[SPARK-46393][SQL][FOLLOWUP] Classify exceptions in JDBCTableCatalog.…

…loadTable

### What changes were proposed in this pull request?

This is a followup of #44335 , which missed to handle `loadTable`

### Why are the changes needed?

better error message

### Does this PR introduce _any_ user-facing change?

no

### How was this patch tested?

existing test

### Was this patch authored or co-authored using generative AI tooling?

no

Closes #46905 from cloud-fan/jdbc.

Authored-by: Wenchen Fan <wenchen@databricks.com>
Signed-off-by: Kent Yao <yao@apache.org>

common/utils/src/main/resources/error/error-conditions.json

@@ -1255,6 +1255,11 @@
           "List namespaces."
         ]
       },
+      "LOAD_TABLE" : {
+        "message" : [
+          "Load the table <tableName>."
+        ]
+      },
       "NAMESPACE_EXISTS" : {
         "message" : [
           "Check that the namespace <namespace> exists."

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/v2/jdbc/JDBCTableCatalog.scala

@@ -131,13 +131,16 @@ class JDBCTableCatalog extends TableCatalog
     checkNamespace(ident.namespace())
     val optionsWithTableName = new JDBCOptions(
       options.parameters + (JDBCOptions.JDBC_TABLE_NAME -> getTableName(ident)))
-    try {
+    JdbcUtils.classifyException(
+      errorClass = "FAILED_JDBC.LOAD_TABLE",
+      messageParameters = Map(
+        "url" -> options.getRedactUrl(),
+        "tableName" -> toSQLId(ident)),
+      dialect,
+      description = s"Failed to load table: $ident"
+    ) {
       val schema = JDBCRDD.resolveTable(optionsWithTableName)
       JDBCTable(ident, schema, optionsWithTableName)
-    } catch {
-      case e: SQLException =>
-        logWarning("Failed to load table", e)
-        throw QueryCompilationErrors.noSuchTableError(ident)
     }
   }