Science With the Virtual Observatory 2006 Summer School

Create a keywordsearch Tool: Hints

Our stub function looks like this:

public static SimpleResource[] keywordSearch(String keywords) 
     throws ServiceException, RemoteException 
{
    String query = "";    //
    String keyword;

    StringTokenizer st = new StringTokenizer(keywords);
    while (st.hasMoreTokens()) {
        keyword = st.nextToken();

        // add in our constraints to the query

    }

    System.err.println("Registry query: " + query);                 //

    // submit our query

    return null;
}

We can start by setting our base query. Change:

    String query = "";

to:

    String query = "ServiceType like '%CONE%'";

The while loop that is already in the stub parses out each word and sets it to keyword. For each keyword, we want it to match any of a selected set of text metadata. The constraint for each word then might look something like this, place just after keyword is set:

String constraint = "Title like '%" + keyword + "%' or " +
    "ShortName like '%" + keyword + "' or "

You could add any other attributes (e.g. Description, Subject, etc.).

In this implementation, we will require that all given keywords be matched somewhere. So we add each keyword constraint to the query with the following:

query += " and (" + constraint + ")"; 

Now we're ready to submit the query. This is done in exactly the same way we did it in the search() method, so we can just cut and paste the remaining code in (replacing the return null):

  // get a registry service object
  Registry regService = new RegistryLocator();

  // get an interface object that can accept our query.
  RegistrySoap regInterface = regService.getRegistrySoap();

  // Now submit the query
  ArrayOfSimpleResource results = regInterface.queryRegistry(query);

  // return all of the results
  return results.getSimpleResource();

You are done.

The NVO Summer School is made possible through the support of the National Science Foundation and the National Aeronautics and Space Administration.