diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/AllMetalakeDetails.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/AllMetalakeDetails.java
index 07d61dcaa7c..b76138cb5c9 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/AllMetalakeDetails.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/AllMetalakeDetails.java
@@ -55,6 +55,6 @@ public void handle() {
 
     String all = Joiner.on(System.lineSeparator()).join(metalakeDetails);
 
-    System.out.print(all.toString());
+    System.out.print(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/GroupDetails.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/GroupDetails.java
index 7217d5ad3bd..58188c38a3f 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/GroupDetails.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/GroupDetails.java
@@ -62,6 +62,6 @@ public void handle() {
 
     String all = roles.isEmpty() ? "The group has no roles." : String.join(",", roles);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListAllTags.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListAllTags.java
index cded12808d9..e3bd42ae04c 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListAllTags.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListAllTags.java
@@ -55,6 +55,6 @@ public void handle() {
 
     String all = tags.length == 0 ? "No tags exist." : String.join(",", tags);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListColumns.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListColumns.java
index f3e8e0125cf..e1d8eac2086 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListColumns.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListColumns.java
@@ -94,6 +94,6 @@ public void handle() {
               + System.lineSeparator());
     }
 
-    System.out.print(all.toString());
+    System.out.print(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListEntityTags.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListEntityTags.java
index a1c316fbdf2..c0dc501732e 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListEntityTags.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListEntityTags.java
@@ -93,6 +93,6 @@ public void handle() {
 
     String all = String.join(",", tags);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListFilesets.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListFilesets.java
index d00ba3e6ba5..cb46b7953c3 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListFilesets.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListFilesets.java
@@ -73,6 +73,6 @@ public void handle() {
 
     String all = filesets.length == 0 ? "No filesets exist." : Joiner.on(",").join(filesets);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListGroups.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListGroups.java
index a517b4daed8..844b8e21d09 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListGroups.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListGroups.java
@@ -55,6 +55,6 @@ public void handle() {
 
     String all = groups.length == 0 ? "No groups exist." : String.join(",", groups);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListProperties.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListProperties.java
index 56c8fb8ba78..a7d08ba36e2 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListProperties.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListProperties.java
@@ -51,6 +51,6 @@ public void printProperties(Map<String, String> properties) {
       all.append(property.getKey() + "," + property.getValue() + System.lineSeparator());
     }
 
-    System.out.print(all.toString());
+    System.out.print(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListRoles.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListRoles.java
index 2ecb35bd093..760fe21e3bc 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListRoles.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListRoles.java
@@ -55,6 +55,6 @@ public void handle() {
 
     String all = roles.length == 0 ? "No roles exist." : String.join(",", roles);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListSchema.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListSchema.java
index 110a6477a62..695f44d42d7 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListSchema.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListSchema.java
@@ -62,6 +62,6 @@ public void handle() {
 
     String all = schemas.length == 0 ? "No schemas exist." : Joiner.on(",").join(schemas);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListTables.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListTables.java
index 41a71e87c00..515fb28678c 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListTables.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListTables.java
@@ -66,6 +66,6 @@ public void handle() {
             ? "No tables exist."
             : Joiner.on(System.lineSeparator()).join(tableNames);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListUsers.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListUsers.java
index a70176dcfcb..3df4b7ca6bc 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListUsers.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListUsers.java
@@ -53,8 +53,8 @@ public void handle() {
       exitWithError(exp.getMessage());
     }
 
-    String all = String.join(",", users);
+    String all = users.length == 0 ? "No users exist." : String.join(",", users);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UntagEntity.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UntagEntity.java
index 3503d5eb7bf..e82d0da470a 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UntagEntity.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UntagEntity.java
@@ -19,7 +19,6 @@
 
 package org.apache.gravitino.cli.commands;
 
-import com.google.common.base.Joiner;
 import org.apache.gravitino.Catalog;
 import org.apache.gravitino.NameIdentifier;
 import org.apache.gravitino.Schema;
@@ -33,7 +32,6 @@
 import org.apache.gravitino.rel.Table;
 
 public class UntagEntity extends Command {
-  public static final Joiner COMMA_JOINER = Joiner.on(", ").skipNulls();
   protected final String metalake;
   protected final FullName name;
   protected final String[] tags;
diff --git a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UserDetails.java b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UserDetails.java
index e37f8e6f139..d89597d1698 100644
--- a/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UserDetails.java
+++ b/clients/cli/src/main/java/org/apache/gravitino/cli/commands/UserDetails.java
@@ -62,6 +62,6 @@ public void handle() {
 
     String all = roles.isEmpty() ? "The user has no roles." : String.join(",", roles);
 
-    System.out.println(all.toString());
+    System.out.println(all);
   }
 }