diff options
Diffstat (limited to 'src/uk/org/ury/backend/handlers/LibraryRequestHandler.java')
| -rw-r--r-- | src/uk/org/ury/backend/handlers/LibraryRequestHandler.java | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/uk/org/ury/backend/handlers/LibraryRequestHandler.java b/src/uk/org/ury/backend/handlers/LibraryRequestHandler.java new file mode 100644 index 0000000..25423f6 --- /dev/null +++ b/src/uk/org/ury/backend/handlers/LibraryRequestHandler.java @@ -0,0 +1,189 @@ +/** + * + */ +package uk.org.ury.backend.handlers; + +import java.io.UnsupportedEncodingException; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Locale; +import java.util.Map; + +import org.apache.http.HttpRequest; +import org.apache.http.HttpResponse; +import org.apache.http.HttpStatus; +import org.apache.http.entity.StringEntity; +import org.apache.http.protocol.HTTP; +import org.apache.http.protocol.HttpContext; +import org.json.simple.JSONValue; + +import uk.org.ury.backend.database.DatabaseDriver; +import uk.org.ury.backend.database.UserClass; +import uk.org.ury.backend.database.exceptions.ConnectionFailureException; +import uk.org.ury.backend.database.exceptions.MissingCredentialsException; +import uk.org.ury.backend.database.exceptions.QueryFailureException; +import uk.org.ury.backend.server.AbstractRequestHandler; +import uk.org.ury.backend.server.Server; +import uk.org.ury.backend.server.exceptions.BadRequestException; +import uk.org.ury.backend.server.exceptions.HandleFailureException; +import uk.org.ury.backend.server.exceptions.HandlerNotFoundException; +import uk.org.ury.backend.server.exceptions.HandlerSetupFailureException; +import uk.org.ury.backend.server.exceptions.NotAHandlerException; +import uk.org.ury.backend.server.exceptions.UnknownFunctionException; +import uk.org.ury.common.library.LibraryUtils; +import uk.org.ury.common.library.exceptions.EmptySearchException; +import uk.org.ury.common.library.item.LibraryItem; +import uk.org.ury.common.protocol.Directive; +import uk.org.ury.common.protocol.Status; + +/** + * A request handler for library queries. + * + * @author Matt Windsor + */ +public class LibraryRequestHandler extends AbstractRequestHandler { + /** + * Construct a new LibraryRequestHandler. + * + * @param server + * The instance of the URY server responsible for the request. + * + * @param mount + * The directory to which this handler is to be mounted. + */ + public LibraryRequestHandler(Server server, String mount) { + super(server, mount); + } + + /** + * Perform a library search, populating the response list. + * + * @param parameters + * A key-value map of parameters supplied with the server + * request. Typically, the function parameter will detail the + * function that the request handler is expected to perform. + * + * @param response + * The response list to populate. + * + * @param server + * The server providing database resources. + * + * @throws HandleFailureException + * if an error occurs that thwarts the handling of the request. + */ + + private void doSearch(Map<String, String> parameters, + Map<String, Object> response, Server server) + throws HandleFailureException { + if (parameters.containsKey("search") == false) + throw new HandleFailureException("Search term is missing."); + else if (parameters.get("search") == null) + throw new HandleFailureException("Search term is null."); + + String search = parameters.get("search"); + DatabaseDriver dd = null; + + try { + dd = server.getDatabaseConnection(UserClass.READ_ONLY); + } catch (MissingCredentialsException e) { + throw new HandleFailureException(e.getMessage()); + } catch (ConnectionFailureException e) { + throw new HandleFailureException(e.getMessage()); + } + + try { + List<Map<String, String>> itemArray = new ArrayList<Map<String, String>>(); + + for (LibraryItem li : LibraryUtils.search(dd, search)) { + itemArray.add(li.asResponse()); + } + + response.put(Directive.ITEMS.toString(), itemArray); + } catch (QueryFailureException e) { + throw new HandleFailureException(e.getMessage()); + } catch (EmptySearchException e) { + throw new HandleFailureException(e.getMessage()); + } + } + + /** + * Handle a HTTP GET request. + * + * @param request + * The HTTP request. + * + * @param response + * The response that the handler will populate during the + * handling of the request. + * + * @param context + * The HTTP context. + * + * @throws HandlerNotFoundException + * if the client requested a request handler that could not be + * found on the class path. + * + * @throws HandlerSetupFailureException + * if the handler was found but could not be set up (eg does not + * implement appropriate interface or cannot be instantiated). + * + * @throws HandleFailureException + * if an appropriate handler was contacted, but it failed to + * process the request. + * + * @throws BadRequestException + * if the request was malformed or invalid. + * + * @throws NotAHandlerException + * if the class requested to handle the request is not a + * handler. + * + * @throws UnknownFunctionException + * if the request is for a path that does not correspond to one + * of this handler's functions. + */ + @Override + public void handleGet(HttpRequest request, HttpResponse response, + HttpContext context) throws HandlerNotFoundException, + HandlerSetupFailureException, HandleFailureException, + BadRequestException, NotAHandlerException, UnknownFunctionException { + String path; + String uri = request.getRequestLine().getUri(); + String query = getQueryString(uri); + + if (query == null) + path = uri.toLowerCase(Locale.ENGLISH); + else + path = uri.split("\\?" + query)[0].toLowerCase(Locale.ENGLISH); + + Map<String, Object> content = new HashMap<String, Object>(); + + if (path.equals("/library/tracks")) { + try { + doSearch(parseQueryString(query), content, server); + } catch (UnsupportedEncodingException e) { + throw new HandleFailureException(e.getMessage()); + } + } else { + throw new UnknownFunctionException(path); + } + + response.setStatusLine(request.getProtocolVersion(), HttpStatus.SC_OK, + "OK"); + + content.put(Directive.STATUS.toString(), Status.OK.toString()); + + StringEntity entity = null; + + try { + entity = new StringEntity(JSONValue.toJSONString(content)); + } catch (UnsupportedEncodingException e) { + throw new HandlerSetupFailureException(getClass().getName(), e); + } + + entity.setContentType(HTTP.PLAIN_TEXT_TYPE); + response.setEntity(entity); + } +} |