Dataflow Program on Google App Engine - google-app-engine

public class DemoServlet extends HttpServlet {
/*
code for getting the data from the REST api and putting it into
HashMap Collection and then creating the pipeline from that collection and writing the pipeline into bq table */
String[] credentials = {"--project=" + projectId, "--stagingLocation=" + staggingLocation};
PipelineOptionsFactory.Builder builder = PipelineOptionsFactory.fromArgs(credentials);
PipelineOptions options = builder.create();
//Setting to run the pipeline in google cloud.By Changing this parameter we can run even in local mode
options.setRunner(DataflowPipelineRunner.class);
//Creating pipeline with above options
Pipeline youTubeChannelPipeline = Pipeline.create(options);
PCollection<String> lines = null;
lines = youTubeChannelPipeline.apply(Create.of(allValues)).setCoder(StringUtf8Coder.of());
//Transforming PCollection<String> to PCollection<TableRow> and then writing to bq
bqRows = lines.apply(ParDo.named("Transforming String To TableRow").of(new DoFn() {
#Override
public void processElement(ProcessContext pc) throws Exception {
TableRow tmpRow = new TableRow();
String[] columns = pc.element().split(YoutubeConstants.COMA_DELIMITER);
for (int i = 0; i < no_of_col; i++) {
tmpRow.set(YoutubeConstants.CHANNEL_LEVEL_HEADERS[i], columns[i]);
}
pc.output(tmpRow);
}
}));
//Writing the rows in bq table
bqRows.apply(BigQueryIO.Write
.named("Write To BQ")
.to(destination_path)
.withSchema(schema)
.withWriteDisposition(BigQueryIO.Write.WriteDisposition.WRITE_APPEND)
.withCreateDisposition(BigQueryIO.Write.CreateDisposition.CREATE_IF_NEEDED));
youTubeChannelPipeline.run();
W 12:36:16.124 /demo
java.lang.RuntimeException: Failed to construct instance from factory method com.google.cloud.dataflow.sdk.runners.DataflowPipelineRunner#fromOptions
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.buildFromMethod(InstanceBuilder.java:228)
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.build(InstanceBuilder.java:161)
at com.google.cloud.dataflow.sdk.runners.PipelineRunner.fromOptions(PipelineRunner.java:52)
at com.google.cloud.dataflow.sdk.Pipeline.create(Pipeline.java:117)
at myapp.DemoServlet.doGet(DemoServlet.java:91)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.JdbcMySqlConnectionCleanupFilter.doFilter(JdbcMySqlConnectionCleanupFilter.java:60)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:257)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:146)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:482)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:234)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at com.google.appengine.runtime.Request.process-8f9b045d763b7321(Request.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:45)
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.buildFromMethod(InstanceBuilder.java:221)
at com.google.cloud.dataflow.sdk.util.InstanceBuilder.build(InstanceBuilder.java:161)
at com.google.cloud.dataflow.sdk.runners.PipelineRunner.fromOptions(PipelineRunner.java:52)
at com.google.cloud.dataflow.sdk.Pipeline.create(Pipeline.java:117)
at myapp.DemoServlet.doGet(DemoServlet.java:91)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:437)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:444)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:230)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:308)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:300)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:441)
... 1 more
Caused by: java.lang.RuntimeException: Unable to get application default credentials. Please see https://developers.google.com/accounts/docs/application-default-credentials for details on how to specify credentials. This version of the SDK is dependent on the gcloud core component version 2015.02.05 or newer to be able to get credentials from the currently authorized user via gcloud auth.
at com.google.cloud.dataflow.sdk.util.Credentials.getCredential(Credentials.java:122)
at com.google.cloud.dataflow.sdk.util.GcpCredentialFactory.getCredential(GcpCredentialFactory.java:43)
at com.google.cloud.dataflow.sdk.options.GcpOptions$GcpUserCredentialsFactory.create(GcpOptions.java:185)
at com.google.cloud.dataflow.sdk.options.GcpOptions$GcpUserCredentialsFactory.create(GcpOptions.java:175)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.getDefault(ProxyInvocationHandler.java:288)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:127)
at com.sun.proxy.$Proxy20.getGcpCredential(Unknown Source)
at com.google.cloud.dataflow.sdk.util.Transport.newDataflowClient(Transport.java:120)
at com.google.cloud.dataflow.sdk.options.DataflowPipelineDebugOptions$DataflowClientFactory.create(DataflowPipelineDebugOptions.java:157)
at com.google.cloud.dataflow.sdk.options.DataflowPipelineDebugOptions$DataflowClientFactory.create(DataflowPipelineDebugOptions.java:154)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.getDefault(ProxyInvocationHandler.java:288)
at com.google.cloud.dataflow.sdk.options.ProxyInvocationHandler.invoke(ProxyInvocationHandler.java:127)
at com.sun.proxy.$Proxy20.getDataflowClient(Unknown Source)
at com.google.cloud.dataflow.sdk.runners.DataflowPipelineRunner.<init>(DataflowPipelineRunner.java:160)
<continued in next message>
W 12:36:16.124 <continued from previous message>
at com.google.cloud.dataflow.sdk.runners.DataflowPipelineRunner.fromOptions(DataflowPipelineRunner.java:155)
... 34 more
Caused by: java.io.IOException: Application Default Credentials failed to create the Google App Engine service account credentials class com.google.api.client.googleapis.extensions.appengine.auth.oauth2.AppIdentityCredential$AppEngineCredentialWrapper. Check that the component 'google-api-client-appengine' is deployed.
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.tryGetAppEngineCredential(DefaultCredentialProvider.java:274)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.getDefaultCredentialUnsynchronized(DefaultCredentialProvider.java:159)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.getDefaultCredential(DefaultCredentialProvider.java:86)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.getApplicationDefault(GoogleCredential.java:213)
at com.google.api.client.googleapis.auth.oauth2.GoogleCredential.getApplicationDefault(GoogleCredential.java:191)
at com.google.cloud.dataflow.sdk.util.Credentials.getCredential(Credentials.java:120)
... 48 more
Caused by: java.lang.ClassNotFoundException: com.google.api.client.googleapis.extensions.appengine.auth.oauth2.AppIdentityCredential$AppEngineCredentialWrapper
at com.google.appengine.runtime.Request.process-8f9b045d763b7321(Request.java)
at java.lang.Class.forName(Class.java:136)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.forName(DefaultCredentialProvider.java:208)
at com.google.api.client.googleapis.auth.oauth2.DefaultCredentialProvider.tryGetAppEngineCredential(DefaultCredentialProvider.java:259)
... 53 more

Support for getting credentials compatible with Dataflow via Application Default Credentials in AppEngine exists in version 1.9.20+ of the Google API libraries. Please make sure that your WAR that you deploy to AppEngine contains google-api-client version 1.9.20+ and google-api-client-appengine version 1.9.20+. Beware that you may need to upgrade other dependencies because of this change.

Related

Class def not found from Kotlin code

I have Kotlin code:
cluster.removeIf { t: SolutionElement -> t.timeStart < minimumDate } //Clusters.kt:66
Where cluster object is kotlin Mutable list. When I try to run this code on Google App Engine standard environment I got an error:
java.lang.NoClassDefFoundError: java/util/function/Predicate
at com.google.appengine.runtime.Request.process-4a2a3dcd2b375db7(Request.java)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:820)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at java.lang.ClassLoader.loadClass(ClassLoader.java:375)
at net.toolla.teamly.services.matcher.Clusters.removeExpired(Clusters.kt:66)
at net.toolla.teamly.services.matcher.Clusters.pickMore(Clusters.kt:31)
at net.toolla.teamly.services.matcher.BestMatchWorker.getSolutionElements(BestMatchWorker.java:232)
at net.toolla.teamly.services.matcher.BestMatchWorker.match(BestMatchWorker.java:116)
at net.toolla.teamly.services.matcher.MatcherService.doPost(MatcherService.java:37)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:454)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:461)
at com.google.tracing.CurrentContext.runInContext(CurrentContext.java:297)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:320)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:312)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:458)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: java.util.function.Predicate
at com.google.appengine.runtime.Request.process-4a2a3dcd2b375db7(Request.java)
In build.gradle for this module, I had:
compileKotlin{
kotlinOptions{
jvmTarget = 1.6
}
}
Without that parameter error was:
Uncaught exception from servlet
java.lang.NoClassDefFoundError: net/toolla/teamly/services/matcher/Clusters$removeExpired$1
Where "removeExpired" is name of the function which contains the above line.
I changed the code above to some less convenient and older syntax, but it would be great to know how to use some more up to date techniques.
The class java.util.function.Predicate was introduced in Java 8. So run it with 8. About th
...
* #since 1.8
*/
#FunctionalInterface
public interface Predicate<T> {
About that error:
java.lang.NoClassDefFoundError:
net/toolla/teamly/services/matcher/Clusters$removeExpired$1
Ensure that you have that class on your classpath
Instead of removeIf, which is a method from JDK 8 and is therefore not supported on JDK 6, you can use the removeAll method from the Kotlin standard library, which is supported on all JDK versions.

SocketTimeoutException using Parse REST API at GAE

I use GAE as a server for my app, and when something occurs I want to notify the relevant users about it. I use Parse REST API to do this push notification (not GCM because I have iphone user too). But sometimes (can't realize when) I get
java.net.SocketTimeoutException: Timeout while fetching: https://api.parse.com/1/push
at com.google.appengine.api.urlfetch.URLFetchServiceImpl.fetch(URLFetchServiceImpl.java:52)
at com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection.fetchResponse(URLFetchServiceStreamHandler.java:417)
at com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection.getInputStream(URLFetchServiceStreamHandler.java:296)
at com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection.getResponseCode(URLFetchServiceStreamHandler.java:149)
at com.starling.parse.PushNotifications.sendRequest(PushNotifications.java:113)
at com.starling.parse.PushNotifications.sendPushUpdate(PushNotifications.java:71)
at com.starling.parse.PushNotifications.notifyUsersWithSongUpdates(PushNotifications.java:121)
at com.straling.server.db.actions.VoteActions$1.run(VoteActions.java:86)
at com.straling.server.db.actions.VoteActions$1.run(VoteActions.java:1)
at com.googlecode.objectify.impl.cmd.ObjectifyImpl.transactOnce(ObjectifyImpl.java:257)
at com.googlecode.objectify.impl.cmd.ObjectifyImpl.transactNew(ObjectifyImpl.java:234)
at com.googlecode.objectify.impl.cmd.ObjectifyImpl.transactNew(ObjectifyImpl.java:224)
at com.googlecode.objectify.impl.cmd.ObjectifyImpl.transact(ObjectifyImpl.java:216)
at com.straling.server.db.actions.VoteActions.newVote(VoteActions.java:50)
at com.straling.server.servlets.VoteSongServlet.doPost(VoteSongServlet.java:75)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.googlecode.objectify.cache.AsyncCacheFilter.doFilter(AsyncCacheFilter.java:59)
at com.googlecode.objectify.ObjectifyFilter.doFilter(ObjectifyFilter.java:49)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.socket.dev.DevSocketFilter.doFilter(DevSocketFilter.java:74)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.ResponseRewriterFilter.doFilter(ResponseRewriterFilter.java:110)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:34)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:61)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:125)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:94)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:380)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:938)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:755)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:218)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)
and when it happens, it happens immediately (not after 45 sec. which is GAE request timeout)?
My code :
private static void sendRequest(String payload) throws IOException {
HttpURLConnection connection = null;
URL urlObject = new URL("https://api.parse.com/1/push");
connection = (HttpURLConnection) urlObject.openConnection();
connection.setRequestProperty("X-Parse-Application-Id", APPLICATION_ID);
connection.setRequestProperty("X-Parse-REST-API-Key", REST_API_KEY);
connection.setRequestProperty("Content-Type", "application/json");
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.getOutputStream().write(payload.getBytes());
connection.getResponseCode();
}
The payload string :
{ "channel": "vID18483", "data": {"action": "com.starling.app.UPDATE_SONGS","songs":[{"id":36209,"length":0,"points":104,"isPlaying":false,"isInPlaylist":true}]}}
Any suggestions?
Thanks,
Dan
URLConnection on GAE has a default deadline of 5 seconds. You should increase that by setting connection timeout via setConnectTimeout() plus the read timeout via setReadTimeout(). Both connection and read timeout together are a deadline time, which can be max 60s.

New to GWT, Google Code and App Engine

I am new in the whole Google code thing.
So my question is the following.
Having downloaded the Google Plugin for eclipse, i have created a new Project, which has automatically created an example code, the Greeting Example.
So I deployed it to the app Engine, an all worked OK. So now i am trying to add some functionality.. Via eclipse, I downloaded the Google Contacts API and transferred the Jars in the classpath as well as in the LIB directory.
So, in the server side of the project, in file GreetingServiceImpl.java I have added the following line
ContactsService contactsService = new ContactsService("Contacts");
so the file looks like this..
package com.gnt.server;
import com.gnt.client.GreetingService;
import com.gnt.shared.FieldVerifier;
import com.google.gdata.client.contacts.ContactsService;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
/**
* The server side implementation of the RPC service.
*/
#SuppressWarnings("serial")
public class GreetingServiceImpl extends RemoteServiceServlet implements
GreetingService {
public String greetServer(String input) throws IllegalArgumentException {
// Verify that the input is valid.
if (!FieldVerifier.isValidName(input)) {
// If the input is not valid, throw an IllegalArgumentException back to
// the client.
throw new IllegalArgumentException(
"Name must be at least 4 characters long");
}
String serverInfo = getServletContext().getServerInfo();
String userAgent = getThreadLocalRequest().getHeader("User-Agent");
// Escape data from the client to avoid cross-site script vulnerabilities.
input = escapeHtml(input);
userAgent = escapeHtml(userAgent);
ContactsService contactsService = new ContactsService("Contacts");
return "Hello, " + input + "!<br><br>I am running " + serverInfo
+ ".<br><br>It looks like you are using:<br>" + userAgent;
}
/**
* Escape an html string. Escaping data received from the client helps to
* prevent cross-site script vulnerabilities.
*
* #param html the html string to escape
* #return the escaped string
*/
private String escapeHtml(String html) {
if (html == null) {
return null;
}
return html.replaceAll("&", "&").replaceAll("<", "<")
.replaceAll(">", ">");
}
}
Now when i deploy this to the App Engine, i get the following error..
javax.servlet.ServletContext log: Exception while dispatching incoming RPC call
com.google.gwt.user.server.rpc.UnexpectedException: Service method 'public abstract java.lang.String com.gnt.client.GreetingService.greetServer(java.lang.String) throws java.lang.IllegalArgumentException' threw an unexpected exception: java.lang.NoClassDefFoundError: com/google/gdata/client/GoogleService
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:385)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:588)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:102)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:249)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:477)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.NoClassDefFoundError: com/google/gdata/client/GoogleService
at com.google.appengine.runtime.Request.process-ff033622b2cd8d3f(Request.java)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
at com.gnt.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:32)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:43)
at com.google.gwt.user.server.rpc.RPC.invokeAndEncodeResponse(RPC.java:569)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processCall(RemoteServiceServlet.java:208)
at com.google.gwt.user.server.rpc.RemoteServiceServlet.processPost(RemoteServiceServlet.java:248)
at com.google.gwt.user.server.rpc.AbstractRemoteServiceServlet.doPost(AbstractRemoteServiceServlet.java:62)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
... 1 more
Caused by: java.lang.ClassNotFoundException: com.google.gdata.client.GoogleService
at com.google.appengine.runtime.Request.process-ff033622b2cd8d3f(Request.java)
... 34 more
How can this be; The necessary libraries are in the classpath and Lib directory...
I ve been searching for two days now and i have not found any answer...
For Testing purposes, i have added the Apache commons Lib and called a method from that lib and it worked perfectly inside the App Engine.
So what am i doing wrong? How can i use the Contacts API inside App Engine?
Thank you very much for your time!
You are probably missing the Google Data JARs.
See here for a tutorial. Make sure that gdata-client, gdata-client-meta, gdata-core, and gdata-media JARs are in your build path.

TransientFailureException -- > While leasing tasks from pull queue

We are using pull queues with backends in our scenario and our backend tries to lease tasks from our pull queue after some fixed intervals and in case there are no tasks , it does not do anything and in case there are any , those are processed . Yesterday we got this TransientFailureException in our system , which exactly is happening while my servlet is trying to lease task from pull queue . And the exception kept coming until we stopped our backend .
Our code snippet --
{
Boolean leasedTaskFromFastQueue = true;
Queue fastQueue = QueueFactory.getQueue("FastQueue");
Queue slowQueue = QueueFactory.getQueue("SlowQueue");
List<TaskHandle> tasks = fastQueue.leaseTasks(
3600, TimeUnit.SECONDS, 1);
TaskHandle taskHandle = null;
if(tasks.size() > 0) {
taskHandle = tasks.get(0);
}
}
We aret getting error on the line where we lease task from fastQueue , which is a pull queue
<queue>
<name>FastQueue</name>
<mode>pull</mode>
</queue>
I am also pasting my error trace , in case that helps
com.google.appengine.api.taskqueue.TransientFailureException:
at com.google.appengine.api.taskqueue.QueueApiHelper.translateError(QueueApiHelper.java:79)
at com.google.appengine.api.taskqueue.QueueApiHelper.translateError(QueueApiHelper.java:139)
at com.google.appengine.api.taskqueue.QueueApiHelper.makeSyncCall(QueueApiHelper.java:53)
at com.google.appengine.api.taskqueue.QueueImpl.leaseTasksInternal(QueueImpl.java:709)
at com.google.appengine.api.taskqueue.QueueImpl.leaseTasks(QueueImpl.java:731)
at com.implementhit.advancedsupport.server.queue.Backend.doGet(Backend.java:50)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.bitdual.appengine.tools.datastore.server.NamespaceFilter.doFilter(NamespaceFilter.java:96)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:102)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:249)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:477)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:679)
It happend to us also, TransientFailureException is an internal error that as far as we could see had nothing to do with our code. We ended up by automatically restarting the backend if 50 errors happened in a row.

How can I retrieve a blobstore file by name

I wrote the following code:
FileService fileService = FileServiceFactory
.getFileService();
// Create a new Blob file with mime-type "text/plain"
AppEngineFile file = fileService.createNewBlobFile(
"image/jpeg", name);
if(null!=file)
log.warn(file.toString());
FileReadChannel readChannel =
fileService.openReadChannel(
file, true);
// Again, different standard Java ways of reading from
// the
// channel.
BufferedReader reader = new BufferedReader(Channels
.newReader(readChannel, "UTF8"));
String line = reader.readLine();
resp.setContentType("text/plain");
resp.getWriter().println(line);
readChannel.close();
But unfortunately, it gives me the following exception:
Uncaught exception from servlet
com.google.appengine.api.files.FinalizationException
at com.google.appengine.api.files.FileServiceImpl.translateException(FileServiceImpl.java:597)
at com.google.appengine.api.files.FileServiceImpl.makeSyncCall(FileServiceImpl.java:574)
at com.google.appengine.api.files.FileServiceImpl.open(FileServiceImpl.java:496)
at com.google.appengine.api.files.FileServiceImpl.openForRead(FileServiceImpl.java:456)
at com.google.appengine.api.files.FileServiceImpl.openForRead(FileServiceImpl.java:447)
at com.google.appengine.api.files.FileServiceImpl.openReadChannel(FileServiceImpl.java:202)
at com.myfileshost.MyfileshostServlet.doGet(MyfileshostServlet.java:362)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
at com.google.apphosting.utils.servlet.ParseBlobUploadFilter.doFilter(ParseBlobUploadFilter.java:102)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.runtime.jetty.SaveSessionFilter.doFilter(SaveSessionFilter.java:35)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
at com.google.apphosting.runtime.jetty.AppVersionHandlerMap.handle(AppVersionHandlerMap.java:249)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
at com.google.apphosting.runtime.jetty.RpcRequestParser.parseAvailable(RpcRequestParser.java:76)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at com.google.apphosting.runtime.jetty.JettyServletEngineAdapter.serviceRequest(JettyServletEngineAdapter.java:135)
at com.google.apphosting.runtime.JavaRuntime$RequestRunnable.run(JavaRuntime.java:446)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at com.google.apphosting.runtime.ThreadGroupPool$PoolEntry.run(ThreadGroupPool.java:251)
at java.lang.Thread.run(Thread.java:679)
When a file is created via a GAE FileService it must be finalized before it can be read.
Javadoc of openReadChannel(..) clearly states that this method throws FinalizationException if file is not finalized.
Here is a full example on how to create file, finalize it and then read from it: https://developers.google.com/appengine/docs/java/blobstore/overview#Writing_Files_to_the_Blobstore

Resources