import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
/** Prints non-detailed reports of mouse events.
* Uses the low-level processXxxEvent methods instead
* of the usual event listeners.
*
*****************
public class MouseReporter extends Applet {
public void init() {
setBackground(Color.blue); // So you can see applet in page
enableEvents(AWTEvent.MOUSE_EVENT_MASK |
AWTEvent.MOUSE_MOTION_EVENT_MASK);
}
public void processMouseEvent(MouseEvent event) {
System.out.println("Mouse enter/exit or click at (" +
event.getX() + "," +
event.getY() + ").");
// In case there are MouseListeners attached:
super.processMouseEvent(event);
}
public void processMouseMotionEvent(MouseEvent event) {
System.out.println("Mouse move/drag at (" +
event.getX() + "," +
event.getY() + ").");
// In case there are MouseMotionListeners attached:
super.processMouseMotionEvent(event);
}
}
Aug 28
Applet that uses processXxx methods to print detailed reports on mouse events. Illustrates low-level alternative to handling events with listeners.
Aug 28
HeadingExample.jsp Page that uses the HeadingTag custom tag
HeadingExample.jsp Page that uses the HeadingTag custom tag
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!--
Illustration of HeadingTag tag.
Taken from Core Web Programming Java 2 Edition
from Prentice Hall and Sun Microsystems Press,
.
May be freely used or adapted.
-->
<HTML>
<HEAD>
<TITLE>Some Tag-Generated Headings</TITLE>
</HEAD>
<BODY>
<%@ taglib uri="cwp-taglib.tld" prefix="cwp" %>
<cwp:heading bgColor="#C0C0C0">
Default Heading
</cwp:heading>
<P>
<cwp:heading bgColor="BLACK" color="WHITE">
White on Black Heading
</cwp:heading>
<P>
<cwp:heading bgColor="#EF8429" fontSize="60" border="5">
Large Bordered Heading
</cwp:heading>
<P>
<cwp:heading bgColor="CYAN" width="100%">
Heading with Full-Width Background
</cwp:heading>
<P>
<cwp:heading bgColor="CYAN" fontSize="60"
fontList="Brush Script MT, Times, serif">
Heading with Non-Standard Font
</cwp:heading>
</BODY>
</HTML>
package cwp.tags;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
/** Generates an HTML heading with the specified background
* color, foreground color, alignment, font, and font size.
* You can also turn on a border around it, which normally
* just barely encloses the heading, but which can also
* stretch wider. All attributes except the background
* color are optional.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class HeadingTag extends TagSupport {
private String bgColor; // The one required attribute
private String color = null;
private String align="CENTER";
private String fontSize="36";
private String fontList="Arial, Helvetica, sans-serif";
private String border="0";
private String width=null;
public void setBgColor(String bgColor) {
this.bgColor = bgColor;
}
public void setColor(String color) {
this.color = color;
}
public void setAlign(String align) {
this.align = align;
}
public void setFontSize(String fontSize) {
this.fontSize = fontSize;
}
public void setFontList(String fontList) {
this.fontList = fontList;
}
public void setBorder(String border) {
this.border = border;
}
public void setWidth(String width) {
this.width = width;
}
public int doStartTag() {
try {
JspWriter out = pageContext.getOut();
out.print("<TABLE BORDER=" + border +
" BGCOLOR=\"" + bgColor + "\"" +
" ALIGN=\"" + align + "\"");
if (width != null) {
out.print(" WIDTH=\"" + width + "\"");
}
out.print("><TR><TH>");
out.print("<SPAN STYLE=\"" +
"font-size: " + fontSize + "px; " +
"font-family: " + fontList + "; ");
if (color != null) {
out.println("color: " + color + ";");
}
out.print("\"> "); // End of <SPAN ...>
} catch(IOException ioe) {
System.out.println("Error in HeadingTag: " + ioe);
}
return(EVAL_BODY_INCLUDE); // Include tag body
}
public int doEndTag() {
try {
JspWriter out = pageContext.getOut();
out.print("</SPAN></TABLE>");
} catch(IOException ioe) {
System.out.println("Error in HeadingTag: " + ioe);
}
return(EVAL_PAGE); // Continue with rest of JSP page
}
}
Aug 28
PrimeExample.jsp Page that uses the PrimeTag custom tag
PrimeExample.jsp Page that uses the PrimeTag custom tag
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!--
Illustration of PrimeTag tag.
Taken from Core Web Programming Java 2 Edition
from Prentice Hall and Sun Microsystems Press,
.
May be freely used or adapted.
-->
<HTML>
<HEAD>
<TITLE>Some N-Digit Primes</TITLE>
<LINK REL=STYLESHEET
HREF="JSP-Styles.css"
TYPE="text/css">
</HEAD>
<BODY>
<H1>Some N-Digit Primes</H1>
<%@ taglib uri="cwp-taglib.tld" prefix="cwp" %>
<UL>
<LI>20-digit: <cwp:prime length="20" />
<LI>40-digit: <cwp:prime length="40" />
<LI>80-digit: <cwp:prime length="80" />
<LI>Default (50-digit): <cwp:prime />
</UL>
</BODY>
</HTML>
package cwp.tags;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
/** Generates an N-digit random prime (default N = 50).
* Extends SimplePrimeTag, adding a length attribute
* to set the size of the prime. The doStartTag
* method of the parent class uses the len field
* to determine the approximate length of the prime.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class PrimeTag extends SimplePrimeTag {
public void setLength(String length) {
try {
len = Integer.parseInt(length);
} catch(NumberFormatException nfe) {
len = 50;
}
}
}
Aug 28
SimplePrimeExample.jsp Page that uses the SimplePrimeTag custom tag
SimplePrimeExample.jsp Page that uses the SimplePrimeTag custom tag <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- Illustration of SimplePrimeTag tag. Taken from Core Web Programming Java 2 Edition from Prentice Hall and Sun Microsystems Press, . May be freely used or adapted. --> <HTML> <HEAD> <TITLE>Some 50-Digit Primes</TITLE> <LINK REL=STYLESHEET HREF="JSP-Styles.css" TYPE="text/css"> </HEAD> <BODY> <H1>Some 50-Digit Primes</H1> <%@ taglib uri="cwp-taglib.tld" prefix="cwp" %> <UL> <LI><cwp:simplePrime /> <LI><cwp:simplePrime /> <LI><cwp:simplePrime /> <LI><cwp:simplePrime /> </UL> </BODY> </HTML>
Aug 28
SimpleExample.jsp Page that uses the ExampleTag custom tag.
SimpleExample.jsp Page that uses the ExampleTag custom tag.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!--
Illustration of very simple JSP custom tag.
Taken from Core Web Programming Java 2 Edition
from Prentice Hall and Sun Microsystems Press,
.
May be freely used or adapted.
-->
<HTML>
<HEAD>
<%@ taglib uri="cwp-taglib.tld" prefix="cwp" %>
<TITLE><cwp:example /></TITLE>
<LINK REL=STYLESHEET
HREF="JSP-Styles.css"
TYPE="text/css">
</HEAD>
<BODY>
<H1><cwp:example /></H1>
<cwp:example />
</BODY>
</HTML>
ExampleTag
package cwp.tags;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
/** Very simple JSP tag that just inserts a string
* ("Custom tag example...") into the output.
* The actual name of the tag is not defined here;
* that is given by the Tag Library Descriptor (TLD)
* file that is referenced by the taglib directive
* in the JSP file.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class ExampleTag extends TagSupport {
public int doStartTag() {
try {
JspWriter out = pageContext.getOut();
out.print("Custom tag example " +
"(cwp.tags.ExampleTag)");
} catch(IOException ioe) {
System.out.println("Error in ExampleTag: " + ioe);
}
return(SKIP_BODY);
}
}
Aug 28
ExampleTag.java Very simple custom tag. Remember to install it in the WEB-INF/classes/cwp/tags directory.
ExampleTag.java Very simple custom tag. Remember to install it in the WEB-INF/classes/cwp/tags directory.
package cwp.tags;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import java.io.*;
/** Very simple JSP tag that just inserts a string
* ("Custom tag example...") into the output.
* The actual name of the tag is not defined here;
* that is given by the Tag Library Descriptor (TLD)
* file that is referenced by the taglib directive
* in the JSP file.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class ExampleTag extends TagSupport {
public int doStartTag() {
try {
JspWriter out = pageContext.getOut();
out.print("Custom tag example " +
"(cwp.tags.ExampleTag)");
} catch(IOException ioe) {
System.out.println("Error in ExampleTag: " + ioe);
}
return(SKIP_BODY);
}
}
Aug 28
AccessCountBean.java Bean used to illustrate the difference between running jsp:setProperty for every request vs. only when the object is created
AccessCountBean.java Bean used to illustrate the difference between running jsp:setProperty for every request vs. only when the object is created
package cwp;
/** Simple bean to illustrate sharing beans through
* use of the scope attribute of jsp:useBean.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class AccessCountBean {
private String firstPage;
private int accessCount = 1;
public String getFirstPage() {
return(firstPage);
}
public void setFirstPage(String firstPage) {
this.firstPage = firstPage;
}
public int getAccessCount() {
return(accessCount++);
}
}
Aug 28
SaleEntry2.jsp Page that uses the SaleEntry bean, using the param attribute to read request parameters and assign them to bean properties
SaleEntry2.jsp Page that uses the SaleEntry bean, using the param attribute to read request parameters and assign them to bean properties
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!--
Example of using jsp:setProperty and an explicity association
with an input parameter. See SaleEntry1.jsp
and SaleEntry3.jsp for alternatives.
Taken from Core Web Programming Java 2 Edition
from Prentice Hall and Sun Microsystems Press,
.
May be freely used or adapted.
-->
<HTML>
<HEAD>
<TITLE>Using jsp:setProperty</TITLE>
<LINK REL=STYLESHEET
HREF="JSP-Styles.css"
TYPE="text/css">
</HEAD>
<BODY>
<TABLE BORDER=5 ALIGN="CENTER">
<TR><TH CLASS="TITLE">
Using jsp:setProperty</TABLE>
<jsp:useBean id="entry" class="cwp.SaleEntry" />
<jsp:setProperty
name="entry"
property="itemID"
param="itemID" />
<jsp:setProperty
name="entry"
property="numItems"
param="numItems" />
<%-- WARNING! Both the JSWDK 1.0.1 and the Java Web Server
have a bug that makes them fail on double
type conversions of the following sort.
--%>
<jsp:setProperty
name="entry"
property="discountCode"
param="discountCode" />
<BR>
<TABLE ALIGN="CENTER" BORDER=1>
<TR CLASS="COLORED">
<TH>Item ID<TH>Unit Price<TH>Number Ordered<TH>Total Price
<TR ALIGN="RIGHT">
<TD><jsp:getProperty name="entry" property="itemID" />
<TD>$<jsp:getProperty name="entry" property="itemCost" />
<TD><jsp:getProperty name="entry" property="numItems" />
<TD>$<jsp:getProperty name="entry" property="totalCost" />
</TABLE>
</BODY>
</HTML>
SaleEntry.java //SaleEntry Bean
package cwp;
/** Simple bean to illustrate the various forms
* of jsp:setProperty.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class SaleEntry {
private String itemID = "unknown";
private double discountCode = 1.0;
private int numItems = 0;
public String getItemID() {
return(itemID);
}
public void setItemID(String itemID) {
if (itemID != null) {
this.itemID = itemID;
} else {
this.itemID = "unknown";
}
}
public double getDiscountCode() {
return(discountCode);
}
public void setDiscountCode(double discountCode) {
this.discountCode = discountCode;
}
public int getNumItems() {
return(numItems);
}
public void setNumItems(int numItems) {
this.numItems = numItems;
}
// In real life, replace this with database lookup.
public double getItemCost() {
double cost;
if (itemID.equals("a1234")) {
cost = 12.99*getDiscountCode();
} else {
cost = -9999;
}
return(roundToPennies(cost));
}
private double roundToPennies(double cost) {
return(Math.floor(cost*100)/100.0);
}
public double getTotalCost() {
return(getItemCost() * getNumItems());
}
}
Aug 28
SaleEntry.java Bean used to demonstrate the various approaches to reading request parameters and stuffing them into Java objects.
package cwp;
/** Simple bean to illustrate the various forms
* of jsp:setProperty.
* <P>
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* .
* May be freely used or adapted.
*/
public class SaleEntry {
private String itemID = "unknown";
private double discountCode = 1.0;
private int numItems = 0;
public String getItemID() {
return(itemID);
}
public void setItemID(String itemID) {
if (itemID != null) {
this.itemID = itemID;
} else {
this.itemID = "unknown";
}
}
public double getDiscountCode() {
return(discountCode);
}
public void setDiscountCode(double discountCode) {
this.discountCode = discountCode;
}
public int getNumItems() {
return(numItems);
}
public void setNumItems(int numItems) {
this.numItems = numItems;
}
// In real life, replace this with database lookup.
public double getItemCost() {
double cost;
if (itemID.equals("a1234")) {
cost = 12.99*getDiscountCode();
} else {
cost = -9999;
}
return(roundToPennies(cost));
}
private double roundToPennies(double cost) {
return(Math.floor(cost*100)/100.0);
}
public double getTotalCost() {
return(getItemCost() * getNumItems());
}
}
Aug 28
The class that actually gets the strings over the network by means of an ObjectInputStream via HTTP tunneling.
import java.net.*;
import java.io.*;
/** When this class is built, it returns a value
* immediately, but this value returns false for isDone
* and null for getQueries. Meanwhile, it starts a Thread
* to request an array of query strings from the server,
* reading them in one fell swoop by means of an
* ObjectInputStream. Once they've all arrived, they
* are placed in the location getQueries returns,
* and the isDone flag is switched to true.
* Used by the ShowQueries applet.
*
* Taken from Core Web Programming Java 2 Edition
* from Prentice Hall and Sun Microsystems Press,
* May be freely used or adapted.
*/
public class QueryCollection implements Runnable {
private String[] queries;
private String[] tempQueries;
private boolean isDone = false;
private URL dataURL;
public QueryCollection(String urlSuffix, URL currentPage) {
try {
// Only the URL suffix need be supplied, since
// the rest of the URL is derived from the current page.
String protocol = currentPage.getProtocol();
String host = currentPage.getHost();
int port = currentPage.getPort();
dataURL = new URL(protocol, host, port, urlSuffix);
Thread queryRetriever = new Thread(this);
queryRetriever.start();
} catch(MalformedURLException mfe) {
isDone = true;
}
}
public void run() {
try {
tempQueries = retrieveQueries();
queries = tempQueries;
} catch(IOException ioe) {
tempQueries = null;
queries = null;
}
isDone = true;
}
public String[] getQueries() {
return(queries);
}
public boolean isDone() {
return(isDone);
}
private String[] retrieveQueries() throws IOException {
URLConnection connection = dataURL.openConnection();
// Make sure browser doesn't cache this URL, since
// I want different queries for each request.
connection.setUseCaches(false);
// Use ObjectInputStream so I can read a String[]
// all at once.
ObjectInputStream in =
new ObjectInputStream(connection.getInputStream());
try {
// The return type of readObject is Object, so
// I need a typecast to the actual type.
String[] queryStrings = (String[])in.readObject();
return(queryStrings);
} catch(ClassNotFoundException cnfe) {
return(null);
}
}
}
