001    /**
002     * Copyright (C) 2009-2011 the original author or authors.
003     * See the notice.md file distributed with this work for additional
004     * information regarding copyright ownership.
005     *
006     * Licensed under the Apache License, Version 2.0 (the "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package org.fusesource.restygwt.client;
020    
021    import com.google.gwt.core.client.GWT;
022    import com.google.gwt.http.client.Request;
023    import com.google.gwt.http.client.RequestCallback;
024    import com.google.gwt.http.client.Response;
025    
026    /**
027     *
028     * @author <a href="http://hiramchirino.com">Hiram Chirino</a>
029     */
030    public abstract class AbstractRequestCallback<T> implements RequestCallback {
031    
032        protected final Method method;
033    
034        protected MethodCallback<T> callback;
035    
036        public AbstractRequestCallback(Method method, MethodCallback<T> callback) {
037            this.method = method;
038            this.callback = callback;
039        }
040    
041        final public void onError(Request request, Throwable exception) {
042            this.method.request = request;
043            callback.onFailure(this.method, exception);
044        }
045    
046        final public void onResponseReceived(Request request, Response response) {
047            this.method.request = request;
048            this.method.response = response;
049            if (response == null) {
050                callback.onFailure(this.method, new FailedStatusCodeException("TIMEOUT", 999));
051            } else if (isFailedStatus(response)) {
052                callback.onFailure(this.method, new FailedStatusCodeException(response.getStatusText(),
053                        response.getStatusCode()));
054            } else {
055                T value;
056                try {
057                    GWT.log("Received http response for request: " + this.method.builder.getHTTPMethod()
058                            + " " + this.method.builder.getUrl(), null);
059                    String content = response.getText();
060                    if (content != null && content.length() > 0) {
061                        GWT.log(content, null);
062                        value = parseResult();
063                    } else {
064                        value = null;
065                    }
066                } catch (Throwable e) {
067                    GWT.log("Could not parse response: " + e, e);
068                    callback.onFailure(this.method, e);
069                    return;
070                }
071    
072                callback.onSuccess(this.method, value);
073            }
074        }
075    
076        protected boolean isFailedStatus(Response response) {
077            return !this.method.isExpected(response.getStatusCode());
078        }
079    
080        abstract protected T parseResult() throws Exception;
081    }