playn.http.HttpHtml.java Source code

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Here is the source code for playn.http.HttpHtml.java

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/**
 * Copyright 2010 The PlayN Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package playn.http;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import playn.core.PlayN;
import playn.core.util.Callback;

import com.google.gwt.xhr.client.ReadyStateChangeHandler;
import com.google.gwt.xhr.client.XMLHttpRequest;

/**
 * XML Http Request implementation of {@link Http}.
 *
 * @author Inderjeet Singh
 */
public class HttpHtml extends Http {

    @Override
    protected void doSend(HttpRequest request, Callback<HttpResponse> callback) {
        HttpMethod method = request.getMethod();
        switch (method) {
        case GET:
        case POST:
        case PUT:
            invokeHttpMethod(request, callback);
            break;
        default:
            throw new UnsupportedOperationException(method.toString());
        }
    }

    public void invokeHttpMethod(final HttpRequest request, final Callback<HttpResponse> callback) {
        try {
            XMLHttpRequest xhr = XMLHttpRequest.create();
            xhr.open(request.getMethod().toString(), request.getUrl());
            for (Map.Entry<String, String> header : request.getHeaders()) {
                xhr.setRequestHeader(header.getKey(), header.getValue());
            }
            xhr.setOnReadyStateChange(new ReadyStateChangeHandler() {
                @Override
                public void onReadyStateChange(XMLHttpRequest xhr) {
                    if (xhr.getReadyState() == XMLHttpRequest.DONE) {
                        try {
                            gotResponse(request, xhr, xhr.getResponseText(), callback);
                        } catch (IOException e) {
                            callback.onFailure(e);
                        }
                    }
                }
            });
            xhr.send(request.getBody());
        } catch (Exception e) {
            callback.onFailure(e);
        }
    }

    private void gotResponse(final HttpRequest req, XMLHttpRequest xhr, String responseBody,
            final Callback<HttpResponse> callback) throws IOException {
        int statusCode = -1;
        String statusLineMessage = null;
        Map<String, String> responseHeaders = new HashMap<String, String>();
        try {
            statusCode = xhr.getStatus();
            statusLineMessage = xhr.getStatusText();
            for (String headerName : getAllResponseHeaderNames(xhr)) {
                String value = xhr.getResponseHeader(headerName);
                responseHeaders.put(headerName, value);
            }
            HttpResponse response = new HttpResponse(statusCode, statusLineMessage, responseHeaders, responseBody);
            callback.onSuccess(response);
        } catch (Throwable t) {
            throw new HttpException(statusCode, statusLineMessage, responseBody, t, HttpErrorType.SERVER_ERROR);
        }
    }

    private List<String> getAllResponseHeaderNames(XMLHttpRequest xhr) {
        List<String> headers = new ArrayList<String>();
        String all = xhr.getAllResponseHeaders();
        for (String line : all.split("\n")) { // Can't use BufferedReader because of GWT
            try {
                String[] tokens = line.split(":");
                // ignore the actual header value, just add the header name
                if (tokens.length > 0)
                    headers.add(tokens[0]);
            } catch (Exception e) {
                PlayN.log().warn("Error while processing a response header", e);
                // ignore this and continue reading other response headers
            }
        }
        return headers;
    }
}