com.google.api.client.googleapis.extensions.servlet.notifications.WebhookUtils Maven / Gradle / Ivy
/*
* Copyright 2013 Google Inc.
*
* 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 com.google.api.client.googleapis.extensions.servlet.notifications;
import com.google.api.client.googleapis.notifications.StoredChannel;
import com.google.api.client.googleapis.notifications.UnparsedNotification;
import com.google.api.client.googleapis.notifications.UnparsedNotificationCallback;
import com.google.api.client.util.Beta;
import com.google.api.client.util.LoggingInputStream;
import com.google.api.client.util.Preconditions;
import com.google.api.client.util.StringUtils;
import com.google.api.client.util.store.DataStore;
import com.google.api.client.util.store.DataStoreFactory;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* {@link Beta}
* Utilities for Webhook notifications.
*
* @author Yaniv Inbar
* @since 1.16
*/
@Beta
public final class WebhookUtils {
static final Logger LOGGER = Logger.getLogger(WebhookUtils.class.getName());
/** Webhook notification channel type to use in the watch request. */
public static final String TYPE = "web_hook";
/**
* Utility method to process the webhook notification from {@link HttpServlet#doPost} by finding
* the notification channel in the given data store factory.
*
* It is a wrapper around {@link #processWebhookNotification(HttpServletRequest,
* HttpServletResponse, DataStore)} that uses the data store from {@link
* StoredChannel#getDefaultDataStore(DataStoreFactory)}.
*
* @param req an {@link HttpServletRequest} object that contains the request the client has made
* of the servlet
* @param resp an {@link HttpServletResponse} object that contains the response the servlet sends
* to the client
* @param dataStoreFactory data store factory
* @exception IOException if an input or output error is detected when the servlet handles the
* request
* @exception ServletException if the request for the POST could not be handled
*/
public static void processWebhookNotification(
HttpServletRequest req, HttpServletResponse resp, DataStoreFactory dataStoreFactory)
throws ServletException, IOException {
processWebhookNotification(req, resp, StoredChannel.getDefaultDataStore(dataStoreFactory));
}
/**
* Utility method to process the webhook notification from {@link HttpServlet#doPost}.
*
*
The {@link HttpServletRequest#getInputStream()} is closed in a finally block inside this
* method. If it is not detected to be a webhook notification, an {@link
* HttpServletResponse#SC_BAD_REQUEST} error will be displayed. If the notification channel is
* found in the given notification channel data store, it will call {@link
* UnparsedNotificationCallback#onNotification} for the registered notification callback method.
*
* @param req an {@link HttpServletRequest} object that contains the request the client has made
* of the servlet
* @param resp an {@link HttpServletResponse} object that contains the response the servlet sends
* to the client
* @param channelDataStore notification channel data store
* @exception IOException if an input or output error is detected when the servlet handles the
* request
* @exception ServletException if the request for the POST could not be handled
*/
public static void processWebhookNotification(
HttpServletRequest req, HttpServletResponse resp, DataStore channelDataStore)
throws ServletException, IOException {
Preconditions.checkArgument("POST".equals(req.getMethod()));
InputStream contentStream = req.getInputStream();
try {
// log headers
if (LOGGER.isLoggable(Level.CONFIG)) {
StringBuilder builder = new StringBuilder();
Enumeration e = req.getHeaderNames();
if (e != null) {
while (e.hasMoreElements()) {
Object nameObj = e.nextElement();
if (nameObj instanceof String) {
String name = (String) nameObj;
Enumeration ev = req.getHeaders(name);
if (ev != null) {
while (ev.hasMoreElements()) {
builder
.append(name)
.append(": ")
.append(ev.nextElement())
.append(StringUtils.LINE_SEPARATOR);
}
}
}
}
}
LOGGER.config(builder.toString());
contentStream = new LoggingInputStream(contentStream, LOGGER, Level.CONFIG, 0x4000);
// TODO(yanivi): allow to override logging content limit
}
// parse the relevant headers, and create a notification
Long messageNumber;
try {
messageNumber = Long.valueOf(req.getHeader(WebhookHeaders.MESSAGE_NUMBER));
} catch (NumberFormatException e) {
messageNumber = null;
}
String resourceState = req.getHeader(WebhookHeaders.RESOURCE_STATE);
String resourceId = req.getHeader(WebhookHeaders.RESOURCE_ID);
String resourceUri = req.getHeader(WebhookHeaders.RESOURCE_URI);
String channelId = req.getHeader(WebhookHeaders.CHANNEL_ID);
String channelExpiration = req.getHeader(WebhookHeaders.CHANNEL_EXPIRATION);
String channelToken = req.getHeader(WebhookHeaders.CHANNEL_TOKEN);
String changed = req.getHeader(WebhookHeaders.CHANGED);
if (messageNumber == null
|| resourceState == null
|| resourceId == null
|| resourceUri == null
|| channelId == null) {
resp.sendError(
HttpServletResponse.SC_BAD_REQUEST,
"Notification did not contain all required information.");
return;
}
UnparsedNotification notification =
new UnparsedNotification(messageNumber, resourceState, resourceId, resourceUri, channelId)
.setChannelExpiration(channelExpiration)
.setChannelToken(channelToken)
.setChanged(changed)
.setContentType(req.getContentType())
.setContentStream(contentStream);
// check if we know about the channel, hand over the notification to the notification callback
StoredChannel storedChannel = channelDataStore.get(notification.getChannelId());
if (storedChannel != null) {
storedChannel.getNotificationCallback().onNotification(storedChannel, notification);
}
} finally {
contentStream.close();
}
}
private WebhookUtils() {}
}