fix un-correct tips for create topic error when namespace not exist (a…

…pache#9223)

Fixes apache#9220

Motivation
fix un-correct tips for create topic error when namespace not exist

pulsar-broker/src/main/java/org/apache/pulsar/broker/admin/AdminResource.java

@@ -321,6 +321,9 @@ protected void validateGlobalNamespaceOwnership(String property, String namespac
         } catch (IllegalArgumentException e) {
             throw new RestException(Status.PRECONDITION_FAILED, "Tenant name or namespace is not valid");
         } catch (RestException re) {
+            if (re.getResponse().getStatus() == Status.NOT_FOUND.getStatusCode()) {
+                throw new RestException(Status.NOT_FOUND, "Namespace not found");
+            }
             throw new RestException(Status.PRECONDITION_FAILED, "Namespace does not have any clusters configured");
         } catch (Exception e) {
             log.warn("Failed to validate global cluster configuration : ns={}  emsg={}", namespace, e.getMessage());

pulsar-broker/src/test/java/org/apache/pulsar/broker/admin/AdminApiTest.java

@@ -2180,6 +2180,18 @@ public void testPersistentTopicExpireMessageOnParitionTopic() throws Exception {
 
     }
 
+    @Test
+    public void testNamespaceNotExist() throws Exception {
+        final String nonPartitionedtopic = "persistent://prop-xyz/no-exist/non-partitioned-topic";
+        try {
+            admin.topics().createNonPartitionedTopic(nonPartitionedtopic);
+            fail("should falied for namespaces not exist");
+        } catch (Exception e) {
+            assertTrue(e instanceof NotFoundException);
+            assertTrue(e.getMessage().equals("Namespace not found"));
+        }
+    }
+
     @Test
     public void testPersistentTopicCreation() throws Exception {
         final String nonPartitionedtopic = "persistent://prop-xyz/ns1/non-partitioned-topic";