Refactor error handling and improve output messages in CLI commands

clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListColumns.java

@@ -82,7 +82,7 @@ public void handle() {
               + " "
               + Joiner.on(".").join(metalake, catalog, schema, table));
     } catch (Exception exp) {
-      exitWithError("An error occurred while retrieving column details: " + exp.getMessage());
+      printResults("An error occurred while retrieving column details: " + exp.getMessage());
     }
   }
 }

clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListTables.java

@@ -47,15 +47,16 @@ public ListTables(CommandContext context, String metalake, String catalog, Strin
   /** List the names of all tables in a schema. */
   @Override
   public void handle() {
-    try {
+
       Namespace name = Namespace.of(schema);
       NameIdentifier[] tables = tableCatalog().listTables(name);
 
       if (tables == null || tables.length == 0) {
         printInformation("No tables exist.");
         return;
       }
-
+
+      try {
       Table[] gTables = new Table[tables.length];
       for (int i = 0; i < tables.length; i++) {
         String tableName = tables[i].name();

clients/cli/src/main/java/org/apache/gravitino/cli/commands/ListTagProperties.java

@@ -59,7 +59,7 @@ public void handle() {
     } catch (NoSuchTagException err) {
       exitWithError(ErrorMessages.UNKNOWN_TAG);
     } catch (Exception exp) {
-      exitWithError("An unexpected error occurred: " + exp.getMessage());
+      exitWithError(exp.getMessage());
     }
 
     if (gTag == null) {

clients/cli/src/main/java/org/apache/gravitino/cli/commands/ModelDetails.java

@@ -78,7 +78,7 @@ public void handle() {
     } catch (NoSuchModelException err) {
       exitWithError(ErrorMessages.UNKNOWN_MODEL);
     } catch (Exception err) {
-      exitWithError("An unexpected error occurred: " + err.getMessage());
+      exitWithError(err.getMessage());
     }
 
     if (gModel == null) {

clients/cli/src/main/java/org/apache/gravitino/cli/commands/SchemaAudit.java

@@ -70,7 +70,6 @@ public void handle() {
 
     if (result == null) {
       exitWithError("Failed to retrieve schema details.");
-      return;
     }
 
     displayAuditInfo(result.auditInfo());

clients/cli/src/main/java/org/apache/gravitino/cli/commands/UserDetails.java

@@ -51,18 +51,18 @@ public void handle() {
 
     try (GravitinoClient client = buildClient(metalake)) {
       roles = client.getUser(user).roles();
-    } catch (NoSuchMetalakeException e) {
+    } catch (NoSuchMetalakeException err) {
       exitWithError(ErrorMessages.UNKNOWN_METALAKE);
-    } catch (NoSuchUserException e) {
+    } catch (NoSuchUserException err) {
       exitWithError(ErrorMessages.UNKNOWN_USER);
-    } catch (Exception e) {
-      exitWithError(e.getMessage());
+    } catch (Exception err) {
+      exitWithError(err.getMessage());
     }
 
     if (roles == null || roles.isEmpty()) {
       printInformation("The user has no assigned roles.");
     } else {
-      printResults("User Roles: " + String.join(", ", roles));
+      printResults(String.join(",", roles));
     }
   }
 }