DBItem.java

package beans;

import java.sql.*;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author elcer
 */
public class DBItem {
    private String driver = "com.mysql.jdbc.Driver";
    private String url = "jdbc:mysql://localhost:3306/items";

    private Connection conn = null;

    public DBItem() { //el constructor crea y abre la conexion
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, "usuario", "password");
            if (conn != null)
                System.out.println("Conexion efectuada con exito");
        } catch (ClassNotFoundException | SQLException ex) {
            Logger.getLogger
                (DBItem.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public LinkedList<Item> getItems(String tipo) {
        LinkedList<Item> itemsTipo = new LinkedList<>();
        if (conn != null) {
            try (Statement st = conn.createStatement()) {
                String sqls = "SELECT * from items WHERE tipo='" + tipo + "'";
                try (ResultSet rs = st.executeQuery(sqls)) {
                    while (rs.next()) {
                        String nombre = rs.getString("nombre");
                        Item item = new Item(nombre, tipo);
                        itemTipo.add(item);
                    }
                }
            } catch (SQLException ex) {
                Logger.getLogger(DBItem.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        return itemsTipo;
    }

    public void closeDB() {
        try {
            conn.close();
        } catch (SQLException ex) {
            Logger.getLogger(DBItem.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
}