import java.io.IOException;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.select.Elements;

public class XML {

    Database database = new Database();

    public void searchAuctions(String searchQuery) throws IOException {

        String serviceAPI = "www.url.com?par=" + searchQuery;

        Document xmlResponse = Jsoup.connect(serviceAPI).get();

        Elements items = xmlResponse.select("item");

        try {

            String fields[] = database.getFields("databaseName", "tableName");
            String values[] = new String[fields.length];
            values[0] = null;

            for (int i = 0; i < items.size(); i++) {
                Elements product = items.eq(i);
                for(int j = 1; j < fields.length; j++) {
                    values[j] = product.select(fields[j]).text();
                }
                boolean isInsert = database.insert("databaseName", "tableName", fields, values);
                if(!isInsert) {
                    System.out.println("Failed to add entry.");
                }
            }

        } catch (Exception ex) {
            ex.printStackTrace(System.out);
            System.exit(1);
        }

    }
}

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class Database {

        private static String dbUsername = "username";
        private static String dbPassword = "password";

        private static String databaseAPI = "jdbc:mysql://localhost:3306/databaseName";
        private static Connection connection;
        private static Statement command;

        /** Gets all table fields from specified database/table. */
        public String[] getFields(String database, String table) {

            List<String> fieldList = new ArrayList<String>();

            try {
                connection = DriverManager.getConnection(databaseAPI, dbUsername, dbPassword);
                command = connection.createStatement();
                ResultSet result = command.executeQuery("SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_NAME='" + table + "'");

                while(result.next()) {
                    fieldList.add(result.getString(1));
                }
            } catch (Exception ex) {
                ex.printStackTrace(System.out);
            }

            String[] tableFields = new String[fieldList.size()];
            for(int i = 0; i < fieldList.size(); ++i) {
                    tableFields[i] = fieldList.get(i);
            }

            return tableFields;

        }

        /** Inserts data into a specified database/table. Used to create new entries. */
        public boolean insert(String database, String table, String[] fields, String[] values) {

            if(fields.length != values.length) {
                return false;
            }

            String separatedFields = "";
            String statementParameters = "";

            for(int i = 0; i < fields.length; ++i) {
                if(i != fields.length - 1) {
                    separatedFields = separatedFields.concat(fields[i] + ",");
                    statementParameters = statementParameters.concat("?,");
                } else {
                    separatedFields = separatedFields.concat(fields[i]);
                    statementParameters = statementParameters.concat("?");
                }
            }

            try {

                connection = DriverManager.getConnection(databaseAPI, dbUsername, dbPassword);
                PreparedStatement sqlStatement = connection.prepareStatement("Insert INTO " + database + "." + table + " (" + separatedFields + ") VALUES (" + statementParameters + ")");


                for(int i = 0; i < values.length; ++i) {
                    sqlStatement.setString(i + 1, values[i]);
                }

                sqlStatement.execute();

            } catch (Exception ex) {
                System.out.println(ex);
                return false;
            }
            return true;
        }
}