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Ralf Coby

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Recent posts by Ralf Coby

In case, somebody discovers this thread via Google:

Go to the websites below to solve problems by implementing the sort and search algorithms like mergesort etc.
10 months ago
Hi and thank you for the replies.

As I supposed, there are no algorithm games

So, I try to create my own algorithm games with the exercises of the math-pages.

thank you
11 months ago
is there a website/ board with algorithm games?

I am looking for exercises to improve my algorithm skills regarding quicksort, merge sort, hashing etc.

Thank you in advance
11 months ago
Hi and thanks for your answer!
Today, my certification got listed under the menu "PVUE Results History" on the certview-page.

But if I click "view", then I just get my score, photo and feedback which are listed on the certifiaction.

Is it new a certification-design?
Why there is no longer the old design in use?

The old design was very aesthetic !

today, I took my exam and certview says, that I passed the Java OCA Exam.
But i cant see my certification.pdf file. I only see my score, my picture and feedback.

Could you tell me, how I can get my certification?

Greets and thanks in advance
I'll order it via a pearson VUE testcenter.
if i choose the java oca voucher, and i select "bank transfer", then nothing happens.
Am I the only one, for who its not working for?
Maybe it's because of the text-field next to the select-button? I don't know what i have to type in. The Textfield only says "Wire Transfer or bank deposit".

I hope you can help me.

This works fiiiinnee!
There is no setKeepAlive(), but actually, this code does what I wanna do!

For anyone, who ist interessted about:


3 years ago
I have set setKeepAlive() before the connect-method connects to the server.

Surprisingly, on the one hand, a ACK-Flag hasn't been set by invoking the method.

Now, I get the exception below:

So, the client gets the message from the server, which the Client has send.
Then, I think, the client trys to reconnect to the server, but it isn't possible, because the client has closed its InputStreams and OutputStreams.

On the other hand, this exception tells me, that the client trys to get a "keepAlive"-Connection to the server.

So, i have to figure out how to close the Streams in the right moments.

by now, my code looks like this:



3 years ago

Stephan van Hulst wrote:I believe the problem is that you're trying to set KeepAlive after the connection has been established. Try a constructor that doesn't immediately connect to the endpoint (such as the parameterless constructor), call setKeepAlive(), and finally call connect().

Thanks for your help. I will try it tomorrow and then I will reply.

3 years ago

I have written a little, simple Protocol to test the "setKeepAlive()"-method.

So, a little, simple echo-Server and a client.

I want that the Server keeps the connection to the client stable, wether or not the server has send a message to the client.

So, I try to work with the "KeepAlive()-Method" from the

But I am not able to find any examples with keepAlive() or any documentations.

Here is my example-protocol:



I hope you can help me.

Thanks in advance
3 years ago
And thank you for the recommended book!!!
3 years ago
WOW!!! That's EXTREME!!!

Thank you!
3 years ago
Hi and thanks for answering.

I know how to handle http-requests with the apache-http-client.

But I dont know how to implement the htt-protocol to javaFX WebView or JavaFx WebEngine.

For example:

So, if i deploy my code with this html-text, and if I click the button, then nothing happens.

So, i need to know a way how to teach WebView or WebEngine to handle with requests.

For example something like this:

if(signal == 1){
transferValueTo apacheHttpPostClient

I just wanna write a little WebBrowser with WebView, WebEngine and apache-http-client
3 years ago
Hi community!

I am working with JavaFx WebView and http-apache-client.

I am asking myself how to set a value from HTML-WebView-Page to an average POJO.

So, if you click the button (PostRequest) it should set an value to a POJO and after this i can handle it with the http-apache-client.

But I dont know how to "translate" a value from a textfield after clicking the button.

Thank you in advance!
3 years ago