UseCCPPOrUAProf
This technique gives a possible implementation for the CategoryBpContext using JSR-188. The idea is to capture client's profile information (CC/PP or, more likely, UAProf) so the context of the client is known in order to server appropriate content. The idea of the example shown below is a servlet to return to the client a list of the attributes and values in profile information as declared by the client via HTTP GET request's headers. Most of desktop user agents do not provide CC/PP and/or UAProf information so the example should be tested at client side by a mobile device or an emulator.
Pre-requisites:
- A servlet container
- JSR-188 API
Implementation Steps:
- Have a servlet container running.
- JSR-188 API must be installed and accessible for our application (it includes XML files appearing in sample code).
- Create an application implemented by a servlet with the following code:
Example:
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URL;
import java.util.Iterator;
import java.util.Set;
import javax.ccpp.Attribute;
import javax.ccpp.Profile;
import javax.ccpp.ProfileFactory;
import javax.ccpp.ValidationMode;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.sun.ccpp.DescriptionManager;
import com.sun.ccpp.ProfileFactoryImpl;
public class JavaCCPPExample extends javax.servlet.http.HttpServlet implements
javax.servlet.Servlet
{
public JavaCCPPExample()
{
super();
}
// Servlet's initialization method where the schema of the vocabulary is set
// and all vocabularies to be processed by are configured. This configuration
// process is very important for the servlet to properly work
public void init(ServletConfig config)
{
ServletContext context = null;
String VocabularyPath = "\\Vocabularies\\";
DescriptionManager dm = null;
URL vocab = null;
URL schema = null;
// Get the context of the servlet to get resources later
context = config.getServletContext();
try
{
// Set the schema followed by vocabularies
schema = context.getResource(VocabularyPath + "vocabulary.xsd");
DescriptionManager.setSchema(schema.openStream());
// Get an instance of the Description Manager in order to add several
// vocabularies
dm = DescriptionManager.getInstance();
// Add a set of vocabularies which will allow proper processing
// of CC/PP and UAProf profiles
vocab = context.getResource(VocabularyPath + "universalvocab.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "example.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-19991014.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20000405.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20000405a.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20000405b.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010111.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010330.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010330a.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010330b.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010430.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010430a.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20010430b.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20020710.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20020710a.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20020710b.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20021212.xml");
dm.addVocabulary(vocab.openStream());
vocab = context.getResource(VocabularyPath + "ccppschema-20030226.xml");
dm.addVocabulary(vocab.openStream());
}
catch (Exception e)
{
e.printStackTrace();
}
}
// Method to serve GET requests made from the client and get a list of client's
// capabilities (as long as it publishes its CC/PP and/or UAProf profile)
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
// Object to access profile factory (see JSR-188 doc)
ProfileFactory pf = null;
// Object created for profile access
Profile profile = null;
// Set MIME type for content returned by the servlet
response.setContentType("text/html");
// Get a "PrintWriter" object that will be used to create (X)HTML code returned
// to the client
PrintWriter out = response.getWriter();
out.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
out.print("<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\" ");
out.println("\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">");
out.println("<html xmlns=\"http://www.w3.org/1999/xhtml\">");
out.println("<head>");
out.println("<title>Servlet to process CC/PP over HTTP</title>");
out.println("</head>");
out.println("<body>");
// Get an instance of a profile factory
pf = ProfileFactoryImpl.getInstance();
// Try to discover the profile declared by the client in HTTP request.
// Validation mode is deactivated in order to be able to process most of the profiles.
// Setting weak or strong validation modes might lead to some profiles not being
// processed or not all the atributes being listed
profile = pf.newProfile(request,ValidationMode.VALIDATIONMODE_NONE);
//profile = pf.newProfile(request, ValidationMode.VALIDATIONMODE_WEAK);
//profile = pf.newProfile(request, ValidationMode.VALIDATIONMODE_STRONG);
// If profile is null then client has not declared any profile or profile is wrong
if (profile == null)
{
out.println("<p>Client has not declared CC/PP and/or UAProf information</p>");
}
// Otherwise profile exists and is OK
else
{
// Get the set of attributes declared
Set allAttributes = profile.getAttributes();
Iterator attrib = allAttributes.iterator();
// Iterate on the set of attributes in order to get access to them attributes
// as a list of pairs "Attribute: Value"
while (attrib.hasNext())
{
Attribute attribute = (Attribute) attrib.next();
Object value = attribute.getValue();
out.println("<p>" + attribute.getName() + " = " + value + "</p>");
}
}
out.println("</body>");
out.println("</html>");
}
}
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