CS 351: Design of Large Programs
                --------------------------------

               Assignment # 4, Due Date  04/19/02
               ----------------------------------


The Extended Markup Language (XML) is a facility that enables communities
of users (for example business, pharmaceutical, etc.) to define their
own tags for inclusion in documents to be exchanged among them.
As in HTML, tags delineate the start and end of elements in a document.
Unlike HTML, however, end tags are mandatory and element/attribute names
are case-sensitive. The correct sequencing, nesting, number of
successive occurences of elements (zero, one or more) and attributes
are specified in a Document Type Definition (DTD). (There is a far more
expressive way of specifying the contents of a document using W3C's
XML Schema Standard but for this assignment we use the DTD.)
An example DTD for purchase orders and a corresponding instance document
is included at the end of this assignment.

The Big Picture
---------------

A head office receives an XML document of purchase orders from a sales
office every few days. The document should be validated and then saved.
Received orders are maintained (without change of format for simplicity)
in files named by month, i.e., all orders placed in the month of
April 2002 are stored in file po02-04 as an XML document.

In addition, XML documents for the following purposes should be created.

(i) The marketing department wishes to receive an XML file containing 
    names of all customers who have shopped within a given period.
    In addition, the total volume of purchases made by each customer
    during that period should be included. The entries should appear
    in decreasing order of total purchase volume.
    (The marketing department needs this information so they can target
    customers for promoting a new product.) The DTD for this document
    appears below.
   
    <?xml version="1.0" encoding="UTF-8" standalone="yes" ?>

    <!DOCTYPE customers [
     <!ELEMENT customers (customer+ ) >
      <!ELEMENT customer (cust_name, address, totalpurchase ) >
      <!ATTLIST customer cust_id CDATA #REQUIRED>
       <!ELEMENT cust_name (#PCDATA) >
       <!ELEMENT address (block, city, zip, phone+, fax*, mobile?) >
       <!ELEMENT totalpurchase (#PCDATA) >
         <!ELEMENT block (#PCDATA) >
         <!ELEMENT city (#PCDATA) >
         <!ELEMENT zip (#PCDATA) >
         <!ELEMENT phone (#PCDATA) >
         <!ELEMENT fax (#PCDATA) >
         <!ELEMENT mobile (#PCDATA) >

     ]>


(ii) This part is for extra credit only.
     The suppliers to the store wish to receive the number of items of
     each product purchased (without regard to who has purchased what.)
     This information should be communicated every few days.
     (This information will be forwarded to the manufacturers so they
     can plan how much of what to manufacture in the next production
     cycle.) This too should be contained in an XML document whose
     type is defined in the DTD to be given in class.


This semester, we will experiment with the Java Architecture for XML
Binding (JAXB) which provides an API and tool that allows automatic
two-way mapping between XML documents and Java objects. Please read
the primer, sample code and Mike Dolan's handout before you proceed.
The main ideas/steps are summarized below:

(1) We create a minimal binding schema by saving the following in file 
    orders.xjs:  

    <xml-java-binding-schema>
    <element name="orders" type="class" root="true">
    </xml-java-binding-schema>

(2) Invoke the schema compiler with the command xjc and two command line
    parameters --  the DTD and the binding schema.
    This creates a Java class for each "complex" element in the DTD.
    A complex element is one that contains other elements or that has
    an attribute. Each class has accessor and mutator methods for 
    handling its data members (which correspond to the sub-elements
    and attributes of the element.) Sub-elements that may occur more than
    once are mapped to a List of objects of type corresponding to that
    sublement.
    Each class also contains methods for unmarshalling an XML document
    (populating lists in instances of the above created classes using
    data in the XML document), marshalling (reverse of unmarshalling)
    and validating an object tree.

    For the orders.dtd, the schema compiler should generate a total of
    nine classes 
		Orders.java	Order.java	Customer.java
		Items.java	Item.java	Payment.java
		Address.java	Cash.java	Credit.java

    Note the relation between element and class names. Inspect the
    source files of these classes and note the convention for naming
    of the accessor and mutator methods since you will need to use them.


(3) Now we need to write the Java application program. 

    Part 1
    ------
    Your program should read a total of 10 XML files containing purchase
    orders. Each file will typically contain orders placed within a week
    (but the week itself may straddle two successive months.) 
    Orders read should be saved in the appropriate file, i.e. if an
    input file has weekly orders some of which were placed in end-april02
    and some in early-may02, then the former should be saved in file
    po02-04 and the latter in file po02-05.
    For simplicity assume that the orders within a file are in temporal
    order (increasing order of date.) 

    Part 2
    ------
    Upon completion of Part 1, your program should display:

    All 10 XML files read, unmarshalled and saved.
    Enter period of interest to the Marketing Dept.:

    At this point the user is expected to enter two dates  in the format
    yy-mm-dd

    02-01-16 02-02-15

    This means that the total volume of purchases made by each customer 
    during that period (between Jan 16, 2002 and Feb 15, 2002 inclusive)
    should be computed and saved in file "mark".
    The root element for this document is customers and its DTD appears 
    above.

    Part 3 (Extra Credit Part)  Details later. 
    ------







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The POs that comprise the document your program will receive are
defined by the DTD (Document Type Definition) below.


<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>

<!DOCTYPE orders [

<!ELEMENT orders (order+) >
<!ELEMENT order (date, customer, items, total, payment ) >
<!ATTLIST order order_id CDATA #REQUIRED>
<!ELEMENT customer (cust_name, address ) >
<!ATTLIST customer cust_id CDATA #REQUIRED>
<!ELEMENT address (block, city, zip, phone+, fax*, mobile?) >
<!ELEMENT items (item+ ) >
<!ELEMENT item (item_name, discount?, price, quantity, subtotal ) >
<!ATTLIST item item_id CDATA #REQUIRED>
<!ELEMENT payment ( cash | credit)>
<!ELEMENT cash (amount_paid, change)>  
<!ELEMENT credit (card_type, card_owner, card_number, expiration_date)>
                            

<!ELEMENT date (#PCDATA) >
<!ELEMENT total (#PCDATA) >
<!ELEMENT cust_name (#PCDATA) >
<!ELEMENT block (#PCDATA) >
<!ELEMENT city (#PCDATA) >
<!ELEMENT zip (#PCDATA) >
<!ELEMENT phone (#PCDATA) >
<!ELEMENT fax (#PCDATA) >
<!ELEMENT mobile (#PCDATA) >
<!ELEMENT item_name (#PCDATA) >
<!ELEMENT discount (#PCDATA) >
<!ELEMENT price (#PCDATA) >
<!ELEMENT quantity (#PCDATA) >
<!ELEMENT subtotal (#PCDATA) >
<!ELEMENT type (#PCDATA) >
<!ELEMENT amount_paid (#PCDATA) >
<!ELEMENT change (#PCDATA) >
<!ELEMENT card_type (#PCDATA) >
<!ELEMENT card_owner (#PCDATA) >
<!ELEMENT card_number (#PCDATA) >
<!ELEMENT expiration_date (#PCDATA) >

]>

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A sample XML document of POs is shown below.

<orders>
   <order order_id="789">
     <date>10/22/2001</date>
     <customer cust_id="5432">
	 <cust_name>John</cust_name>
	 <address>
            <block>1010 Main</block>
	    <city>Albuquerque</city>
	    <zip>87131</zip>
	    <phone>1234567</phone>
       	    <fax>2347654</fax>
	 </address>
     </customer>	 
     <items>
	    <item item_id="472">
		<item_name>shoes</item_name>
		<price>5.00</price>
		<quantity>1</quantity>
		<subtotal>5.00</subtotal>
	    </item>
	    <item item_id="290">
		<item_name>sugar</item_name>
                <discount>15</discount>
		<price>2.00</price>
		<quantity>2</quantity>
		<subtotal>4.00</subtotal>
	    </item>
      </items>     
      <total>9.00</total>
      <payment>
	     <cash>
	        <amount_paid>10.00</amount_paid>
	        <change>1.00</change>
	     </cash>
      </payment>
   </order>

   <order order_id="799">
     <date>10/24/2001</date>
     <customer cust_id="2411">
	 <cust_name>Mary</cust_name>
	 <address>
            <block>2643 Bronze</block>
	    <city>New York</city>
	    <zip>88131</zip>
	    <phone>2345678</phone>
	    <phone>5678234</phone>
       	    <fax>4765411</fax>
	 </address>
     </customer>
     <items>
	    <item item_id="307">
		<item_name>ink</item_name>
		<price>1.00</price>
		<quantity>5</quantity>
		<subtotal>5.00</subtotal>
	    </item>
     </items>
     <total>5.00</total>
     <payment>
            <credit>
               <card_type>VISA</card_type>
               <card_owner>Mary</card_owner>
               <card_number>1234567890</card_number>
               <expiration_date>07/03</expiration_date>
            </credit>
     </payment>
   </order> 
								   
   <order order_id="889">
     <date>10/24/2001</date>
     <customer cust_id="3790">
	 <cust_name>Steve</cust_name>
	 <address>
            <block>7432 Silver</block>
	    <city>Greenbelt</city>
	    <zip>89131</zip>
	    <phone>2345678</phone>
            <mobile>4320659</mobile>
	 </address>
     </customer>
     <items>
	    <item item_id="687">
		<item_name>tooth paste</item_name>
		<price>2.50</price>
		<quantity>2</quantity>
		<subtotal>5.00</subtotal>
	    </item>
	    <item item_id="285">
		<item_name>tooth brush</item_name>
		<price>1.00</price>
		<quantity>2</quantity>
		<subtotal>2.00</subtotal>
	    </item>
     </items>
     <total>7.00</total>
     <payment>
	     <cash>
	        <amount_paid>10.00</amount_paid>
	        <change>3.00</change>
	     </cash>
     </payment>
     </order>


   <order order_id="989">
     <date>10/25/2001</date>
     <customer cust_id="1834">
	 <cust_name>John</cust_name>
	 <address>
            <block>5103 Gold</block>
	    <city>Round Rock</city>
	    <zip>90131</zip>
	    <phone>1234567</phone>
	 </address>
     </customer>
     <items>
	    <item item_id="554">
		<item_name>TV set</item_name>
                <discount>10</discount>
		<price>150.00</price>
		<quantity>1</quantity>
		<subtotal>150.00</subtotal>
	    </item>
     </items>	
          <total>150.00</total>
          <payment>
 	     <cash>
	        <amount_paid>150.00</amount_paid>
	        <change>0.00</change>
 	     </cash>
	  </payment>
    </order>

</orders>

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