResponseEntity.ok(assembler.toCollectionModel(repository.findByManagerId(id)));
+		CollectionModel<EntityModel<Employee>> collectionModel = assembler
+				.toCollectionModel(repository.findByManagerId(id));
+
+		List<Link> newLinks = collectionModel.getLinks().stream() //
+				.map(link -> {
+					// Replace the "self" link so it links back to here
+					if (link.getRel() == IanaLinkRelations.SELF) {
+						return linkTo(methodOn(EmployeeController.class).findEmployees(id)).withSelfRel();
+					} else {
+						return link;
+					}
+				}) //
+				.collect(Collectors.toList());
+
+		return ResponseEntity.ok(new CollectionModel<>(collectionModel.getContent(), newLinks));
 	}
 
 	@GetMapping("/employees/detailed")