How to open a network dataset

// For example, path = @"C:\myData\myfGDB.gdb".
public static IWorkspace fileGdbWorkspaceFromPath(String path)throws
    AutomationException, IOException{
    IWorkspaceFactory workspaceFactory = new FileGDBWorkspaceFactory();
    return workspaceFactory.openFromFile(path, 0);
}

// For example, path = @"C:\myData\mySDC".
public static IWorkspace sdcWorkspaceFromPath(String path)throws AutomationException,
    IOException{
    IWorkspaceFactory workspaceFactory = new SDCWorkspaceFactory();
    return workspaceFactory.openFromFile(path, 0);
}

public static INetworkDataset openNetworkDataset(IWorkspace networkDatasetWorkspace,
    String networkDatasetName, String featureDatasetName)throws AutomationException,
    IOException{
    // Shapefile and SDC network datasets will not have a feature dataset, 
    // so pass in the featureDatasetName as an empty string for those types.
    if (networkDatasetWorkspace == null || networkDatasetName == "")
        return null;
    // Get the IDatasetContainer based on the workspace type.
    IDatasetContainer3 datasetContainer3 = null;
    switch (networkDatasetWorkspace.getType()){
        // Example: FileSystemWorkspaces include SDC and shapefile.
        case esriWorkspaceType.esriFileSystemWorkspace:
            IWorkspaceExtensionManager workspaceExtensionManager = 
                (IWorkspaceExtensionManager)networkDatasetWorkspace;
            UID networkID = new UID();
            networkID.setValue("esriGeoDatabase.NetworkDatasetWorkspaceExtension");
            IWorkspaceExtension workspaceExtension =
                workspaceExtensionManager.findExtension(networkID);
            datasetContainer3 = new IDatasetContainer3Proxy(workspaceExtension);
            break;
            // Example: LocalDatabaseWorkspaces can be personal geodatabases and file geodatabases.
            // An example RemoteDatabaseWorkspace is an ArcSDE geodatabase.
            // Both LocalDatabaseWorkspace and RemoteDatabaseWorkspace network datasets are 
            // opened the same way.
        case esriWorkspaceType.esriLocalDatabaseWorkspace:
        case esriWorkspaceType.esriRemoteDatabaseWorkspace:
            if (featureDatasetName == null)
                return null;
            IFeatureWorkspace featureWorkspace = (IFeatureWorkspace)
                networkDatasetWorkspace;
            IFeatureDataset featureDataset = featureWorkspace.openFeatureDataset
                (featureDatasetName);
            IFeatureDatasetExtensionContainer featureDatasetExtensionContainer = new
                IFeatureDatasetExtensionContainerProxy(featureDataset);
            IFeatureDatasetExtension featureDatasetExtension =
                featureDatasetExtensionContainer.findExtension
                (esriDatasetType.esriDTNetworkDataset);
            datasetContainer3 = new IDatasetContainer3Proxy(featureDatasetExtension);
            break;
    }
    if (datasetContainer3 == null)
        return null;
    // Use the container to open the network dataset.
    IDataset dataset = datasetContainer3.getDatasetByName
        (esriDatasetType.esriDTNetworkDataset, networkDatasetName);
    INetworkDataset networkDataset = new INetworkDatasetProxy(dataset);
    // Some Network Analyst methods, such as INASolver.Bind, require an IDENetworkDataset.
    // You can access the DataElement from the network dataset via the IDatasetComponent interface.
    IDatasetComponent datasetComponent = new IDatasetComponentProxy(networkDataset);
    IDENetworkDataset deNetworkDataset = (IDENetworkDataset)
        datasetComponent.getDataElement();
    return networkDataset;
}