cache ResultSet metadata in getMetaDataMapByMessageId to reduce per-row metadata lookups (#282)

* cache ResultSet metadata in getMetaDataMapByMessageId to reduce per-row metadata lookups

Cache ResultSetMetaData (column count, types, and names) before iterating rows so getColumnType/getColumnName are not called for every row. Adjust column indexing and decryption logging to use the cached metadata. This reduces repeated metadata calls and improves performance when reading connector metadata from the database.

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

* Remove comments

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

* Cache ResultSet metadata before iterating rows to avoid per-row lookups

Cache ResultSetMetaData (column count, types, and names) up front instead of calling getColumnType/getColumnName for every row. This reduces repeated metadata lookups and improves performance when reading metadata rows from the database.

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

* Whoops

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

* Unnecessary comments

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

* Cache ResultSet metadata and use 1-based indexing to avoid per-row metadata lookups

Cache ResultSetMetaData (column count, types, and names) before iterating rows and switch to 1-based arrays/loops so resultSet getters can be called directly with the column index. This prevents repeated getColumnType/getColumnName calls for every row and reduces per-row metadata lookups when building connector metadata maps.

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

---------

Signed-off-by: Nico Piel <nico.piel@hotmail.de>

Author: NicoPiel

donkey/src/main/java/com/mirth/connect/donkey/server/data/jdbc/JdbcDao.java

@@ -2935,6 +2935,15 @@ private Map<Long, Map<Integer, Map<String, Object>>> getMetaDataMaps(String chan
             statement = connection.prepareStatement(querySource.getQuery("getMetaDataMapByMessageId", values));
             resultSet = statement.executeQuery();
 
+            ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
+            int columnCount = resultSetMetaData.getColumnCount();
+            MetaDataColumnType[] columnTypes = new MetaDataColumnType[columnCount + 1];
+            String[] columnNames = new String[columnCount + 1];
+            for (int i = 1; i <= columnCount; i++) {
+                columnTypes[i] = MetaDataColumnType.fromSqlType(resultSetMetaData.getColumnType(i));
+                columnNames[i] = resultSetMetaData.getColumnName(i).toUpperCase();
+            }
+
             while (resultSet.next()) {
                 Long messageId = resultSet.getLong("message_id");
                 Integer metaDataId = resultSet.getInt("metadata_id");
@@ -2951,28 +2960,24 @@ private Map<Long, Map<Integer, Map<String, Object>>> getMetaDataMaps(String chan
                     connectorMetaDataMap.put(metaDataId, metaDataMap);
                 }
 
-                ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
-                int columnCount = resultSetMetaData.getColumnCount();
-
                 for (int i = 1; i <= columnCount; i++) {
-                    MetaDataColumnType metaDataColumnType = MetaDataColumnType.fromSqlType(resultSetMetaData.getColumnType(i));
                     Object value = null;
 
-                    switch (metaDataColumnType) {//@formatter:off
+                    switch (columnTypes[i]) {//@formatter:off
                         case STRING:
                             value = resultSet.getString(i);
                             if (encryptor != null && StringUtils.startsWith((String) value, Encryptor.HEADER_INDICATOR)) {
                                 try {
                                     value = encryptor.decrypt((String) value);
                                 } catch (Exception e) {
-                                    logger.debug("Unable to decrypt custom metadata column " + resultSetMetaData.getColumnName(i).toUpperCase() + " for channel " + channelId + ", messsage " + messageId + "-" + metaDataId, e);
+                                    logger.debug("Unable to decrypt custom metadata column " + columnNames[i] + " for channel " + channelId + ", messsage " + messageId + "-" + metaDataId, e);
                                 }
                             }
                             break;
                         case NUMBER: value = resultSet.getBigDecimal(i); break;
                         case BOOLEAN: value = resultSet.getBoolean(i); break;
                         case TIMESTAMP:
-                            
+
                             Timestamp timestamp = resultSet.getTimestamp(i);
                             if (timestamp != null) {
                                 value = Calendar.getInstance();
@@ -2983,7 +2988,7 @@ private Map<Long, Map<Integer, Map<String, Object>>> getMetaDataMaps(String chan
                         default: throw new Exception("Unrecognized MetaDataColumnType");
                     } //@formatter:on
 
-                    metaDataMap.put(resultSetMetaData.getColumnName(i).toUpperCase(), value);
+                    metaDataMap.put(columnNames[i], value);
                 }
             }