Apakah Cara Paling Cekap untuk Menukar ResultSet kepada JSON di Java?

Penukaran ResultSet kepada JSON yang Paling Cekap?

Kod berikut menggunakan tatasusunan dan objek JSON untuk menukar set hasil kepada rentetan JSON:

import org.json.JSONArray;
import org.json.JSONObject;
import org.json.JSONException;

import java.sql.SQLException;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;

public class ResultSetConverter {
  public static JSONArray convert( ResultSet rs )
    throws SQLException, JSONException
  {
    JSONArray json = new JSONArray();
    ResultSetMetaData rsmd = rs.getMetaData();

    while(rs.next()) {
      int numColumns = rsmd.getColumnCount();
      JSONObject obj = new JSONObject();

      for (int i=1; i<numColumns+1; i++) {
        String column_name = rsmd.getColumnName(i);

        // Determine the SQL data type of the column
        switch(rsmd.getColumnType(i)) {
          case java.sql.Types.ARRAY:
            obj.put(column_name, rs.getArray(column_name));
            break;
          case java.sql.Types.BIGINT:
            obj.put(column_name, rs.getInt(column_name));
            break;
          case java.sql.Types.BOOLEAN:
            obj.put(column_name, rs.getBoolean(column_name));
            break;
          case java.sql.Types.BLOB:
            obj.put(column_name, rs.getBlob(column_name));
            break;
          case java.sql.Types.DOUBLE:
            obj.put(column_name, rs.getDouble(column_name));
            break;
          case java.sql.Types.FLOAT:
            obj.put(column_name, rs.getFloat(column_name));
            break;
          case java.sql.Types.INTEGER:
            obj.put(column_name, rs.getInt(column_name));
            break;
          case java.sql.Types.NVARCHAR:
            obj.put(column_name, rs.getNString(column_name));
            break;
          case java.sql.Types.VARCHAR:
            obj.put(column_name, rs.getString(column_name));
            break;
          case java.sql.Types.TINYINT:
            obj.put(column_name, rs.getInt(column_name));
            break;
          case java.sql.Types.SMALLINT:
            obj.put(column_name, rs.getInt(column_name));
            break;
          case java.sql.Types.DATE:
            obj.put(column_name, rs.getDate(column_name));
            break;
          case java.sql.Types.TIMESTAMP:
            obj.put(column_name, rs.getTimestamp(column_name));
            break;
          default:
            obj.put(column_name, rs.getObject(column_name));
            break;
        }
      }

      json.put(obj);
    }

    return json;
  }
}

Alternatif Penyelesaian:

Pendekatan alternatif, yang mungkin lebih ringkas dan lebih cekap ingatan, melibatkan penggunaan kaedah getObject() secara langsung:

JSONArray json = new JSONArray();
ResultSetMetaData rsmd = rs.getMetaData();
while(rs.next()) {
  int numColumns = rsmd.getColumnCount();
  JSONObject obj = new JSONObject();
  for (int i=1; i<=numColumns; i++) {
    String column_name = rsmd.getColumnName(i);
    obj.put(column_name, rs.getObject(column_name));
  }
  json.put(obj);
}
return json;

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