Accessing SWbemObject Object Properties using J-Interop Library - windows

Question

I am very new to J-Interop Library and WMI. I was just playing around with the following sample code from j-interop samples (MSWMI, which deals with WMI Communication).
package org.jinterop.dcom.test;
import java.net.UnknownHostException;
import java.util.logging.Level;
import org.jinterop.dcom.common.IJIUnreferenced;
import org.jinterop.dcom.common.JIException;
import org.jinterop.dcom.common.JISystem;
import org.jinterop.dcom.core.IJIComObject;
import org.jinterop.dcom.core.JIArray;
import org.jinterop.dcom.core.JICallBuilder;
import org.jinterop.dcom.core.JIComServer;
import org.jinterop.dcom.core.JIFlags;
import org.jinterop.dcom.core.JIProgId;
import org.jinterop.dcom.core.JISession;
import org.jinterop.dcom.core.JIString;
import org.jinterop.dcom.core.JIVariant;
import org.jinterop.dcom.impls.JIObjectFactory;
import org.jinterop.dcom.impls.automation.IJIDispatch;
import org.jinterop.dcom.impls.automation.IJIEnumVariant;
public class MSWMI {
private JIComServer comStub = null;
private IJIComObject comObject = null;
private IJIDispatch dispatch = null;
private String address = null;
private JISession session = null;
public MSWMI(String address, String[] args) throws JIException, UnknownHostException
{
this.address = address;
session = JISession.createSession(args[1],args[2],args[3]);
session.useSessionSecurity(true);
session.setGlobalSocketTimeout(5000);
comStub = new JIComServer(JIProgId.valueOf("WbemScripting.SWbemLocator"),address,session);
IJIComObject unknown = comStub.createInstance();
comObject = (IJIComObject)unknown.queryInterface("76A6415B-CB41-11d1-8B02-00600806D9B6");//ISWbemLocator
//This will obtain the dispatch interface
dispatch = (IJIDispatch)JIObjectFactory.narrowObject(comObject.queryInterface(IJIDispatch.IID));
}
public void performOp() throws JIException, InterruptedException
{
System.gc();
JIVariant results[] = dispatch.callMethodA("ConnectServer",new Object[]{new JIString(address),JIVariant.OPTIONAL_PARAM(),JIVariant.OPTIONAL_PARAM(),JIVariant.OPTIONAL_PARAM()
,JIVariant.OPTIONAL_PARAM(),JIVariant.OPTIONAL_PARAM(),new Integer(0),JIVariant.OPTIONAL_PARAM()});
//using the dispatch results above you can use the "ConnectServer" api to retrieve a pointer to IJIDispatch
//of ISWbemServices
//OR
//Make a direct call like below , in this case you would get back an interface pointer to ISWbemServices , NOT to it's IDispatch
JICallBuilder callObject = new JICallBuilder();
callObject.addInParamAsString(address,JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsString("",JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsString("",JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsString("",JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsString("",JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsString("",JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsInt(0,JIFlags.FLAG_NULL);
callObject.addInParamAsPointer(null,JIFlags.FLAG_NULL);
callObject.setOpnum(0);
callObject.addOutParamAsType(IJIComObject.class,JIFlags.FLAG_NULL);
IJIComObject wbemServices = JIObjectFactory.narrowObject((IJIComObject)((Object[])comObject.call(callObject))[0]);
wbemServices.setInstanceLevelSocketTimeout(1000);
wbemServices.registerUnreferencedHandler(new IJIUnreferenced(){
public void unReferenced()
{
System.out.println("wbemServices unreferenced... ");
}
});
//Lets have a look at both.
IJIDispatch wbemServices_dispatch = (IJIDispatch)JIObjectFactory.narrowObject((results[0]).getObjectAsComObject());
results = wbemServices_dispatch.callMethodA("InstancesOf", new Object[]{new JIString("Win32_Process"), new Integer(0), JIVariant.OPTIONAL_PARAM()});
IJIDispatch wbemObjectSet_dispatch = (IJIDispatch)JIObjectFactory.narrowObject((results[0]).getObjectAsComObject());
JIVariant variant = wbemObjectSet_dispatch.get("_NewEnum");
IJIComObject object2 = variant.getObjectAsComObject();
System.out.println(object2.isDispatchSupported());
System.out.println(object2.isDispatchSupported());
object2.registerUnreferencedHandler(new IJIUnreferenced(){
public void unReferenced()
{
System.out.println("object2 unreferenced...");
}
});
IJIEnumVariant enumVARIANT = (IJIEnumVariant)JIObjectFactory.narrowObject(object2.queryInterface(IJIEnumVariant.IID));
//This will return back a dispatch of ISWbemObjectSet
//OR
//It returns back the pointer to ISWbemObjectSet
callObject = new JICallBuilder();
callObject.addInParamAsString("Win32_Process",JIFlags.FLAG_REPRESENTATION_STRING_BSTR);
callObject.addInParamAsInt(0,JIFlags.FLAG_NULL);
callObject.addInParamAsPointer(null,JIFlags.FLAG_NULL);
callObject.setOpnum(4);
callObject.addOutParamAsType(IJIComObject.class,JIFlags.FLAG_NULL);
IJIComObject wbemObjectSet = JIObjectFactory.narrowObject((IJIComObject)((Object[])wbemServices.call(callObject))[0]);
//okay seen enough of the other usage, lets just stick to disptach, it's lot simpler
JIVariant Count = wbemObjectSet_dispatch.get("Count");
int count = Count.getObjectAsInt();
for (int i = 0; i < count; i++)
{
Object[] values = enumVARIANT.next(1);
JIArray array = (JIArray)values[0];
Object[] arrayObj = (Object[])array.getArrayInstance();
for (int j = 0; j < arrayObj.length; j++)
{
IJIDispatch wbemObject_dispatch = (IJIDispatch)JIObjectFactory.narrowObject(((JIVariant)arrayObj[j]).getObjectAsComObject());
JIVariant variant2 = (JIVariant)(wbemObject_dispatch.callMethodA("GetObjectText_",new Object[]{new Integer(1)}))[0];
System.out.println(variant2.getObjectAsString().getString());
System.out.println("++++++++++++++++++++++++++++++++++++++++++++++++++++++++++");
}
}
}
private void killme() throws JIException
{
JISession.destroySession(session);
}
public static void main(String[] args) {
try {
if (args.length < 4)
{
System.out.println("Please provide address domain username password");
return;
}
JISystem.getLogger().setLevel(Level.INFO);
JISystem.setInBuiltLogHandler(false);
JISystem.setAutoRegisteration(true);
MSWMI test = new MSWMI(args[0],args);
for (int i = 0 ; i < 100; i++)
{
System.out.println("Index i: " + i);
test.performOp();
}
test.killme();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
I understand that the following line of code calls the method "GetObjectText_" of the SWbemObject Object and we can see all the properties of the class instance.
JIVariant variant2 = (JIVariant)(wbemObject_dispatch.callMethodA("GetObjectText_",new Object[]{new Integer(1)}))[0];
What I wish to find out is, what should I do if I just need to retrieve a single property value, for example, if all I wanted was to retrieve the "InstallDate" property of the "Win32_Process" Class, what method would I call or how to access a particular property if I knew the property name I wish to access.
Any help on this topic would be great. Thanks a lot!!

Answer 1

You could access a property with the following code:
JIVariant variant2 = (JIVariant)(wbemObject_dispatch.get("Caption"));
This replaces the line:
JIVariant variant2 = (JIVariant)(wbemObject_dispatch.callMethodA("GetObjectText_",new Object[]{new Integer(1)}))[0];
The “InstallDate” properties were all empty so I use the “Caption”.