Manejo De Sesiones En Java

5.2. Creación y recuperación de Sesiones – Carrito de compra.
public class Item {
private String itemCode;
private String itemDesc;
private String itemSummary;
private double itemPrice;

public String getItemCode(){
return itemCode;
}

public String getItemDesc(){
return itemDesc;
}

public StringgetItemSummary(){
return itemSummary;
}

public double getItemPrice(){
return itemPrice;
}

public void setItemCode(String itemCode){
this.itemCode = itemCode;
}

public void setItemDesc(String itemDesc){
this.itemDesc = itemDesc;
}

public void setItemSummary(String itemSummary){
this.itemSummary =itemSummary;
}

public void setItemPrice(double itemPrice){
this.itemPrice = itemPrice;
}
}

Fig. 17. Item.java – JavaBean.

A continuación observaremos la clase que permite gestionar los productos almacenados en la tabla Items.

public class ItemManager {
public Enumeration getItemList() {
try {
Connection con = DBManager.getConnection();Statement st = con.createStatement();
ResultSet rs = st.executeQuery("Select * from itemtable");
Vector itemList = new Vector();
while (rs.next()) {
Item myItem = new Item();
myItem.setItemCode(rs.getString("itemcode"));
myItem.setItemDesc(rs.getString("itemdesc"));myItem.setItemSummary(rs.getString("summary"));
myItem.setItemPrice(rs.getDouble("itemprice"));
itemList.add(myItem);
}
rs.close();
st.close();
con.close();
return itemList.elements();
} catch(Exception e){
e.printStackTrace();
}
return null;
}

public ItemgetItemDetails(String itemCode) {
try {
Connection con = DBManager.getConnection();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("Select * from itemtable where itemcode = '" + itemCode + "'");
if (rs.next()) {
Item myItem = new Item();myItem.setItemCode(rs.getString("itemcode"));
myItem.setItemDesc(rs.getString("itemdesc"));
myItem.setItemSummary(rs.getString("summary"));
myItem.setItemPrice(rs.getDouble("itemprice"));
return myItem;
}
} catch (Exception e){
e.printStackTrace();
}
return null;
}



Fig. 18. ItemManager.java(Parte I).

public Enumeration getSelectedItems(String itemCodes){
try {
Connection con = DBManager.getConnection();
Statement st = con.createStatement();
ResultSet rs = st.executeQuery("Select * from itemtable where itemcode in (" + itemCodes + ")");
Vector itemList = new Vector();
String last = null;while (rs.next()){
Item myItem = new Item();
myItem.setItemCode(rs.getString("itemcode"));
myItem.setItemDesc(rs.getString("itemdesc"));
myItem.setItemSummary(rs.getString("summary"));
myItem.setItemPrice(rs.getDouble("itemprice"));
itemList.add(myItem);
}return itemList.elements();
} catch(Exception e) {
e.printStackTrace();
}
return null;
}
}


Fig. 19. ItemManager.java (Parte II).

A continuación observamos la clase encargada de obtener las conexiones a la base de datos directamente desde el servidor Glassfish.
public class DBManager {
public DBManager() {
}

public static...