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Internet Technologies
XML Messaging
A PowerWarning application using servlets and SAX
Asynchronous Messages using JAXM and SOAP
The PowerWarning Application is from “XML and
Java” by Maruyama, Tamura, and Uramoto, Addison-Wesley.
The JAXM example was adapted with major changes from “Java Web Services” by Deitel
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and Deitel
XML Messaging Part I
The PowerWarning application allows users to register
their geographical position and their temperature concerns.
Users will receive e-mail when the temperature exceeds the user
specified parameters.
This example is from
“XML and Java” by Maruyama, Tamura, and Uramoto, Addison-Wesley.
The web container is called Jigsaw from the W3C.
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Suppose that we know that the weather information is available
from the web at
http://www.xweather.com/White_Plains_NY_US.html.
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
<html>
<head>
<title>Weather Report</title>
</head>
<body>
<h2>Weather Report -- White Plains, NY </h2>
<table border=1>
<tr><td>Date/Time</td><td align=center>11 AM EDT Sat Jul 25
1998</td></tr>
[9]
<tr><td>Current Tem.</td><td align=center>70°</td></tr>
[10]
<tr><td>Today’s High</td><td align=center>82°</td></tr>
[11]
<tr><td>Today’s Low</td><td align=center>62°</td><tr>
[12] </table>
[13] </body>
[14] </html>
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•Strategy 1:
For the current temperature of White Plains, go to line 9,
column 46 of the page and continue until reaching the next
ampersand.
•Strategy 2:
For the current temperature of the White Plains, go to the
first <table> tag, then go to the second <tr> tag within the
table, and then go to the second <tg> tag within the row.
Neither of these seems very appealing…
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<?xml version=“1.0”?>
<!DOCTYPE WeatherReport SYSTEM
“http>//www.xweather.com/WeatherReport.dtd”>
<WeatherReport>
<City>White Plains</City>
XML would help
<State>NY</State>
<Date>Sat Jul 25 1998</Date>
<Time>11 AM EDT</Time>
<CurrTemp unit=“Farenheit”>70</CurrTemp>
<High unit=“Farenheit”>82</High>
<Low unit=“Farenheit”>62</Low>
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</Weather Report>
5
•Strategy 3:
For the current temperature of White Plains, N.Y., go
to the <CurrTemp> tag.
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WeatherReport
application
Mobile users
XSLT
WML
HTML
XML
PC users
Http://www.xweather.com
PowerWarning
application
XML
Email notifications
XML
Application
programs
Registrations
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The XML Describing the Weather
<?xml version="1.0" encoding="UTF-8"?>
This file is behind
<WeatherReport>
Jigsaw in the file
<City>Pittsburgh</City>
Www/weather/
<State>PA</State>
weather.xml.
<Date>Wed. April 11, 2001</Date>
<Time>3</Time>
<CurrTemp Unit = "Farenheit">70</CurrTemp>
<High Unit = "Farenheit">82</High>
Perhaps this is
<Low Unit = "Farenheit">62</Low>
being served up
</WeatherReport>
by www.xweather.com
for ½ cents per hit.
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Serving the weather
// This servlet file is stored in Www/Jigsaw/servlet/GetWeather.java
// This servlet returns a user selected xml weather file from
// the Www/weather directory and returns it to the client.
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
This data would not
normally be retrieved
from a file.
public class GetWeather extends HttpServlet {
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public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
String theData = "";
/* For simplicity we get the user’s request from the path. */
String extraPath = req.getPathInfo();
extraPath = extraPath.substring(1);
// read the file
try {
// open file and create a DataInputStream
FileInputStream theFile =
new FileInputStream("c:\\Jigsaw\\Jigsaw\\”+
“Jigsaw\\Www\\weather\\"+extraPath);
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InputStreamReader is = new InputStreamReader(theFile);
BufferedReader br = new BufferedReader(is);
// read the file into the string theData
String thisLine;
while((thisLine = br.readLine()) != null) {
theData += thisLine + "\n";
}
}
catch(Exception e) {
System.err.println("Error " + e);
}
PrintWriter out = res.getWriter();
out.write(theData);
System.out.println("Wrote document to client");
out.close();
}
}
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WeatherReport
application
Mobile users
XSLT
WML
HTML
XML
PC users
Http://www.xweather.com
PowerWarning
application
XML
Email notifications
XML
Application
programs
Registrations
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Registrations (HTML)
<!-- PowerWarningForm.html -->
<html>
<head>
<title>PowerWarning</title>
</head>
<body>
<form method="post" action="/servlet/PowerWarn">
E-Mail
<input type="text" name = "User"> <p>
State
<input type="text" name = "State"> <p>
City
<input type="text" name = "City"> <p>
Temperature
<input type="text" name = "Temperature"> <p>
Duration
<input type="text" name = "Duration"> <p>
<input type = "submit">
</form>
</body>
</html>
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Registrations (Servlet)
The servlet will create a watcher object for each registered
user. The watcher object will be told of each user’s location
and temperature requirements. Each watcher object will run
in its own thread and may or may not notify its assigned
user by email.
On servlet initialization, we will start up an object whose
responsibility it is to periodically wake up and tell the watcher
objects to check the weather.
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Registrations (Servlet)
/* This servlet is called by an HTML form. The form passes
the user email, state, city, temperature and duration.
*/
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class PowerWarn extends HttpServlet {
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static Hashtable userTable;
/* Holds (email,watcher) pairs */
public void init(ServletConfig conf) throws ServletException {
super.init(conf);
PowerWarn.userTable = new Hashtable();
Scheduler scheduler = new Scheduler();
scheduler.start();
/* Run the scheduler */
}
/* The scheduler can see the hash
table. It has package access.
*/
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public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
/* Collect data from the HTML form */
String par_user =
String par_state =
String par_city =
int par_temp =
req.getParameter("User");
req.getParameter("State");
req.getParameter("City");
Integer.parseInt(
req.getParameter("Temperature"));
int par_duration = Integer.parseInt(
req.getParameter("Duration"));
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/* Assign a watcher to this user. */
Watcher watcher = new Watcher(par_user, par_state, par_city,
par_temp, par_duration);
/* Place the (email,watcher) pair in the hash table. */
PowerWarn.userTable.put(par_user, watcher);
res.setContentType("text/html");
PrintWriter writer = res.getWriter();
writer.print("<html><head></head><body><b>” +
“You'll be notified by email</b></body></html>");
writer.close();
}
}
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Servlet
Http Request
PowerWarn.userTable
Watcher
[email protected]
Email
User
data
Http Request
Watcher
User
data
[email protected]
Email
Scheduler
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The Scheduler
import java.util.Enumeration;
public class Scheduler extends Thread {
public void run() {
System.out.println("Running scheduler");
while(true) {
Enumeration en = PowerWarn.userTable.elements();
while(en.hasMoreElements()) {
Watcher wa = (Watcher)en.nextElement();
new Thread(wa).start();
}
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try {
/* put this thread to sleep for 15 seconds */
Thread.sleep(1000 * 15);
}
catch(InterruptedException ie) {
// ignore
}
} /* end while */
}
Fifteen seconds for
testing.
public Scheduler() {
super();
}
}
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The Watcher Class
The Watcher objects make HTTP requests to get XML.
How should we handle the XML? SAX or DOM? SAX.
How do we send email? JavaMail.
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import org.xml.sax.*;
import org.xml.sax.helpers.ParserFactory;
import java.io.*;
import java.net.*;
import org.w3c.dom.Document;
import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
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public class Watcher extends HandlerBase implements Runnable {
String user, state, city;
int temp, duration, overTemp;
public Watcher(String user, String state, String city, int temp,
int duration) {
super();
this.user = user;
this.state = state;
this.city = city;
this.temp = temp;
this.duration = duration;
this.overTemp = 0;
}
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public void run() { // called by scheduler
System.out.println("Running watcher");
/* Set up to call the weather service. */
String weatheruri =
“http://mccarthy.heinz.cmu.edu:8001/servlet/GetWeather”+
“/weather.xml";
/* For simplicity we won’t take the appropriate approach. */
/* String weatheruri =
"http://mccarthy.heinz.cmu.edu:8001/servlet/GetWeather/?city="
+ URLEncoder.encode(this.city);
*/
/* Create an InputSource object for the parser to use. */
InputSource is = new InputSource(weatheruri);
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try {
/* Set up to handle incoming XML */
SAXParserFactory factory = SAXParserFactory.newInstance();
factory.setValidating(true);
SAXParser parser = factory.newSAXParser();
parser.parse(is, this); /* The parser makes the calls. */
}
catch(Exception e) {
e.printStackTrace();
return;
}
/* The parsing and callbacks are done by this time. */
int currentTempNumber;
try {
currentTempNumber = Integer.parseInt(this.currentTemp.trim());
}
catch( NumberFormatException e) {e.printStackTrace(); return; }
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/* See if the user wants to be alerted. */
if(currentTempNumber > this.temp) {
this.overTemp++;
if(this.overTemp >= this.duration) {
warning();
}
}
else {
this.overTemp = 0;
}
}
/* Send email via JavaMail. The Mailer class is based on the JavaMail API. */
public void warning() {
System.out.println("Sending email");
Mailer mailman = new Mailer(this.user,
"[email protected]", "It's hot");
mailman.send();
}
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/* Handle SAX events. */
StringBuffer buffer;
String currentTemp;
public void startDocument() throws SAXException {
this.currentTemp = null;
}
public void startElement(String name, AttributeList aMap) throws SAXException {
if(name.equals("CurrTemp")) { /* Prepare for next event. */
this.buffer = new StringBuffer();
}
}
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public void endElement(String name) throws SAXException {
if(name.equals("CurrTemp")) {
this.currentTemp = this.buffer.toString();
this.buffer = null;
}
}
public void characters(char[] ch, int start, int length) throws SAXException {
if(this.buffer != null) this.buffer.append(ch,start,length);
}
}
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WeatherReport
application
Mobile users
WML
HTML
XML
PC users
Http://www.xweather.com
PowerWarning
application
XML
Email notifications
XML
Application
programs
Registrations
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XML Messaging JAXM
We
enter
two
numbers
to be
added.
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We hear
back right
away that
the computation
will be performed.
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Check
another
page to
see if
our
computation
has been
completed.
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ResultHolder.java
Browser
JAXM Servlet
ResultHandler
HTTPServlet
GetResultsAsHTML
Browser Two numbers
HTTP Servlet
DoCalculationServlet
Feedback to browser
right away
JAXM Message Provider
JAXM Servlet
CalculationHandler
JAXM Message Provider
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Configure the Provider
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With a URI
we
name
the provider
A URL
Is the
Provider
location
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Set the classpath
.;
d:\jwsdp-1_0_01\common\lib\jaxm-api.jar;
d:\jwsdp-1_0_01\common\lib\jaxm-runtime.jar;
d:\jwsdp-1_0_01\services\jaxm-provider;
d:\jwsdp-1_0_01\services\jaxm-provideradmin;
d:\jwsdp-1_0_01\common\lib\saaj-api.jar;
d:\jwsdp-1_0_01\common\lib\saaj-ri.jar;
d:\jwsdp-1_0_01\common\lib\dom4j.jar;
d:\jwsdp-1_0_01\common\lib\activation.jar;
d:\jwsdp-1_0_01\common\lib\mail.jar;
d:\jwsdp-1_0_01\common\lib\commons-logging.jar;
d:\jwsdp-1_0_01\common\lib\jaxp-api.jar;
d:\jwsdp-1_0_01\common\endorsed\dom.jar;
d:\jwsdp-1_0_01\common\endorsed\sax.jar;
d:\jwsdp-1_0_01\common\endorsed\xalan.jar;
d:\jwsdp-1_0_01\common\endorsed\xercesImpl.jar;
d:\jwsdp-1_0_01\common\endorsed\xsltc.jar;
d:\xerces\xmlParserAPIs.jar;
d:\jwsdp-1_0_01\common\lib\servlet.jar;
d:\jwsdp-1_0_01\common\lib\soap.jar;
d:\jwsdp-1_0_01\common\lib\providerutil.jar
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Provide two client.xml files
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE ClientConfig
PUBLIC "-//Sun Microsystems, Inc.//DTD JAXM Client//EN"
"http://java.sun.com/xml/dtds/jaxm_client_1_0.dtd">
<ClientConfig>
<Endpoint>urn:edu.cmu.andrew.mm6.serverProvider</Endpoint>
<CallbackURL>
http://127.0.0.1:8080/jaxmasync/servercode/CalculationHandler
</CallbackURL>
<Provider>
<URI>http://java.sun.com/xml/jaxm/provider</URI>
<URL>http://127.0.0.1:8081/jaxm-provider/sender</URL>
</Provider>
</ClientConfig>
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On the server
38 side
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE ClientConfig
PUBLIC "-//Sun Microsystems, Inc.//DTD JAXM Client//EN"
"http://java.sun.com/xml/dtds/jaxm_client_1_0.dtd">
<ClientConfig>
<Endpoint>urn:edu.cmu.andrew.mm6.clientProvider
</Endpoint>
<CallbackURL>http://127.0.0.1:8080/jaxmasync/clientcode/ResultHandler
</CallbackURL>
<Provider>
<URI>http://java.sun.com/xml/jaxm/provider</URI>
<URL>http://127.0.0.1:8081/jaxm-provider/sender</URL>
</Provider>
</ClientConfig>
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On the client side
Server Side Directories
jaxmasync/servercode
|
├───build
│ └───WEB-INF
│
├───classes
│
└───lib
├───docs
├───src -- CalculationHandler.java
└───web – index.html
| └───WEB-INF – web.xml
|
└───classes – client.xml
| build.properties
| build.xml
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Client Side Directories
D:\McCarthy\www\95-733\examples\jaxmasync\clientcode>tree
|
├───build
│ └───WEB-INF
│
├───classes
│
└───lib
├───docs
├───src
DoCalculationServlet.java
└───web – index.html
GetResultAsHTML.java
└───WEB-INF – web.xml
ResultHandler.java
|
└───classes – client.xml
ResultHolder.java
|build.properties
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|build.xml
Client Side Web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
<servlet>
<servlet-name>GetDataFromHTML
</servlet-name>
<servlet-class>
DoCalculationServlet
</servlet-class>
</servlet>
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<servlet>
<servlet-name>HandleResult
</servlet-name>
<servlet-class>
ResultHandler
</servlet-class>
</servlet>
<servlet>
<servlet-name>HTMLServlet</servlet-name>
<servlet-class>GetResultAsHTML</servlet-class>
</servlet>
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<servlet-mapping>
<servlet-name>HTMLServlet</servlet-name>
<url-pattern>/GetResultAsHTML/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>
GetDataFromHTML
</servlet-name>
<url-pattern>
/DoCalculationServlet/*
</url-pattern>
</servlet-mapping>
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<servlet-mapping>
<servlet-name>
HandleResult
</servlet-name>
<url-pattern>
/ResultHandler/*
</url-pattern>
</servlet-mapping>
</web-app>
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Server Side web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
<servlet>
<servlet-name>HandleCalc</servlet-name>
<servlet-class>CalculationHandler</servlet-class>
<load-on-startup/>
</servlet>
<servlet-mapping>
<servlet-name>HandleCalc</servlet-name>
<url-pattern>/CalculationHandler/*</url-pattern>
</servlet-mapping>
</web-app>
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ResultHolder.java
Browser
JAXM Servlet
ResultHandler
HTTPServlet
GetResultsAsHTML
Browser Two numbers
HTTP Servlet
DoCalculationServlet
Feedback to browser
right away
JAXM Provider
JAXM Servlet
CalculationHandler
JAXM Provider
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Server Side
CalculationHandler.java
// CalculationHandler.java -- Called by provider
//
-- Get values from message
//
-- Perform addition and send a message to provider
import java.net.*;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.*;
import javax.xml.messaging.*;
import javax.xml.soap.*;
import javax.activation.*;
import com.sun.xml.messaging.jaxm.ebxml.*;
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import org.apache.commons.logging.*;
import java.math.*;
public class CalculationHandler extends JAXMServlet implements
OnewayListener {
private static final boolean deBug = true;
private ProviderConnection serverProvider;
private MessageFactory messageFactory;
private String from;
private String to;
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public void init(ServletConfig config) throws ServletException {
super.init(config);
try {
// get a connection to the client provider
ProviderConnectionFactory providerFactory =
ProviderConnectionFactory.newInstance();
serverProvider = providerFactory.createConnection();
// Establish 'from' and 'to' URN's to be placed within the
// outgoing message.
// The provider must know how these names map to URL's
// via the Provider
// Administration tool.
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from = "urn:edu.cmu.andrew.mm6.serverProvider";
ProviderMetaData metaData = serverProvider.getMetaData();
String[] profiles = metaData.getSupportedProfiles();
boolean isProfileSupported = false;
for(int i = 0; i < profiles.length; i++)
if(profiles[i].equals("ebxml")) isProfileSupported = true;
if(isProfileSupported) {
// Build an EBXML style message factory
messageFactory = serverProvider.createMessageFactory("ebxml")
if(deBug)
System.out.println("Server side init complete with no problem");
}
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else
throw new ServletException("CalculationHandler” +
“ Profile problem" + new Date());
}
catch(Exception e) {
throw new ServletException(
"CalculationHandler Problems in init()" + e + new Date());
}
}
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public void onMessage(SOAPMessage reqMessage)
{
if(deBug) System.out.println("Hit onMessage() big time " +
new Date());
// Build SOAP document to return to the sender
try {
if(deBug) {
System.out.println("The following is the message received” +
“ by CalculationHandler onMessage");
reqMessage.writeTo(System.out);
}
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EbXMLMessageImpl resMessage = new
EbXMLMessageImpl(reqMessage);
to = "urn:edu.cmu.andrew.mm6.clientProvider";
resMessage.setSender(new Party(from));
resMessage.setReceiver(new Party(to));
Iterator i = resMessage.getAttachments();
AttachmentPart operand1 = (AttachmentPart) i.next();
AttachmentPart operand2 = (AttachmentPart) i.next();
String op1 = (String)(operand1.getContent());
String op2 = (String)(operand2.getContent());
BigInteger o1 = new BigInteger(op1);
BigInteger o2 = new BigInteger(op2);
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BigInteger result = o1.add(o2);
54
String answer = result.toString();
AttachmentPart answerPart = resMessage.createAttachmentPart();
answerPart.setContent(answer, "text/plain");
resMessage.addAttachmentPart(answerPart);
serverProvider.send(resMessage);
if(deBug) System.out.println(
"CalculationHandler: Message sent back to” +
“ clientProvider");
}
catch(IOException ioe) {
System.out.println("JAXM exception thrown " + ioe); }
catch(JAXMException je) {
System.out.println("JAXM exception thrown " + je); }
catch(SOAPException se) {
System.out.println("Soap exception thrown " + se); }
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}}
ResultHolder.java
Browser
JAXM Servlet
ResultHandler
HTTPServlet
GetResultsAsHTML
Browser Two numbers
HTTP Servlet
DoCalculationServlet
Feedback to browser
right away
JAXM Provider
JAXM Servlet
CalculationHandler
JAXM Provider
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HTTP Servlet
DoCalculationServlet
// DoCalculation.java -- Get values from client browser
//
-- Send SOAP request to ClientProvider Asynchronously
import java.net.*;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.*;
import javax.xml.messaging.*;
import javax.xml.soap.*;
import javax.activation.*;
import com.sun.xml.messaging.jaxm.ebxml.*;
import org.apache.commons.logging.*;
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// Normal servlet. Collects data from the browser, sends a SOAP message
// to a JAXM provider and does not wait for a response. Sends an HTML
// note of confirmation back to the browser.
public class DoCalculationServlet extends HttpServlet {
private ProviderConnection clientProvider;
private MessageFactory messageFactory;
private String from;
private String to;
private static final boolean deBug = true;
public void init(ServletConfig config) throws ServletException {
super.init(config);
if(deBug) System.out.println(
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Technologies
58
"Running at the top of
client
side html form init" + new Date());
try {
// get a connection to the client provider
ProviderConnectionFactory providerFactory =
ProviderConnectionFactory.newInstance();
clientProvider = providerFactory.createConnection();
// Establish 'from' and 'to' URN's to be placed within the
// outgoing message.
// The provider must know how these names map to
// URL's via the Provider
// Administration tool.
from = "urn:edu.cmu.andrew.mm6.clientProvider";
to = "urn:edu.cmu.andrew.mm6.serverProvider";
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ProviderMetaData metaData = clientProvider.getMetaData();
String[] profiles = metaData.getSupportedProfiles();
boolean isProfileSupported = false;
for(int i = 0; i < profiles.length; i++) {
if(profiles[i].equals("ebxml")) isProfileSupported = true;
}
if(isProfileSupported) {
// Build an EBXML style message factory
messageFactory = clientProvider.createMessageFactory(
"ebxml");
} else
throw new ServletException("Runtime Profile problem" +
new Date());
}
catch(Exception e) {
throw new ServletException("Run Time Problem in “ +
“DoCalculationServlet init()" + e + new Date());
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}}
public void doPost(HttpServletRequest req,
HttpServletResponse response)
throws ServletException,
IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String finalString = "";
String op1 = req.getParameter("op1");
String op2 = req.getParameter("op2");
// Build SOAP document to send to the provider
try {
EbXMLMessageImpl message = (EbXMLMessageImpl)
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61
message.setSender(new Party(from));
message.setReceiver(new Party(to));
AttachmentPart operand1 = message.createAttachmentPart();
operand1.setContent(op1, "text/plain");
AttachmentPart operand2 = message.createAttachmentPart();
operand2.setContent(op2, "text/plain");
message.addAttachmentPart(operand1);
message.addAttachmentPart(operand2);
clientProvider.send(message);
}
catch(JAXMException je) { System.out.println(
"JAXM exception thrown " + je); }
catch(SOAPException se) { System.out.println(
"Soap exception thrown " + se); }
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String docType = "<!DOCTYPE HTML PUBLIC \"//W3C//DTD"
+ " HTML 4.0 ";
docType += "Transitional//EN\">\n";
out.println(docType +
"<HTML>\n" +
"<HEAD><TITLE>Request Response" + "</TITLE>" +
"</HEAD>\n" +
"<BODY>\n" +
"<H2> Sent Calculation Request to Local Provider </H2>\n" +
"<H2>" + op1 + "+" + op2 + " will be computed</H2>\n" +
"</BODY></HTML>");
}
}
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ResultHolder.java
Browser
JAXM Servlet
ResultHandler
HTTPServlet
GetResultsAsHTML
Browser Two numbers
HTTP Servlet
DoCalculationServlet
Feedback to browser
right away
JAXM Provider
JAXM Servlet
CalculationHandler
JAXM Provider
Internet Technologies
64
JAXM Servlet ResultHandler
// ResultHandler.java -- Called by provider
//
-- Get result from message
//
-- Write result to a shared object or RDBMS
import java.net.*;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.*;
import javax.xml.messaging.*;
import javax.xml.soap.*;
import javax.activation.*;
import com.sun.xml.messaging.jaxm.ebxml.*;
import org.apache.commons.logging.*;
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import java.math.*;
65
public class ResultHandler extends JAXMServlet
implements OnewayListener {
private static final boolean deBug = true;
private ProviderConnection clientProvider;
private MessageFactory messageFactory;
String from, to;
public void init(ServletConfig config) throws ServletException {
super.init(config);
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try {
// get a connection to the client provider
ProviderConnectionFactory providerFactory =
ProviderConnectionFactory.newInstance();
clientProvider = providerFactory.createConnection();
// Establish 'from' and 'to' URN's to be placed within
// the outgoing message.
// The provider must know how these names map to URL's
// via the Provider
// Administration tool.
from = "urn:edu.cmu.andrew.mm6.clientProvider";
ProviderMetaData metaData = clientProvider.getMetaData();
String[] profiles = metaData.getSupportedProfiles();
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boolean isProfileSupported = false;
for(int i = 0; i < profiles.length; i++)
if(profiles[i].equals("ebxml")) isProfileSupported = true;
if(isProfileSupported) {
// Build an EBXML style message factory
messageFactory = clientProvider.createMessageFactory("ebxm
}
else
throw new ServletException("ResultHandler OnewayListener” +
“ Profile problem" + new Date());
}
catch(Exception e) {
throw new ServletException("ResultHandler OnewayListener”+
“ Problems in init()" + e + new Date()
}
}
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public void onMessage(SOAPMessage inMessage)
{
try {
if(deBug) { System.out.println("Message received from “ +
“ server appears now");
inMessage.writeTo(System.out);
}
// Read the data from the SOAP document
EbXMLMessageImpl resultMessage = new
EbXMLMessageImpl(inMessage);
Iterator i = resultMessage.getAttachments();
AttachmentPart operand1 = (AttachmentPart) i.next();
AttachmentPart operand2 = (AttachmentPart) i.next();
AttachmentPart result = (AttachmentPart) i.next();
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String op1 = (String)(operand1.getContent());
String op2 = (String)(operand2.getContent());
String res = (String)(result.getContent());
// Place the result in a shared object.
ResultHolder singleTon = ResultHolder.getInstance();
singleTon.setLastResult(op1 + " + " + op2 + " = " + res);
}
catch(Exception e) {
System.out.println("onMessage in ResultHandler exception " + e);
}
}
}
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70
ResultHolder.java
Browser
JAXM Servlet
ResultHandler
HTTPServlet
GetResultsAsHTML
Browser Two numbers
HTTP Servlet
DoCalculationServlet
Feedback to browser
right away
JAXM Provider
JAXM Servlet
CalculationHandler
JAXM Provider
Internet Technologies
71
ResultHolder.java
public class ResultHolder {
private String lastResult;
private static ResultHolder instance = new ResultHolder();
private ResultHolder() {
lastResult = "";
}
public static ResultHolder getInstance() { return instance; }
synchronized public String getLastResult() { return lastResult; }
synchronized public void setLastResult(String result) { lastResult
= result; }
synchronized public String toString() { return lastResult; }
}
Internet Technologies
72
ResultHolder.java
Browser
JAXM Servlet
ResultHandler
HTTPServlet
GetResultsAsHTML
Browser Two numbers
HTTP Servlet
DoCalculationServlet
Feedback to browser
right away
JAXM Provider
JAXM Servlet
CalculationHandler
JAXM Provider
Internet Technologies
73
GetResultsAsHTML
// GetResultAsHTML.java -- Get result from ResultHolder object
//
-- Send it back to client as HTML
import java.net.*;
import java.io.*;
import java.util.*;
import javax.servlet.http.*;
import javax.servlet.*;
public class GetResultAsHTML extends HttpServlet {
private static final boolean deBug = true;
public void init(ServletConfig config) throws ServletException {
super.init(config);Internet Technologies
74
}
public void doGet (HttpServletRequest req,
HttpServletResponse response)
throws ServletException,
IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String finalString = ResultHolder.getInstance().toString();
String docType = "<!DOCTYPE HTML PUBLIC \"//W3C//DTD"
+ " HTML 4.0 ";
docType += "Transitional//EN\">\n";
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out.println(docType +
"<HTML>\n" +
"<HEAD><TITLE>
GetResultAsHTML Response" + "</TITLE>" +
"</HEAD>\n" +
"<BODY>\n" +
"<H2> Most Recent Calculation </H2>\n" +
"<H2>" + finalString + "</H2>\n" +
"</BODY></HTML>");
}
}
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