Web Service Versioning and Deprecation by Jeff Kenyon
WSJ Vol 03 Issue 2 - pg.22

	


Listing 1: Web service supporting a getVersion message
<%@ WebService Language="C#" Class="SomeService" %>
using System.Web.Services;
public class SomeService {
     [ WebMethod ]
     public Version getVersion() {
	Version result = new Version();	
	result.setMajor(1);
	result.setMinor(2);
	result.setPatch(3);
        return result;
     }
}


public class Version {
	private int major = 0;
	private int minor = 0;
	private int patch = 0;
	public void setMajor(int x) {
		major = x;
	}
	public int getMajor() {
		return major;
	}
	public void setMinor(int x) {
		minor = x;
	}
	public int getMinor() {
		return minor;
	}
	public void setPatch(int x) {
		patch = x;
	}
	public int getPatch() {
		return patch;
	}
}

Listing 2: Performing the wider search
UDDIProxy proxy = new UDDIProxy();
Collection results = new TreeSet(new VersionCompare());

// Find all businesses 

Vector businessInfoVector = null;         
BusinessList bl = 
    proxy.find_business("%", new FindQualifiers(), 0);
        
try {
     businessInfoVector =
        bl.getBusinessInfos().getBusinessInfoVector(); 
} catch (NullPointerException e) {
     // do nothing; let the function return an empty collection
}
           
// Find all services

if (businessInfoVector != null) {
    for (int i = 0; i < businessInfoVector.size(); i++) {
        BusinessInfo businessInfo = 
            (BusinessInfo)businessInfoVector.elementAt(i);

        // Retrieve list of service
        Vector serviceInfos;
        try {
             serviceInfos = 
                businessInfo.getServiceInfos().getServiceInfoVector();
        } catch (NullPointerException e) {
            // may not have any service details
            continue;
        }
               
        Enumeration enum1 = serviceInfos.elements();
        while (enum1.hasMoreElements()) {
                   
            ServiceInfo si = (ServiceInfo)enum1.nextElement();

            // set up tModel bag
            Vector vTModels = new Vector();
            vTModels.add(tModelKey);

            TModelBag tmBag = new TModelBag(vTModels);

            // Find all bindings matching tModel

            BindingDetail bd = 
                proxy.find_binding(new FindQualifiers(),
                                   si.getServiceKey(),
                                   tmBag,
                                   0);

            Vector vBindings = bd.getBindingTemplateVector();
            Enumeration enumBindings = vBindings.elements();
            while (enumBindings.hasMoreElements()) {
                BindingTemplate bt = 
                    (BindingTemplate) enumBindings.nextElement();
		    // add to TreeSet
		    results.add(new BindingObj(bt));
            }
        }
    }
} 
       
return results;

Listing 3: Deserialize the structure
SOAPMappingRegistry smr =
    new SOAPMappingRegistry(Constants.NS_URI_2001_SCHEMA_XSD);
BeanSerializer beanSer = new BeanSerializer();
IntDeserializer id = new IntDeserializer();
smr.mapTypes(Constants.NS_URI_SOAP_ENC,
		     new QName("http://tempuri.org/","getVersionResult"),
		     Version.class, beanSer, beanSer);
smr.mapTypes(Constants.NS_URI_SOAP_ENC,
		     new QName("http://tempuri.org/","major"),null, null, id);
smr.mapTypes(Constants.NS_URI_SOAP_ENC,
		     new QName("http://tempuri.org/","minor"),null, null, id);
smr.mapTypes(Constants.NS_URI_SOAP_ENC,
		     new QName("http://tempuri.org/","patch"),null, null, id);
call.setSOAPMappingRegistry(smr);

Listing 4: Java code to retrive a tModel object.
UDDIProxy proxy = new UDDIProxy();

try {       
     // Point to UDDI server
     proxy.setInquiryURL
         ("http://localhost/uddi/api/inquire.asmx");
} catch (Exception e) {
     e.printStackTrace();
}

// Task 1A: Retrieve tModel identifiers
Vector vTM = new Vector();
try {
    vTM =
	proxy.get_tModelDetail(tModelKey).getTModelVector();
} catch (Exception e) {
    // Proxy threw a SOAP or UDDI error.
    // Throw fatal exception. 
    System.err.println("UDDI Registry access error: " + e);
}

// take the TModel off the Vector.
TModel tm = null;
if (vTM.size() > 0) {
    tm = (TModel) vTM.elementAt(0);
} else {
    // No TModel returned. Hmmm. That shouldn't happen.  
    // Exit with empty collection
    return bindings;
}

Listing 5: identifierBag.
// Grab its identifiers
String deprecated = null;
String deprecatedLink = null;
String deprecatedMsg = null;

Enumeration enumIdentifiers = 
    tm.getIdentifierBag().getKeyedReferenceVector().elements();
while (enumIdentifiers.hasMoreElements()) {
    KeyedReference kr = (KeyedReference)enumIdentifiers.nextElement();
    if (kr.getKeyName().equals("DEPRECATED")) {
	deprecated = kr.getKeyValue();	
    } else if (kr.getKeyName().equals("DEPRECATED_MSG")) {
	deprecatedMsg = kr.getKeyValue();	
    } else if (kr.getKeyName().equals("DEPRECATED_LINK")) {
	deprecatedLink = kr.getKeyValue();	
    }
}

Listing 6: Generated message.
if (!(deprecated.equals(null))) {
    // convert deprecated value to date
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
    Date today = new Date();
    Date deprecationDate = new Date();
    try {
	deprecationDate = formatter.parse(deprecated);
    } catch (ParseException e) {
	// Unparseable date string: set to 3000/12/31
	try {
	    deprecationDate = formatter.parse("3000/12/31");
	} catch (ParseException e1) {
	    System.err.println("Very serious parsing problem: " + e1);
	}
    }

    if (deprecationDate.after(today))
	{
	    // value >= today, exception
	    // include values of DEPRECATED_MSG and DEPRECATED-LINK in
	    // any exception.
	    System.err.println
		("TModel will be formally deprecated after " + 
		 formatter.format(deprecationDate) +
		 " (" + deprecatedMsg + " [" + 
		 deprecatedLink + "]).");
	} else if (deprecationDate.equals(today) || 
		   deprecationDate.before(today)) {
	    // value < today, fatal exception
	    // include values of DEPRECATED_MSG and DEPRECATED-LINK
	    throw new WebServiceDeprecationException
		("TModel has been formally deprecated as of " + 
		 formatter.format(deprecationDate) +
		 " (" + deprecatedMsg + " [" + 
		 deprecatedLink + "]).");
	}
}