code: public static SortedSet<String> getCurrentPDBIds() throws IOException {
  
  		SortedSet<String> allPDBs = new TreeSet<String>();
  		String serverName = System.getProperty(PDB_SERVER_PROPERTY);
  
  		if ( serverName == null)
  			serverName = DEFAULT_PDB_SERVER;
  		else
  			logger.info(String.format("Got System property %s=%s",PDB_SERVER_PROPERTY,serverName));
  
  		// Build REST query URL
  
  		String urlStr = String.format("http://%s/pdb/rest/getCurrent",serverName);
  		URL u = new URL(urlStr);
  
  		InputStream stream = URLConnectionTools.getInputStream(u, 60000);
  
  		if (stream != null) {
  			BufferedReader reader = new BufferedReader(
  					new InputStreamReader(stream));
  
  			String line = null;
  
  			while ((line = reader.readLine()) != null) {
  				int index = line.lastIndexOf("structureId=");
  				if (index > 0) {
  					allPDBs.add(line.substring(index + 13, index + 17));
  				}
  			}
  		}
  		return allPDBs;
  
  	}
docs: Returns a list of current PDB IDs
  
  @return a list of PDB IDs, or null if a problem occurred