One of steps is that we should be able to programatically access bugzilla and do some operations with the bug. Probably search for a list of bugs and verify the comments etc.. It turns out Bugzilla only supports XML-RPC and JSON-RPC protocols, where as XML-RPC being the stable one we went ahead and picked it.
Since its the first time I'm going to use XML-RPC, I did some research on net about it and found that there's one cool API framework available from apache, its called 'The Apache XML-RPC client'.
Just like any other API from apache, it came with loads of documentation and Javadocs.., a big thanks to those geeks for maintaining code.
Coming back to problem at hand, All I wanted to do was to access bugzilla and login and do some operations in it with a list of bugs. Following is the code snippet that I simply copied and modified from the apache's examples for XML-RPC client.
import java.net.MalformedURLException;
import java.net.URL;
import org.apache.xmlrpc.XmlRpcException;
import org.apache.xmlrpc.client.XmlRpcClient;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;
public class Bugzilla {
public static void main(String[] args) throws MalformedURLException, XmlRpcException {
XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
config.setServerURL(new URL("http://bug-tracker.yyyy.com/Bugzilla/xmlrpc.cgi"));
XmlRpcClient client = new XmlRpcClient();
client.setConfig(config);
Object[] params = new Object[]{"xxx@yyy.com", "password"};
Object result = client.execute("User.login", params);
System.out.println("Result = "+result);
}
}
When i ran this, it started throwing this exception..
The error message is confusing and doesn't really point me to the root cause.
Exception in thread "main" java.lang.ClassCastException: java.lang.String
at org.apache.xmlrpc.parser.XmlRpcResponseParser.addResult(XmlRpcResponseParser.java:61)
at org.apache.xmlrpc.parser.RecursiveTypeParserImpl.endValueTag(RecursiveTypeParserImpl.java:78)
at org.apache.xmlrpc.parser.XmlRpcResponseParser.endElement(XmlRpcResponseParser.java:186)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:633)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanEndElement(XMLNSDocumentScannerImpl.java:719)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(XMLDocumentFragmentScannerImpl.java:1685)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:368)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:834)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:764)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:148)
at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1242)
at org.apache.xmlrpc.client.XmlRpcStreamTransport.readResponse(XmlRpcStreamTransport.java:186)
at org.apache.xmlrpc.client.XmlRpcStreamTransport.sendRequest(XmlRpcStreamTransport.java:156)
at org.apache.xmlrpc.client.XmlRpcHttpTransport.sendRequest(XmlRpcHttpTransport.java:115)
at org.apache.xmlrpc.client.XmlRpcSunHttpTransport.sendRequest(XmlRpcSunHttpTransport.java:69)
at org.apache.xmlrpc.client.XmlRpcClientWorker.execute(XmlRpcClientWorker.java:56)
at org.apache.xmlrpc.client.XmlRpcClient.execute(XmlRpcClient.java:167)
at org.apache.xmlrpc.client.XmlRpcClient.execute(XmlRpcClient.java:137)
at org.apache.xmlrpc.client.XmlRpcClient.execute(XmlRpcClient.java:126)
at Bugzilla.main(Bugzilla.java:21)
After an hour of search, found the mystery with the error above. It turns out Bugzilla follows certain rules with the XML-RPC implementation.
- All the parameters that are passed to Bugzilla must be a named parameter.
- All the parameters are treated as 'struct' tag by Bugzilla, so we must pass all the parameters as keys and values in a HashMap.
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import org.apache.xmlrpc.XmlRpcException;
import org.apache.xmlrpc.client.XmlRpcClient;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;
public class Bugzilla {
public static void main(String[] args) throws MalformedURLException, XmlRpcException {
XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
config.setServerURL(new URL("http://bug-tracker.yyyy.com/Bugzilla/xmlrpc.cgi"));
XmlRpcClient client = new XmlRpcClient();
client.setConfig(config);
Map map = new HashMap();
map.put("login","xxxx@yyyy.com");
map.put("password","password");
Map result = (Map) client.execute("User.login", new Object[]{map});
System.out.println("Result = "+result);
}
}
The response from bugzilla is again a Map object, so I had to cast it to make sure I can access elements in it.
Now comes the next hurdle. Bugzilla's XML-RPC apis also assume that the client maintains the session with the server using cookies. The problem now is to figure out a way to do that with the apache XML-RPC client APIs. I'm going to write about it in my next blog post.
