Officially Inaugurating the Catsup Week
"These are the days of miracle and wonder..."
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Officially Inaugurating the Catsup Week
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Catsup Days are finally here.
frilled.cs.indiana.edu%webster inaugurate
in-au-gu-rate \in-'o[0xC7]-g(y)e-,ra^-t\ vt -rat-ed; -rat-ing
[L inauguratus, pp. of inaugurare, lit., to practice augury, fr. in-
+ augurare to augur; fr. the rites connected with augury]
(1606)
1: to induct into an office with suitable ceremonies
2a: to dedicate ceremoniously: observe formally the beginning of
2b: to bring about the beginning of
syn see BEGIN
-- in-au-gu-ra-tor \-,ra^-t-er\ n
frilled.cs.indiana.edu%So we bring about the beginning of this final week with suitable ceremonies, and celebration.
Main administrative announcements for today, and rest of the week are, as follows:
CONTENT SYNDICATION
Couldn't we really simply stop here?No, we really need to get started: it's ten to six (when Mr. K performs his tricks). We can't be late.
Let's start with a portion of a file: interface.html
<html>
<head>
<title>FooBar Public Library: Add Books Interface</title>
<style>
<!--
body { font-family: Arial }
h1 { color: #000080 }
-->
</style>
</head>
<body link="#FFFF00" vlink="#FFFF00" alink="#FFFF00">
<table border="0" width="100%" cellpadding="0" cellspacing="0">
<tr>
<td width="15%" bgcolor="#000080" valign="top" align="center"> </td>
<td width="*" valign="top" align="center">
<h1 align="center"> The Foobar Public Library </h1>
<h3 align="center"><i>- Add Books -</i></h3>
<form method="POST" action="/cgi-bin/foobar/addBook.pl">
<p>
<input type="submit" value="Add This Book" name="AddBook">
<input type="reset" value="Reset Form" name="reset">
<input type="button" value="Cancel" name="cancel">
</p>
</form>
</td>
</tr>
</table>
</body>
</html>Let's add all there is to it and finish it./u/username/apache/apache_1.3.20/htdocs/interface.html
<html>
<head>
<title>FooBar Public Library: Add Books Interface</title>
<style>
<!--
body { font-family: Arial }
h1 { color: #000080 }
-->
</style>
</head>
<body link="#FFFF00" vlink="#FFFF00" alink="#FFFF00">
<table border="0" width="100%" cellpadding="0" cellspacing="0">
<tr>
<td width="15%" bgcolor="#000080" valign="top" align="center">
<b><i><font color="#FFFFFF" size="4">Options</font></i></b>
<p><b><font color="#FFFFFF"><a href="mainMenu.html">Main Menu</a></font></b></p>
<p><b><font color="#FFFFFF"><a href="/cgi-bin/foobar/catalog.pl">Catalog</a></font></b></p>
<p><b><i><font color="#FFFF00">Add Books</font></i></b></p>
<p><b><font color="#FFFFFF"><a href="logout.html">Log Out</a></font></b></p>
</td>
<td width="*" valign="top" align="center">
<h1 align="center"> The Foobar Public Library </h1>
<h3 align="center"><i>- Add Books -</i></h3>
<form method="POST" action="/cgi-bin/foobar/addBook.pl">
<table border="0" cellpadding="5" width="100%">
<tr>
<td width="100%" valign="top" align="center" colspan="2">
Title <input type="text" name="title" size="20">
<hr width="85%" />
</td>
</tr><tr>
<td width="50%" valign="top" align="right">
Author <input type="text" name="author" size="20">
</td> <td width="50%" valign="top" align="left">
Subject <select size="1" name="subject">
<option>Fiction</option>
<option>Biography</option>
<option>Science</option>
<option>Industry</option>
<option>Computers</option>
</select>
</td>
</tr><tr>
<td width="50%" valign="top" align="right">
Publisher <input type="text" name="publisher" size="20">
</td><td width="50%" valign="top" align="left">
ISBN <input type="text" name="isbn" size="20">
</td>
</tr><tr>
<td width="50%" valign="top" align="right">
Price <input type="text" name="price" size="20">
</td><td width="50%" valign="top" align="left">
Pages <input type="text" name="numPages" size="20">
</td>
</tr><tr>
<td width="100%" valign="top" align="center" colspan="2">
Description <textarea rows="3" name="description" cols="45"></textarea>
</td>
</tr>
</table>
<p>
<input type="submit" value="Add This Book" name="AddBook">
<input type="reset" value="Reset Form" name="reset">
<input type="button" value="Cancel" name="cancel">
</p>
</form>
</td>
</tr>
</table>
</body>
</html>addBook.pl Perl script, so we better provide it, quickly.
#!/usr/bin/perl
use CGI;
$query = new CGI;
print $query->header,
$query->start_html,
"Hello, how are you?<p>";
$title = $query->param('title');
$author = $query->param('author') ;
$subject = $query->param('subject');
$publisher = $query->param('publisher');
$isbn = $query->param('isbn');
$price = $query->param('price');
$pages = $query->param('pages');
$description = $query->param('description');
print qq{
You seem to be entering the following book:
<dl>
<dt>Title</dt> <dd> $title<p></dd>
<dt>Author</dt> <dd> $author<p></dd>
<dt>Subject</dt> <dd> $subject<p></dd>
<dt>Publisher</dt> <dd> $publisher<p></dd>
<dt>ISBN</dt> <dd> $isbn<p></dd>
<dt>Price</dt> <dd> $price<p></dd>
<dt>Pages</dt> <dd> $pages<p></dd>
<dt>Description</dt> <dd> $description <p></dd>
</dl>
};
print $query->end_html;Let's decide on these things first:
The format will be very simple. Here's an example:/u/username/foobar/data/dataFile.txt
Let's assume now (for the purpose of this exercise) that colon (title:author:subject:publisher:isbn:price:numPages:description
:) is a character that
we own exclusively. We have bought this character and nobody can use it, except us. So we use it, as we
are now guaranteed to be the only ones to do so, as a delimiter. Total fabrication, but let's agree to it. Here's an example of a real book:
The ISBN will be the key.
- Title
- The Armchair Universe - An Exploration of Computer Worlds
- Author
- A. K. Dewdney
- Subject
- Science
- Publisher
- W. H. Freeman and Company, New York
- ISBN
- 0-7167-1939-8
- Price
- 19.90
- Number of Pages
- 330
- Description
- This is the first collection of A.K.Dewdney's popular "Computer Recreations" columns, drawn from Scientific American magazine between 1984 and 1987. Inspired by Martin Gardner's classic "Mathematical Games" column, which entertained millions of readers for more than 30 years, "Computer Recreations" has quickly become one of the most widely read and anticipated columns in Scientific American. The computer recreations described here range from purely entertaining brainteasers to more practical computer applications of scientific thought. And with Dewdney's lucid programming directions to follow, you can actually sit at your computer and try your hand at them all. Available in paperback and hardcover. Cover image shows Julia set bounding three basins of attraction on a Riemann sphere.
Which brings us to the last question.
The real model behind this file is a table in a RDBMS like MySQL.
By the way, you know (as I hope you remember) that readParse
taught us how we can make characters our own, anyway, so the story about needing
a guarantee for colon is a non-issue, really.
So let's get started.
#!/usr/bin/perl
use CGI;
$query = new CGI;
print $query->header,
$query->start_html,
"Hello, and how are you doing? <p> ";
$title = $query->param('title');
$author = $query->param('author') ;
$subject = $query->param('subject');
$publisher = $query->param('publisher');
$isbn = $query->param('isbn');
$price = $query->param('price');
$numPages = $query->param('numPages');
$description = $query->param('description');
print qq{
You seem to be entering the following book:
<dl>
<dt>Title</dt> <dd> $title<p></dd>
<dt>Author</dt> <dd> $author<p></dd>
<dt>Subject</dt> <dd> $subject<p></dd>
<dt>Publisher</dt> <dd> $publisher<p></dd>
<dt>ISBN</dt> <dd> $isbn<p></dd>
<dt>Price</dt> <dd> $price<p></dd>
<dt>Number of Pages</dt> <dd> $numPages<p></dd>
<dt>Description</dt> <dd> $description <p></dd>
</dl>
};
%library = ();
open (AB, "/u/dgerman/foobar/data/dataFile.txt");
@x = <AB>;
close(AB);
foreach $line (@x) {
@line = split(/:/, $line);
$key = $line[4];
$library{$key} = $line;
}
#add new book
$library{$isbn} = "$title:$author:$subject:$publisher:$isbn:$price:$numPages:$description";
$newline = chr(13);
$library{$isbn} =~ s/[\n\r$newline]/ /g;
$library{$isbn} =~ s/\s/ /g;
open (AB, ">/u/dgerman/foobar/data/dataFile.txt");
foreach $key (sort (keys %library)) {
print AB $library{$key}, "\n";
}
close(AB);
print "The book has been added, thank you. ", $query->end_html; Hello, and how are you doing?There are a few issues that we won't even consider, such as:You seem to be entering the following book:
The book has been added, thank you.
- Title
- In Search of Lake Wobegon
- Author
- Garrison Keillor, Richard Olsenius (Photographer)
- Subject
- Biography
- Publisher
- Viking Press
- ISBN
- 0-6700-3037-6
- Price
- 29.95
- Number of Pages
- 128
- Description
- In the twenty-five years since Garrison Keillor first brought it to life, the rural Minnesota town of Lake Wobegon has become a national treasure. In this lavishly produced photography book, word and image combine to illuminate the real Minnesota town-life, landscapes, and people who inspired its creation. Taking us on a tour of Stearns County, the Minnesota county he deems most "Wobegonic," Keillor meditates on the origins of the place where, as a young writer, he found the inspiration for his fiction and his radio show. As an artful evocation of Keillor's beloved invention, Richard Olsenius's elegantly composed black-and-white photographs of rural Minnesota capture the dignity of his subjects, the beauties of the landscape as well as the enduring values and eccentricities of the communities rooted there.
And now the story.
Long, interesting, involving story about Best Book Buys comes here and touches the audience.
To summarize here are the facts:
Let's review servlets briefly, just so we know what we can count on.
We have this servlet, One:
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class One extends HttpServlet {
public void doGet(HttpServletRequest one,
HttpServletResponse two)
throws ServletException, IOException
{
two.setContentType("text/html");
PrintWriter out = two.getWriter();
out.println("How are you?");
}
} Two:
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class Two extends HttpServlet {
public void doGet(HttpServletRequest one,
HttpServletResponse two)
throws ServletException, IOException
{
String p = one.getParameter("nom");
two.setContentType("text/html");
PrintWriter out = two.getWriter();
out.println("How are you, " + p + "?");
}
} So now let's look at the third one. (Recall the chat applet, if you will, it could be handy.)
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class Three extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
URL getBooksURL = new URL("http",
"burrowww.cs.indiana.edu",
31090,
"/cgi-bin/foobar/catalog.pl");
URL url = new URL(getBooksURL.toExternalForm());
URLConnection con = url.openConnection();
con.setUseCaches(false);
InputStream in = con.getInputStream();
DataInputStream data = new DataInputStream(new BufferedInputStream(in));
String line = data.readLine();
while (line != null) {
out.println(line);
line = data.readLine();
}
out.println("<p> This is the end of the servlet");
}
}
How do we become more systematic, so a computer program can figure it out for us? How do make it such that changes in the structure of data can be effectively absorbed by the program that reads the data? And, is that possible? The answer is: yes, that's what XML was invented for.
So we switch to XML. First we need a report script that transforms the database in XML.
But wait. Let's see some examples before we go too far, so we know what we're talking about.
Important Note:
You will need
This contains an archive of classes used for parsing./u/dgerman/public/xerces.jar
The parser (what's that?) we use is called Xerces.
Were does the name come from?
The Apache Xerces parser is called after the now extinct Xerces Blue Butterfly. Wiped out by urban expansion, the last known specimens were taken in 1941 at the Presidio military base in San Francisco. The butterfly was named after a king. A French entomologist named the butterfly for the Persian King Xerxes, but with the French spelling "Xerces," which was retained.
King Xerxes, son of Darius, ascended to the throne of Persia after his father's death in 486 BC. By 480 BC, the army he assembled had approximately 100,000 to 180,000 men and a fleet of nearly 600 ships, quite a large army by Greek standards and he decided to invade Greece. The plan was for his massive army to cross the Hellespont, and march around the Aegean sea and conquer Greece by land.
Crossing the Hellespont proved to be troublesome to Xerxes and his army. They tried to cross the Hellespont with a bridge of boats, but alas, the sea became rough and the bridge broke apart. When King Xerxes heard of this, he was furious, and gave orders that the sea should receive 300 lashes with whips. The sea did calm down and the second attempt to build a bridge was successful.
This, however, happened a long, long time ago.
Place the xerces.jar file in $TOMCAT_HOME/lib.
Re-start your tomcat.
I use the following for starting and stopping Tomcat:
Also make sure yoursetenv startTomcat $TOMCAT_HOME/bin/startup.sh setenv stopTomcat $TOMCAT_HOME/bin/shutdown.sh
CLASSPATH variable points to the xerces.jar file.
And now let's look at some XML examples.setenv CLASSPATH $TOMCAT_HOME/lib/xerces.jar:$CLASSPATH
Script started on Tue Dec 04 09:18:50 2001
burrowww.cs.indiana.edu% pwd
/nfs/paca/home/user1/dgerman/foobar
burrowww.cs.indiana.edu% ls -l
total 2
drwxr-xr-x 2 dgerman faculty 512 Dec 3 02:25 data
drwxr-xr-x 2 dgerman faculty 512 Dec 4 09:18 parser
burrowww.cs.indiana.edu% ls data
dataFile.txt
burrowww.cs.indiana.edu% cd parser
burrowww.cs.indiana.edu% ls -l
total 7
-rw-r--r-- 1 dgerman faculty 515 Dec 4 07:25 FirstParser.java
-rw-r--r-- 1 dgerman faculty 3693 Dec 4 09:18 IndentingParser.java
-rw-r--r-- 1 dgerman faculty 681 Dec 4 09:17 customer.xml
-rw-r--r-- 1 dgerman faculty 184 Dec 4 09:17 greeting.xml
burrowww.cs.indiana.edu% cat customer.xml
<?xml version="1.0"?>
<document>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
<item> Four </item>
</customer>
<customer>
<item> One </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
<item> Four </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
<item> Four </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
</customer>
</document>
burrowww.cs.indiana.edu% cat greeting.xml
<?xml version="1.0" encoding="UTF-8"?>
<document>
<greeting>
Hello from XML
</greeting>
<message>
Welcome to the wild and woolly world of XML.
</message>
</document>
burrowww.cs.indiana.edu% javac *.java
burrowww.cs.indiana.edu% ls -l
total 13
-rw-r--r-- 1 dgerman faculty 1300 Dec 4 09:19 FirstParser.class
-rw-r--r-- 1 dgerman faculty 515 Dec 4 07:25 FirstParser.java
-rw-r--r-- 1 dgerman faculty 3369 Dec 4 09:19 IndentingParser.class
-rw-r--r-- 1 dgerman faculty 3693 Dec 4 09:18 IndentingParser.java
-rw-r--r-- 1 dgerman faculty 681 Dec 4 09:17 customer.xml
-rw-r--r-- 1 dgerman faculty 184 Dec 4 09:17 greeting.xml
burrowww.cs.indiana.edu% java FirstParser greeting.xml
greeting.xml has 0 <customer> elements.
burrowww.cs.indiana.edu% java FirstParser customer.xml
customer.xml has 6 <customer> elements.
burrowww.cs.indiana.edu% java IndentingParser customer.xml
<?xml version="1.0" encoding="UTF-8"?>
<document>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
<item>
Four
</item>
</customer>
<customer>
<item>
One
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
<item>
Four
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
<item>
Four
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
</customer>
</document>But note one thing: the source (the input) could come from over the network.
burrowww.cs.indiana.edu% java IndentingParser http://burrowww.cs.indiana.edu:31090/cgi-bin/foobar/two
<?xml version="1.0" encoding="UTF-8"?>
<document>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
<item>
Four
</item>
</customer>
<customer>
<item>
One
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
<item>
Four
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
<item>
Three
</item>
<item>
Four
</item>
</customer>
<customer>
<item>
One
</item>
<item>
Two
</item>
</customer>
</document>two presented below for conformity. Now let's look at the source code.
burrowww.cs.indiana.edu% cat IndentingParser.java
import org.w3c.dom.*;
import org.apache.xerces.parsers.DOMParser;
public class IndentingParser {
static String displayStrings[] = new String[1000];
static int numberDisplayLines = 0;
public static void displayDocument(String uri) {
try {
DOMParser parser = new DOMParser();
parser.parse(uri);
Document document = parser.getDocument();
display(document, " ");
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
public static void display(Node node, String indent) {
if (node == null) { return; }
int type = node.getNodeType();
switch (type) {
case Node.DOCUMENT_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] +=
"<?xml version=\"1.0\" encoding=\"" + "UTF-8" + "\"?>";
numberDisplayLines++;
display(((Document)node).getDocumentElement(), "");
break;
}
case Node.ELEMENT_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] += "<";
displayStrings[numberDisplayLines] += node.getNodeName();
int length = (node.getAttributes() != null) ?
node.getAttributes().getLength() : 0;
Attr attributes[] = new Attr[length];
for (int loopIndex = 0; loopIndex < length; loopIndex++) {
attributes[loopIndex] =
(Attr)node.getAttributes().item(loopIndex);
}
for (int loopIndex = 0; loopIndex < attributes.length; loopIndex++) {
Attr attribute = attributes[loopIndex];
displayStrings[numberDisplayLines] += " ";
displayStrings[numberDisplayLines] += attribute.getNodeName();
displayStrings[numberDisplayLines] += "=\"";
displayStrings[numberDisplayLines] += attribute.getNodeValue();
displayStrings[numberDisplayLines] += "\"";
}
displayStrings[numberDisplayLines] += ">";
numberDisplayLines++;
NodeList childNodes = node.getChildNodes();
if (childNodes != null) {
length = childNodes.getLength();
indent += " ";
for (int loopIndex = 0; loopIndex < length; loopIndex++) {
display(childNodes.item(loopIndex), indent);
}
}
break;
}
case Node.CDATA_SECTION_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] = "<![CDATA[";
displayStrings[numberDisplayLines] += node.getNodeValue();
displayStrings[numberDisplayLines] += "]]>";
numberDisplayLines++;
break;
}
case Node.TEXT_NODE: {
displayStrings[numberDisplayLines] = indent;
String newText = node.getNodeValue().trim();
if (newText.indexOf("\n") < 0 && newText.length() > 0) {
displayStrings[numberDisplayLines] += newText;
numberDisplayLines++;
}
break;
}
case Node.PROCESSING_INSTRUCTION_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] += "<?";
displayStrings[numberDisplayLines] += node.getNodeName();
String text = node.getNodeValue();
if (text != null && text.length() > 0) {
displayStrings[numberDisplayLines] += text;
}
displayStrings[numberDisplayLines] += "?>";
numberDisplayLines++;
break;
}
} /* switch */
if (type == Node.ELEMENT_NODE) {
displayStrings[numberDisplayLines] =
indent.substring(0, indent.length() - 4);
displayStrings[numberDisplayLines] += "</";
displayStrings[numberDisplayLines] += node.getNodeName();
displayStrings[numberDisplayLines] += ">";
numberDisplayLines++;
indent+= " ";
}
}
public static void main(String[] args) {
displayDocument(args[0]);
for (int loopIndex = 0; loopIndex < numberDisplayLines; loopIndex++) {
System.out.println(displayStrings[loopIndex]);
}
}
}
burrowww.cs.indiana.edu% cat FirstParser.java
import org.w3c.dom.*;
import org.apache.xerces.parsers.DOMParser;
public class FirstParser {
public static void main(String[] args) {
try {
DOMParser parser = new DOMParser();
parser.parse(args[0]);
Document doc = parser.getDocument();
NodeList nodeList = doc.getElementsByTagName("customer");
System.out.println(args[0] + " has " +
nodeList.getLength() +
" <customer> elements. ");
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
}
burrowww.cs.indiana.edu% exit
burrowww.cs.indiana.edu%
script done on Tue Dec 04 09:20:52 2001
What you need to see now is two:
burrowww.cs.indiana.edu% pwd
/nfs/paca/home/user1/dgerman/apache/apache_1.3.20/cgi-bin/foobar
burrowww.cs.indiana.edu% ls -ld two
-rwx------ 1 dgerman faculty 751 Dec 4 07:23 two
burrowww.cs.indiana.edu% cat two
#!/usr/bin/perl
print "Content-type: plain/text\n\n";
print qq{<?xml version="1.0"?>
<document>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
<item> Four </item>
</customer>
<customer>
<item> One </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
<item> Four </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
<item> Three </item>
<item> Four </item>
</customer>
<customer>
<item> One </item>
<item> Two </item>
</customer>
</document>};
burrowww.cs.indiana.edu% After much thought they produced the following output script.
Script started on Tue Dec 04 09:42:17 2001
burrowww.cs.indiana.edu% pwd
/nfs/paca/home/user1/dgerman/apache/apache_1.3.20/cgi-bin/foobar
burrowww.cs.indiana.edu% ls -ld DOM*.pl
-rwxr-xr-x 1 dgerman faculty 900 Dec 4 07:47 DOMreport.pl
burrowww.cs.indiana.edu% cat DOMreport.pl
#!/usr/bin/perl
print "Content-type: plain/text\n\n";
open (AB, "/u/dgerman/foobar/data/dataFile.txt");
@x = <AB>;
close(AB);
print "<?xml version=\"1.0\"?>\n";
print "\n<document>\n";
%library = ();
foreach $line (@x) {
@line = split(/:/, $line);
$isbn = $line[4];
$title = $line[0];
$author = $line[1];
$subject = $line[2];
$publisher = $line[3];
$isbn = $line[4];
$price = $line[5];
$numPages = $line[6];
$description = $line[7];
print qq{
<book>
<subject>$subject</subject>
<title>$title</title>
<author>$author</author>
<publisher>$publisher</publisher>
<numPages>$numPages</numPages>
<saleDetails>
<isbn>$isbn</isbn>
<price>$price</price>
</saleDetails>
<description>$description</description>
</book>};
}
print "</document>";
burrowww.cs.indiana.edu% ./DOMreport.pl
Content-type: plain/text
<?xml version="1.0"?>
<document>
<book>
<subject>Biography</subject>
<title>In Search of Lake Wobegon</title>
<author>Garrison Keillor, Richard Olsenius (Photographer)</author>
<publisher>Viking Press</publisher>
<numPages>128</numPages>
<saleDetails>
<isbn>0-6700-3037-6</isbn>
<price>29.95</price>
</saleDetails>
<description>In the twenty-five years since Garrison Keillor first brought it to life, the rural Minnesota town of Lake Wobegon has become a national treasure. In this lavishly produced photography book, word and image combine to illuminate the real Minnesota town-life, landscapes, and people who inspired its creation. Taking us on a tour of Stearns County, the Minnesota county he deems most "Wobegonic," Keillor meditates on the origins of the place where, as a young writer, he found the inspiration for his fiction and his radio show. As an artful evocation of Keillor's beloved invention, Richard Olsenius's elegantly composed black-and-white photographs of rural Minnesota capture the dignity of his subjects, the beauties of the landscape as well as the enduring values and eccentricities of the communities rooted there.
</description>
</book>
<book>
<subject>Science</subject>
<title>The Armchair Universe - An Exploration of Computer Worlds </title>
<author>A. K. Dewdney </author>
<publisher>W. H. Freeman and Company, New York </publisher>
<numPages>330</numPages>
<saleDetails>
<isbn>0-7167-1939-8</isbn>
<price>19.90</price>
</saleDetails>
<description>This is the first collection of A.K.Dewdney's popular "Computer Recreations" columns, drawn from Scientific American magazine between 1984 and 1987. Inspired by Martin Gardner's classic "Mathematical Games" column, which entertained millions of readers for more than 30 years, "Computer Recreations" has quickly become one of the most widely read and anticipated columns in Scientific American. The computer recreations described here range from purely entertaining brainteasers to more practical computer applications of scientific thought. And with Dewdney's lucid programming directions to follow, you can actually sit at your computer and try your hand at them all. Available in paperback and hardcover. Cover image shows Julia set bounding three basins of attraction on a Riemann sphere.
</description>
</book></document>burrowww.cs.indiana.edu% exit
burrowww.cs.indiana.edu%
script done on Tue Dec 04 09:42:43 2001
(Sometimes raw data can be in just the right format.)
Company B can now easily interact with Company A.
Script started on Tue Dec 04 09:56:51 2001
burrowww.cs.indiana.edu% pwd
/nfs/paca/home/user1/dgerman/apache/jakarta-tomcat-3.2.3/webapps/examples/WEB-INF/classes
burrowww.cs.indiana.edu% echo $myServlets
/u/dgerman/apache/jakarta-tomcat-3.2.3/webapps/examples/WEB-INF/classes
burrowww.cs.indiana.edu% ls -ld Nine.java Ten.java
-rw-r--r-- 1 dgerman faculty 870 Dec 4 07:38 Nine.java
-rw-r--r-- 1 dgerman faculty 746 Dec 4 07:57 Ten.java
burrowww.cs.indiana.edu% cat Nine.java
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
import org.w3c.dom.*;
import org.apache.xerces.parsers.DOMParser;
public class Nine extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
try {
String url = "http://burrowww.cs.indiana.edu:31090/cgi-bin/foobar/two";
DOMParser parser = new DOMParser();
parser.parse(url);
Document doc = parser.getDocument();
NodeList nodeList = doc.getElementsByTagName("customer");
out.println(url + " has " +
nodeList.getLength() +
" <customer> elements. ");
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
}The next servlet simply uses an external class (that we have already seen).
burrowww.cs.indiana.edu% cat Ten.java
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class Ten extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws IOException, ServletException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String url = "http://burrowww.cs.indiana.edu:31090/cgi-bin/foobar/DOMreport.pl";
IndentingParser.displayDocument(url);
for (int loopIndex = 0; loopIndex < IndentingParser.numberDisplayLines; loopIndex++) {
out.println(IndentingParser.displayStrings[loopIndex]);
}
}
}IndentingParser.java class again.
burrowww.cs.indiana.edu% cat IndentingParser.java
import org.w3c.dom.*;
import org.apache.xerces.parsers.DOMParser;
public class IndentingParser {
static String displayStrings[] = new String[1000];
static int numberDisplayLines = 0;
public static void displayDocument(String uri) {
try {
DOMParser parser = new DOMParser();
parser.parse(uri);
Document document = parser.getDocument();
display(document, " ");
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
public static void display(Node node, String indent) {
if (node == null) { return; }
int type = node.getNodeType();
switch (type) {
case Node.DOCUMENT_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] +=
"<?xml version=\"1.0\" encoding=\"" + "UTF-8" + "\"?>";
numberDisplayLines++;
display(((Document)node).getDocumentElement(), "");
break;
}
case Node.ELEMENT_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] += "<";
displayStrings[numberDisplayLines] += node.getNodeName();
int length = (node.getAttributes() != null) ?
node.getAttributes().getLength() : 0;
Attr attributes[] = new Attr[length];
for (int loopIndex = 0; loopIndex < length; loopIndex++) {
attributes[loopIndex] =
(Attr)node.getAttributes().item(loopIndex);
}
for (int loopIndex = 0; loopIndex < attributes.length; loopIndex++) {
Attr attribute = attributes[loopIndex];
displayStrings[numberDisplayLines] += " ";
displayStrings[numberDisplayLines] += attribute.getNodeName();
displayStrings[numberDisplayLines] += "=\"";
displayStrings[numberDisplayLines] += attribute.getNodeValue();
displayStrings[numberDisplayLines] += "\"";
}
displayStrings[numberDisplayLines] += ">";
numberDisplayLines++;
NodeList childNodes = node.getChildNodes();
if (childNodes != null) {
length = childNodes.getLength();
indent += " ";
for (int loopIndex = 0; loopIndex < length; loopIndex++) {
display(childNodes.item(loopIndex), indent);
}
}
break;
}
case Node.CDATA_SECTION_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] = "<![CDATA[";
displayStrings[numberDisplayLines] += node.getNodeValue();
displayStrings[numberDisplayLines] += "]]>";
numberDisplayLines++;
break;
}
case Node.TEXT_NODE: {
displayStrings[numberDisplayLines] = indent;
String newText = node.getNodeValue().trim();
if (newText.indexOf("\n") < 0 && newText.length() > 0) {
displayStrings[numberDisplayLines] += newText;
numberDisplayLines++;
}
break;
}
case Node.PROCESSING_INSTRUCTION_NODE: {
displayStrings[numberDisplayLines] = indent;
displayStrings[numberDisplayLines] += "<?";
displayStrings[numberDisplayLines] += node.getNodeName();
String text = node.getNodeValue();
if (text != null && text.length() > 0) {
displayStrings[numberDisplayLines] += text;
}
displayStrings[numberDisplayLines] += "?>";
numberDisplayLines++;
break;
}
} /* switch */
if (type == Node.ELEMENT_NODE) {
displayStrings[numberDisplayLines] =
indent.substring(0, indent.length() - 4);
displayStrings[numberDisplayLines] += "</";
displayStrings[numberDisplayLines] += node.getNodeName();
displayStrings[numberDisplayLines] += ">";
numberDisplayLines++;
indent+= " ";
}
}
public static void main(String[] args) {
displayDocument(args[0]);
for (int loopIndex = 0; loopIndex < numberDisplayLines; loopIndex++) {
System.out.println(displayStrings[loopIndex]);
}
}
}
burrowww.cs.indiana.edu% ls -ld Indent*.java
-rw-r--r-- 1 dgerman faculty 3693 Dec 4 07:52 IndentingParser.java
burrowww.cs.indiana.edu% javac Nine.java
burrowww.cs.indiana.edu% javac Ten.java
burrowww.cs.indiana.edu%
script done on Tue Dec 04 09:57:55 2001Try the servlet Nine.
Try Ten. Is it working? Why or why not.
End of lecture.
Tomorrow in lab you will look at this again, so you can understand it better. The exam will be available on Wednesday night. It will ask you to produce the servlet and JSP implementations of Homework 2 and 3 (and 5,) that is, the calculator and portfolio. And that would be it.
What we discussed above becomes your Project Exam. If you have a project and are done with it, turn in a paper (two pages at most) that describes it. Include in the paper all the URLs that I should check on your web sites. If you do not have a project, and are waiting for the notes for the default project, read these notes above, understand them, take the lab tomorrow, and answer the questions that will be asked and posted on-line.
Turn your final and your project paper together, in person, before or on Dec 14 (5-7pm in LH102). There will be a set of lab notes posted tomorrow, and the text of the final will be posted where lecture notes for Thursday would have been posted normally. I hope you enjoyed these notes, and the class.
Please let me know if you need any help.
