From 07e590ad26042b002e89e6b30a86d222436d50de Mon Sep 17 00:00:00 2001
From: fwang12 <fwang12@ebay.com>
Date: Sun, 28 May 2023 12:46:09 +0800
Subject: [PATCH] [KYUUBI #4893] [MINOR] Prevent null collection for rest dto

### _Why are the changes needed?_

As title.

### _How was this patch tested?_
- [ ] Add some test cases that check the changes thoroughly including negative and positive cases if possible

- [ ] Add screenshots for manual tests if appropriate

- [x] [Run test](https://kyuubi.readthedocs.io/en/master/develop_tools/testing.html#running-tests) locally before make a pull request

Closes #4893 from turboFei/minor_dto.

Closes #4893

aeb5a25a9 [fwang12] prevent null:

Authored-by: fwang12 <fwang12@ebay.com>
Signed-off-by: fwang12 <fwang12@ebay.com>
---
 .../org/apache/kyuubi/client/api/v1/dto/OperationData.java    | 4 ++++
 .../java/org/apache/kyuubi/client/api/v1/dto/ServerData.java  | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/OperationData.java b/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/OperationData.java
index 8b1f7656e..70c2dd3f3 100644
--- a/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/OperationData.java
+++ b/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/OperationData.java
@@ -17,6 +17,7 @@
 
 package org.apache.kyuubi.client.api.v1.dto;
 
+import java.util.Collections;
 import java.util.Map;
 import java.util.Objects;
 import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
@@ -154,6 +155,9 @@ public class OperationData {
   }
 
   public Map<String, String> getMetrics() {
+    if (null == metrics) {
+      return Collections.emptyMap();
+    }
     return metrics;
   }
 
diff --git a/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/ServerData.java b/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/ServerData.java
index 6fe036162..7b68763d2 100644
--- a/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/ServerData.java
+++ b/kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/ServerData.java
@@ -17,6 +17,7 @@
 
 package org.apache.kyuubi.client.api.v1.dto;
 
+import java.util.Collections;
 import java.util.Map;
 import java.util.Objects;
 
@@ -94,6 +95,9 @@ public class ServerData {
   }
 
   public Map<String, String> getAttributes() {
+    if (null == attributes) {
+      return Collections.emptyMap();
+    }
     return attributes;
   }