# resource handling and loading for events

2026-10-10 14:20:55 +00:00 · 2013-01-30 18:43:37 +01:00
1 parent 3de188f98b
commit 594acb1743
@@ -7,6 +7,15 @@ import com.sap.sailing.server.gateway.deserialization.JsonDeserializationExcepti

 public class Helpers {
 	
+	public static JSONArray toJSONArraySafe(Object object)
+			throws JsonDeserializationException {
+		if (object instanceof JSONArray) {
+			return (JSONArray) object;
+		}
+		throw new JsonDeserializationException(
+				String.format("Expected a JSONArray, got %s.", object.getClass().getName()));
+	}
+	
 	public static JSONObject toJSONObjectSafe(Object object)
 			throws JsonDeserializationException {
 		if (object instanceof JSONObject) {
@@ -1,13 +1,23 @@
 package com.sap.sailing.racecommittee.app.data;

+import java.net.URI;
+import java.util.Collection;
+
 import android.content.Context;

 import com.sap.sailing.domain.base.Event;
 import com.sap.sailing.racecommittee.app.data.clients.EventsLoadClient;
 import com.sap.sailing.racecommittee.app.data.handlers.DataHandler;
+import com.sap.sailing.racecommittee.app.data.handlers.EventsDataHandler;
+import com.sap.sailing.racecommittee.app.data.loaders.DataLoader;
+import com.sap.sailing.racecommittee.app.data.parsers.DataParser;
+import com.sap.sailing.racecommittee.app.data.parsers.EventsDataParser;
+import com.sap.sailing.server.gateway.deserialization.impl.CourseAreaJsonDeserializer;
+import com.sap.sailing.server.gateway.deserialization.impl.EventJsonDeserializer;
+import com.sap.sailing.server.gateway.deserialization.impl.VenueJsonDeserializer;

 /**
- * Enables accessing of all data
+ * Enables accessing of data.
 */
 public class DataManager {
 	
@@ -32,8 +42,18 @@ public class DataManager {
 	}

 	protected void loadEvents(EventsLoadClient client) {
-		// TODO Auto-generated method stub
-		DataHandler<Event> handler = null;
+		DataParser<Collection<Event>> parser = new EventsDataParser(
+				new EventJsonDeserializer(
+					new VenueJsonDeserializer(
+							new CourseAreaJsonDeserializer())));
+		DataHandler<Collection<Event>> handler = new EventsDataHandler(this, client);
+		
+		DataLoader<Collection<Event>> loader = new DataLoader<Collection<Event>>(
+				context, 
+				URI.create("http://10.0.2.2:8888/sailingserver/rc/events"), 
+				parser, 
+				handler);
+		loader.startLoading();
 	}
 	
 	
@@ -4,6 +4,6 @@ import java.util.Collection;

 import com.sap.sailing.domain.base.Event;

-public interface EventsLoadClient extends LoadClient<Event> {
+public interface EventsLoadClient extends LoadClient<Collection<Event>> {
 	public void onEventsLoaded(Collection<Event> events);
 }
@@ -0,0 +1,22 @@
+package com.sap.sailing.racecommittee.app.data.handlers;
+
+import java.util.Collection;
+
+import com.sap.sailing.domain.base.Event;
+import com.sap.sailing.racecommittee.app.data.DataManager;
+import com.sap.sailing.racecommittee.app.data.clients.EventsLoadClient;
+
+public class EventsDataHandler extends DataHandler<Collection<Event>> {
+
+	public EventsDataHandler(DataManager manager, EventsLoadClient client) {
+		super(manager, client);
+	}
+	
+	@Override
+	public void onLoaded(Collection<Event> data) {
+		super.onLoaded(data);
+		// TODO: add to manager!
+		((EventsLoadClient)client).onEventsLoaded(data);
+	}
+
+}
@@ -1,16 +0,0 @@
-package com.sap.sailing.racecommittee.app.data.http;
-
-import java.io.IOException;
-
-import org.apache.http.HttpResponse;
-import org.apache.http.client.ClientProtocolException;
-import org.apache.http.client.methods.HttpDelete;
-
-public class DeleteHttpRequest extends HttpRequest {
-
-	public HttpResponse delete(String service) throws ClientProtocolException, IOException {
-		HttpDelete delete = new HttpDelete(service);
-		HttpResponse response = executeRequest(delete, "DELETE request");
-		return response;
-	}
-}
@@ -1,29 +1,20 @@
 package com.sap.sailing.racecommittee.app.data.http;

 import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;

 import org.apache.http.HttpEntity;
 import org.apache.http.HttpResponse;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.methods.HttpRequestBase;
-import org.codehaus.jackson.JsonGenerationException;
-import org.codehaus.jackson.JsonParser;
-import org.codehaus.jackson.map.JsonMappingException;
-import org.codehaus.jackson.map.ObjectMapper;
-import org.codehaus.jackson.type.TypeReference;

-public class GetHttpRequest<T> extends HttpRequest {
+public class GetHttpRequest extends HttpRequest {

-	public T get(String url, TypeReference<?> typeref)
-			throws JsonGenerationException, JsonMappingException, IOException {
-		ObjectMapper mapper = new ObjectMapper();
-		/*mapper = */mapper
-				.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true)
-				.configure(org.codehaus.jackson.map.DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
-		
-		HttpRequestBase get = new HttpGet(url);
-		HttpResponse response = executeRequest(get, "GET request");
+	public InputStream get(URI requestUri) throws IOException {
+		HttpRequestBase get = new HttpGet(requestUri);
+		HttpResponse response = executeRequest(get);
 		HttpEntity entity = response.getEntity();
-		return mapper.readValue(entity.getContent(), typeref);
+		return entity.getContent();
 	}
 }
@@ -5,7 +5,6 @@ import java.io.IOException;
 import org.apache.http.HttpResponse;
 import org.apache.http.HttpStatus;
 import org.apache.http.StatusLine;
-import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.methods.HttpRequestBase;
 import org.apache.http.impl.client.DefaultHttpClient;
@@ -19,19 +18,19 @@ public abstract class HttpRequest {
 	private final static int lowestOkCode = HttpStatus.SC_OK;
 	private final static int lowestRedirectCode = HttpStatus.SC_MULTIPLE_CHOICES; 
 	
-	private static void validateHttpResponse(HttpResponse response) {
+	private static void validateHttpResponse(HttpResponse response) throws IOException {
 		StatusLine status = response.getStatusLine();
 		if (status != null) {
 			int statusCode = status.getStatusCode();
 			if (statusCode >= lowestOkCode && statusCode < lowestRedirectCode) {
 				return;
 			}
-			throw new IllegalStateException(String.format("Request response had error code %d.", statusCode));
+			throw new IOException(String.format("Request response had error code %d.", statusCode));
 		}
-		throw new IllegalStateException(String.format("Request response had no valid status."));
+		throw new IOException(String.format("Request response had no valid status."));
 	}
 	
-	protected final static String JsonUTF8 = "application/json;charset=UTF-8";
+	//protected final static String JsonUTF8 = "application/json;charset=UTF-8";
 	
 	protected HttpClient client;
 	
@@ -39,11 +38,11 @@ public abstract class HttpRequest {
 		client = new DefaultHttpClient();
 	}
 	
-	protected HttpResponse executeRequest(HttpRequestBase request, String content) throws IOException, ClientProtocolException {
+	protected HttpResponse executeRequest(HttpRequestBase request) throws IOException {
 		ExLog.i(TAG, "Requesting " + request.getMethod() +  " " + request.getURI().toString());
 		HttpResponse response = client.execute(request);
 		validateHttpResponse(response);
-		ExLog.i(TAG, "Response " + response.getStatusLine().toString() + " for " + content);
+		ExLog.i(TAG, "Response " + response.getStatusLine().toString());
 		return response;
 	}
 	
@@ -1,32 +0,0 @@
-package com.sap.sailing.racecommittee.app.data.http;
-
-import java.io.IOException;
-
-import org.apache.http.HttpResponse;
-import org.apache.http.client.ClientProtocolException;
-import org.apache.http.client.methods.HttpPost;
-import org.apache.http.entity.StringEntity;
-import org.apache.http.message.BasicHeader;
-import org.apache.http.protocol.HTTP;
-
-/**
- * @author Basil Hess
- * 
- * Used for POST Request to a REST Service
- * 
- * 'requestObjectAsString' is POSTed
- */
-public class PostHttpRequest extends HttpRequest {
-	
-	public HttpResponse post(String requestObjectAsString, String service) throws ClientProtocolException, IOException {
-		String jsonString = requestObjectAsString;
-		StringEntity entity = new StringEntity(jsonString);
-		entity.setContentType(JsonUTF8);
-		entity.setContentEncoding(new BasicHeader(HTTP.CONTENT_TYPE, JsonUTF8));
-
-		HttpPost post = new HttpPost(service);
-		post.setEntity(entity);
-		HttpResponse response = executeRequest(post, requestObjectAsString);
-		return response;
-	}
-}
@@ -1,29 +1,64 @@
 package com.sap.sailing.racecommittee.app.data.loaders;

-import com.sap.sailing.racecommittee.app.data.handlers.DataHandler;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.net.URI;

 import android.content.AsyncTaskLoader;
 import android.content.Context;

-public class DataLoader<T> extends AsyncTaskLoader<T> {
-	
-	private DataHandler<T> dataHandler;
+import com.sap.sailing.racecommittee.app.data.handlers.DataHandler;
+import com.sap.sailing.racecommittee.app.data.http.GetHttpRequest;
+import com.sap.sailing.racecommittee.app.data.parsers.DataParser;
+import com.sap.sailing.racecommittee.app.logging.ExLog;

-	public DataLoader(Context context, DataHandler<T> dataHandler) {
+public class DataLoader<T> extends AsyncTaskLoader<T> {
+	private static final String TAG = DataLoader.class.getName();
+	
+	protected URI requestUri;
+	protected DataParser<T> dataParser;
+	protected DataHandler<T> dataHandler;
+	protected volatile Exception lastException;
+
+	public DataLoader(Context context, URI requestUri,
+			DataParser<T> dataParser, DataHandler<T> dataHandler) {
 		super(context);
+		this.requestUri = requestUri;
+		this.dataParser = dataParser;
 		this.dataHandler = dataHandler;
 	}
 	
 	@Override
 	public T loadInBackground() {
-		// TODO Auto-generated method stub
+		lastException = null;
+		try {
+			return loadDataInBackground();
+		} catch (Exception e) {
+			lastException = e;
+			ExLog.e(TAG, String.format("Exception while loading data:\n%s", e.toString()));
+		}
 		return null;
 	}
+
+	private T loadDataInBackground() throws Exception {
+		GetHttpRequest getRequest = new GetHttpRequest();
+		InputStream inputStream = null;
+		Reader inputReader = null;
+		try {
+			inputStream = getRequest.get(requestUri);
+			inputReader = new InputStreamReader(inputStream);
+			return dataParser.parse(inputReader);
+		} finally {
+			inputStream.close();
+			inputReader.close();
+		}
+	}
 	
 	@Override
 	public void deliverResult(T data) {
 		if (data == null) {
-			dataHandler.onFailed(null);
+			dataHandler.onFailed(lastException);
 		} else {
 			dataHandler.onLoaded(data);
 		}
@@ -1,51 +0,0 @@
-package com.sap.sailing.racecommittee.app.data.loaders;
-
-import java.util.List;
-
-import android.content.AsyncTaskLoader;
-import android.content.Context;
-
-import com.sap.sailing.domain.common.Named;
-import com.sap.sailing.racecommittee.app.data.handlers.DataHandler;
-import com.sap.sailing.racecommittee.app.logging.ExLog;
-
-public class NamedListLoader<T extends Named> extends AsyncTaskLoader<List<T>> {
-
-	private static final String TAG = NamedListLoader.class.getName();
-	
-	private String requestUrl;
-	private DataHandler<T> dataHandler;
-
-	public NamedListLoader(Context context, String requestUrl, DataHandler<T> dataHandler) {
-		super(context);
-		this.requestUrl = requestUrl;
-		this.dataHandler = dataHandler;
-	}
-	
-	protected volatile Exception lastException;
-	
-	protected List<T> loadDataInBackground() throws Exception {
-		return new GetHttpRequest<List<T>>().get(requestUrl, typeref);
-	}
-	
-	@Override
-	public List<T> loadInBackground() {
-		lastException = null;
-		try {
-			return loadDataInBackground();
-		} catch (Exception e) {
-			lastException = e;
-			ExLog.e(TAG, e.toString());
-		}
-		return null;
-
-	}
-	
-	public void deliverResult (List<T> data){
-		if (data == null) {
-			dataHandler.onFailed(lastException);
-		} else {
-			dataHandler.onLoaded(data);
-		}
-	}
-}
@@ -0,0 +1,20 @@
+package com.sap.sailing.racecommittee.app.data.parsers;
+
+public class DataParseException extends Exception {
+	private static final long serialVersionUID = 3079074496188715438L;
+
+	public DataParseException() { }
+
+	public DataParseException(String detailMessage) {
+		super(detailMessage);
+	}
+
+	public DataParseException(Throwable throwable) {
+		super(throwable);
+	}
+
+	public DataParseException(String detailMessage, Throwable throwable) {
+		super(detailMessage, throwable);
+	}
+
+}
@@ -0,0 +1,9 @@
+package com.sap.sailing.racecommittee.app.data.parsers;
+
+import java.io.Reader;
+
+public interface DataParser<T> {
+
+	T parse(Reader reader) throws Exception;
+
+}
@@ -0,0 +1,36 @@
+package com.sap.sailing.racecommittee.app.data.parsers;
+
+import java.io.Reader;
+import java.util.ArrayList;
+import java.util.Collection;
+
+import org.json.simple.JSONArray;
+import org.json.simple.JSONObject;
+import org.json.simple.JSONValue;
+
+import com.sap.sailing.domain.base.Event;
+import com.sap.sailing.server.gateway.deserialization.JsonDeserializer;
+import com.sap.sailing.server.gateway.deserialization.impl.Helpers;
+
+public class EventsDataParser implements DataParser<Collection<Event>> {
+
+	private JsonDeserializer<Event> deserializer;
+	
+	public EventsDataParser(JsonDeserializer<Event> deserializer) {
+		this.deserializer = deserializer;
+	}
+
+	public Collection<Event> parse(Reader reader) throws Exception {
+		Object parsedResult = JSONValue.parse(reader);
+		JSONArray jsonArray = Helpers.toJSONArraySafe(parsedResult);
+		Collection<Event> events = new ArrayList<Event>();
+		
+		for (Object element : jsonArray) {
+			JSONObject json = Helpers.toJSONObjectSafe(element);
+			events.add(deserializer.deserialize(json));
+		}
+		
+		return events;
+	}
+
+}