1    package xml.cart; 
2     
3    import org.xml.sax.helpers.DefaultHandler; 
4     
5    import java.util.Vector; 
6     
7    import xml.cart.Cart; 
8    import xml.Product; 
9     
10   /** 
11    *   The CartDocumentHandler gets notification in 
12    * the form of a call-back method. These 
13    * call-backs are like the Listener model 
14    * used for event handling. When a new element 
15    * is encountered, for example, that creates 
16    * a call-back. The call-backs are handled 
17    * in the DocumentHandler: 
18    
19    */ 
20   public class CartDocumentHandler 
21           extends DefaultHandler { 
22    
23       private Cart c = new Cart(); 
24       private Vector stringVector = new Vector(); 
25    
26       public Cart getCart() { 
27           return c; 
28       } 
29    
30       /** 
31        *      The Locator  instance must be 
32        * used locally to identify 
33        * the origin of a SAX event. 
34        */ 
35       //public void setDocumentLocator(Locator l) { 
36       //} 
37    
38       // public void startDocument() 
39       //     throws SAXException { 
40       // } 
41    
42       // public void endDocument() 
43       //    throws SAXException { 
44       //} 
45    
46       /** The AttributeList is not 
47        * going to have any attributes 
48        * in it for our example (i.e. 
49        * <book isbn=10> provides an 
50        * attribute of isbn whose value is 10). 
51        */ 
52       public void startElement() { 
53       } 
54    
55       /** 
56        * When we get the </Product> tag, then 
57        * we want to invoke 
58        * addProduct otherwise, just return: 
59        */ 
60       public void endElement(String name) { 
61           if (!name.equals("Product")) return; 
62           addProduct(); 
63       } 
64    
65       /** 
66        * addProduct will 
67        * make an instance of a 
68        * Product class and add it to the 
69        * Cart instance. It is added by parsing 
70        * the last three strings that 
71        * have been pushed into the StringVector. 
72        */ 
73       public void addProduct() { 
74           String sa[] = new String[stringVector.size()]; 
75           stringVector.copyInto(sa); 
76           if (sa.length < 3) return; 
77    
78           String name = sa[0]; 
79           float price = Float.valueOf(sa[1]).floatValue(); 
80           int productId = Integer.valueOf(sa[2]).intValue(); 
81    
82           Product p 
83                   = new Product(name, price, productId); 
84           c.addProduct(p); 
85           stringVector = new Vector(); 
86       } 
87    
88       /** 
89        * 
90        * when characters are found, we add them to 
91        * the string vector for latter use. 
92        */ 
93       public void characters(char buf [], int offset, int len) { 
94           stringVector.addElement(new String(buf, offset, len)); 
95       } 
96    
97       public void ignorableWhitespace( 
98               char buf [], int offset, int len) { 
99       } 
100   
101      /** 
102       * The processingInstruction is 
103       *  called back when a non XML 
104       * declaration is made. 
105       */ 
106      public void processingInstruction( 
107              String target, 
108              String data) { 
109      } 
110   
111  } 
112