CEP: source for real-time events or data feeds? - java

I am searching for free event sources that I can use within my java-application.
I am looking for something similar to YahooFinance, where one can query a bunch of stock info and retrieve the result as csv.
Ideally, an API or a URL with some query string would be perfect.

How about SuperFeedr?
You could also run some SPARQL-query on some SPARQL-Endpoint and "feed" the result back to your application. Here is a list of some endpoints (here including uptime and availability stats).
Twitter also offers an Streaming-API, where one can listen for status changes etc. Another way could be to implement some HTML-crawler that extracts interesting facts from webpages, but that's probably not what you are looking for...
Kind of related:
Flickr API - observe activities on flickr
SO - Cricket API

for this you can use Rss4j api which provide both read feed and also create you own feed.
hope this will help you

Related

Get notification in my client code

I want to get the notifications about any change in any issues in my jira server.
I have basic code for connecting jira from java code using jira-rest-java-client library that they have provided.
I searched their javadocs and also went through some classes in that API library but I could not find any methods/classes which would be helpful to me.
Does anyone know if it is possible to get notification events from changes in jira to my java code (may be via polling or something like that).
What do you want to achieve?
You want to have push notifications? There isn't any, IMHO.
UPDATE: However, there is this WebHook thingy: https://confluence.atlassian.com/display/JIRA/Managing+Webhooks.
I have no expertise with it, but it is promising, please read this short introduction also: http://blogs.atlassian.com/2012/10/jira-5-2-remote-integration-webhooks/.
You are looking for something that gives you back what changed in the last N minutes, something like the Activity Stream? You can get the RSS feed of Activity Streams for Projects and for Users.
How
The base URL is https://jira.contoso.com/activity. Then you can append querystring parameters, like maxResults for paginating.
Selecting the data source is through the filters you provide in the streams parameter. It looks like it is JQL, but it's not.
Examples:
List a project's activites: ?streams=key+IS+SOMEPROJ.
List a user's activites: ?streams=user+IS+foobar.
List event between two dates: ?streams=update-date+BETWEEN+1425300236000+1425300264999. (Note: the epoch is the millisecond precision epoch.)
List user activities in one project: ?streams=user+IS+JohnDoe&streams=key+IS+PROJECTKEY.
More complex ones: ?streams=user+IS+JohnDoe&streams=key+IS+PROJECTKEY&streams=activity+IS+issue:close
Watch out, it is case sensitive, on my JIRA 6.1.9, if I write Is instead of IS, I get an error page (but not if AFTER is not all uppercase o.O).
Also note, that spaces should be encoded as plus signs (+), not URL encoded (%20 for spaces).
If you go to your JIRA, and fetch the following URL: https://jira.yourserver.com/rest/activity-stream/1.0/config, it will list all the combinations it accepts.
What
The call returns a standard Atom feed. You can then process it with XML query tools, or with other Java-based RSS/ATOM reader libraries.
Noteworthy document about this topic: https://developer.atlassian.com/docs/atlassian-platform-common-components/activity-streams/consuming-an-activity-streams-feed

How to get multiple users timeline efficiently using twitter4j?

I want to get time line data for 2 users. Currently I am calling getUserTimeline("username",paging) method for both the users and combining the data. Is there any optimal way of doing it, for example, using one twitter api call or is this the only way it can be done? Please help.
As far as I know Twitter APIs does not allow to query for multiple users' timelines.
I guess you already did it, but you should double check that I am not wrong by looking at the official Twitter APIs documentation.

How to implement custom search on the server database in Android 2.3?

I have to implement custom search in my application for android 2.3.I have some EditText in which user type one letter and then I send response to the server, retrieve all the results matches this one letter and then I need to display them in a list. When user types second button I also need to send new response and refresh data and so on.
The question how can I do this in Android 2.3? What should i use?
This seems to be too open ended with too many questions to give a really helpful answer.
What you use in your app will heavily depend on how the server's API is expecting you to communicate. I, for one, am all for hiding the specifics of what a server does from the application and put all the "smarts" behind the API. So a query like:
http:/blah.com/getresults?search=a
would result in whatever matches 'a'. If it is searching a MySql Db, processing a Google search, or accessing files on the system doesn't matter.
Your code needs to worry about the interface to the API to make queries and processing the results, whether they're free formatted text, JSON objects, or whatever.
Maybe rewording your question or provide information on what you know would help.

Integration with Facebook Graph Api - update mechanism without Real-Time Updates

I'm working on a project which uses Facebook Graph Api to download information about users of our application and their Facebook friends. There is a need to update this data, but as I understand Real-Time Update is not an option. For example I would like to have update of profile feed of friends of our app user, and I don't see a way to do this with Real-Time Update.
Could someone give me some advice on this update mechanism? I need to update app users, their friend connections and profile feeds of users and their friends. I understand I'll have to poll Facebook servers to retrieve this data. What I'm trying to find out is some good practices when doing these things. Update frequency? Way to recognize that data has changed? If anyone has experience with this kind of things every advice would mean a lot.
Thanks.
You can use the since= query string parameter of the Graph API call. Here's some pseudocode to help you along
var usersLastPostDate = GetLastPostDateFromDataStore(userId);
if(usersLastPostDate not populated) {
streamItems = GraphApiGet(userId, "me/feed")
lastStreamItemDate = GetNewestStreamItemDate(streamItems)
StoreLastPostDateIntoDataStore(userId, lastStreamItemDate )
}
else {
streamItems = GraphApiGet(userId, "me/feed?since=" + usersLastPostDate )
}
Not massively useful for your use case (as you're wanting to get data which changes frequently), but worth pointing out that the Graph API now supports ETags - https://developers.facebook.com/blog/post/627/.
ETags will tell you if the data has changed since the last time you requested it. This won't stop you from hitting Facebooks API throttling limits, but is a quick and easy way to tell if the data has changed since you last asked for it.
There is no one answer to your question, as it depends on what your application is doing. How often do you need to get the updated information? If your data is stale for 5 minutes, is that really a problem? Can you grab the data from Facebook lazily, when some user action requires that you have it?
If you do need to do a lot of polling try and use non-blocking IO, especially if you're expecting to have a lot of open HTTP requests to Facebook whilst you're polling. Build a reliable queueing mechanism and HTTP poker to ensure requests are being made as expected. Without any idea of what technology stack you're using it's hard to be more specific than that.
HTH
What about this: Open Graph Subscription system ?

Java Bing Image Search

I have a small application in java which searches images using bing image search. The problem I am facing is that, its getting only first 20 images. May be because when we search on bing.com it populates first 20 images first and then its an infinite scrolling feature.
Is there any way to search more than 20 images using bing?
Cheers :)
I'm guessing this is because this site uses ajax to populate the "infinite" scrolling list as you call it.
You probably send an http request and get the initial page (btw on my browser I got 6 images accross x 4 down, i.e. 24 not 20; thinking about it maybe my client also got 20 only at first and got the last 4 w/ ajax...), and you'd need to do the paging trough by way of ajax requests.
At a glance, the xhtml and associated javascript of the page is very dense and somewhat obfuscated, It would take a while to get oriented... An alternative to analyzing this page is to instead use a packet sniffer (such as wireshark) and to capture the requests which take place when you scroll down.
Essentially this will likely expose some form of ajax request, which you can then easily emulate with java. Typically the ajax response is easy to parse whatever its nature (xml, jason, gzip...).
A possible snags to this well laid out plan is if the returned data in the ajax response is encrypted, for example where the extra images are bundled in some sort of envelope for which you'll then need to discover the format.
Depending on the actual task at hand, you may try alternatives such as automations within GreaseMonkey (on Firefox) or similar tools.
What of Bing API ?
Note that all the above approaches are akin to screen-scraping and hence quite sensitive to even minute changes in the Bing application, and, depending on effective usage and context, this could put the project in a legal grey area... A better approach may be to register and obtain a proper application ID with MS/Bing and to use the Bing API.
You are simulating a browser? Doesn't the Bing engine have an entry point for programs instead - a web service or so - which would make your task much easier.
EDIT: SDK appears to be here: http://msdn.microsoft.com/en-us/library/cc980922.aspx
Just wanted to post a direct answer to the question:
Bing uses Ajax (of course) for the infinite scroll. Each "tick" is based on a simple ajax get request, which accuires new images.
For instance, this url returns 30 results (121-151) in a "htmlraw" format based on the query "max payne".
http://www.bing.com/images/async?q=max+payne&format=htmlraw&first=121
Edit:
It works with the original url too, just add &first=NUMBER to the querystring. Example:
www.bing.com/images/search?q=payne&go=&form=QBLH&scope=images&filt=all&first=10
I am building my own bulk image collector (for a "learning project" for myself) and I found out that it is paginated like this.
FYI, Google and Bing are easy, Yahoo and Altavista (redundant, since their results are from Yahoo) are far more problematic - they don't post the directlink to the original image.
Have fun! :)
This can be done by using count parameter. For example, I tried GET "https://api.cognitive.microsoft.com/bing/v7.0/images/search?q=shoes&mkt=en-us&count=30" call and it returns 30 images.

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