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/**
*
*/
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);
}
}
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