/*
* Copyright 2014 Jeanfrancois Arcand
*
* 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 org.atmosphere.interceptor;
import org.atmosphere.cpr.Action;
import org.atmosphere.cpr.AsyncIOInterceptorAdapter;
import org.atmosphere.cpr.AsyncIOWriter;
import org.atmosphere.cpr.AtmosphereConfig;
import org.atmosphere.cpr.AtmosphereInterceptorAdapter;
import org.atmosphere.cpr.AtmosphereInterceptorWriter;
import org.atmosphere.cpr.AtmosphereRequest;
import org.atmosphere.cpr.AtmosphereResource;
import org.atmosphere.cpr.AtmosphereResponse;
import org.atmosphere.cpr.HeaderConfig;
import org.atmosphere.util.StringEscapeUtils;
import org.atmosphere.util.Utils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
/**
* JSONP Transport Support.
*
* @author Jeanfrancois Arcand
*/
public class JSONPAtmosphereInterceptor extends AtmosphereInterceptorAdapter {
private static final Logger logger = LoggerFactory.getLogger(JSONPAtmosphereInterceptor.class);
private String endChunk = "\"});";
private String startChunk = "({\"message\" : \"";
private AtmosphereConfig config;
@Override
public void configure(AtmosphereConfig config) {
this.config = config;
}
@Override
public Action inspect(AtmosphereResource r) {
if (Utils.webSocketMessage(r)) return Action.CONTINUE;
final AtmosphereRequest request = r.getRequest();
final AtmosphereResponse response = r.getResponse();
// Shield from Broken server
String uri = request.getRequestURI() == null ? "" : request.getRequestURI();
if (r.transport().equals(AtmosphereResource.TRANSPORT.JSONP) || uri.indexOf("jsonp") != -1) {
super.inspect(r);
if (uri.indexOf("jsonp") != -1) {
startChunk = "(\"";
endChunk = "\");\r\n\r\n";
}
AsyncIOWriter writer = response.getAsyncIOWriter();
if (AtmosphereInterceptorWriter.class.isAssignableFrom(writer.getClass())) {
AtmosphereInterceptorWriter.class.cast(writer).interceptor(new AsyncIOInterceptorAdapter() {
String callbackName() {
String callback = request.getParameter(HeaderConfig.JSONP_CALLBACK_NAME);
if (callback == null) {
// Look for extension
String jsonp = (String) config.properties().get(HeaderConfig.JSONP_CALLBACK_NAME);
if (jsonp != null) {
callback = request.getParameter(jsonp);
}
}
return callback;
}
@Override
public void prePayload(AtmosphereResponse response, byte[] data, int offset, int length) {
String callbackName = callbackName();
response.write(callbackName + startChunk);
}
@Override
public byte[] transformPayload(AtmosphereResponse response, byte[] responseDraft, byte[] data) throws IOException {
String charEncoding = response.getCharacterEncoding() == null ? "UTF-8" : response.getCharacterEncoding();
return escapeForJavaScript(new String(responseDraft, charEncoding)).getBytes(charEncoding);
}
@Override
public void postPayload(AtmosphereResponse response, byte[] data, int offset, int length) {
response.write(endChunk, true);
}
});
} else {
logger.warn("Unable to apply {}. Your AsyncIOWriter must implement {}", getClass().getName(), AtmosphereInterceptorWriter.class.getName());
}
}
return Action.CONTINUE;
}
protected String escapeForJavaScript(String str) {
try {
str = StringEscapeUtils.escapeJavaScript(str);
} catch (Exception e) {
logger.error("Failed to escape", e);
str = null;
}
return str;
}
@Override
public String toString() {
return "JSONP Interceptor Support";
}
}