All Questions
Tagged with data-stream java
37 questions
0
votes
1
answer
33
views
Flink GlobalWindow Trigger only process the trigger event
I have datastream keyby by an event property, that is then passed to a globalwindow, trigged when a specific event comes in, the issue is that when the window is trigged to process the events, it only ...
- 3
0
votes
0
answers
367
views
Problems with sink on flink
[enter image description here][1] I could do this to try first, this works well this just print the data on another topic I trie to follow the same logic but don get the result
package org.example;
...
- 3
0
votes
1
answer
182
views
FLINK left join three DataStreams using cogroup
I'm trying to merge three stream into a single stream. Tried union but was unable to proceed as the schema's are different and if I merge the schema it becomes too large.
So, I'm using **cogroup ** ...
- 28
1
vote
2
answers
1k
views
How to select kafka topic dynamically in apache flink kafka sink?
I'm using KafkaSink as the sink in my flink application and I require to send stringifiedJSONs to different Kafka topics based on some key-value pairs (for example, a few JSONs go to topic1 and a few ...
0
votes
0
answers
147
views
How do I merge audio streams into one file using javax.sound.sampled?
I've been learning Java to build what equates to an audio file merger/mixer.
The idea is to insert voice files into a 4 minute music bed.
I am able to create individual streams and output to different ...
- 23
0
votes
1
answer
545
views
Flink DataStream element not updating
I have a code like:
DataStream<Sample> stream = ...
stream.map(x => {
x.setVal(10);
return x;
});
// Sample class looks like this:
class Sample {
int val = 5;
public void ...
0
votes
1
answer
419
views
Flink Datastreams Evictor
I'm using Flink DataStreams to join 2 streams (a Book stream and a Publisher stream). I'm trying to remove elements by using evictor in case they are deleted from the database, which is indicated with ...
- 3
0
votes
1
answer
693
views
Apache Flink join different DataStreams on specific key
I have two DataStreams, the first one called DataStream<String> source which receive records from a message broker, and the second one is a SingleOutputOperator<Event> events, which is the ...
- 1,192
1
vote
2
answers
2k
views
Apache Flink: How to update Source Function in Unit Test?
I need my Flink job to read from a local instance of a Source Function and update every time the Source Function instance's data changes within the unit testing code itself rather than a stream.
...
0
votes
1
answer
6k
views
Having trouble getting readAllBytes() method to work
Other students in my class have gotten this code to work, but I get an error. I am trying to use the readAllBytes() method for an assignment and I can't get it to work. My teacher there is another ...
0
votes
1
answer
288
views
Flink and Cassandra Connection Issue
Has anyone faced any issue with Connecting to Cassandra from a Flink Job when the Connection is made outside the Flink's DataStreams normally?
Session session = clusterBuilder.getCluster()....
- 29
-1
votes
1
answer
55
views
Java Socket does not error but is not functional(?)
I have a very basic understanding of clients, servers, sockets, input and output streams, etc. related to having servers. However, my socket that I created does not seem to work. I used many unused ip ...
- 157
0
votes
1
answer
2k
views
Read CSV file with 3 columns into Datastream. JAVA Apache Flink
I've been struggling for a while setting up a flink application that creates a Datastream<Tuple3<Integer, java.sql.Time, Double>> from a csv file. The columns in this file (columns ID, ...
- 216
0
votes
1
answer
1k
views
Flink map stream csv file into Tuple
I am trying to map a CSV file, already consumed by Flink and produced by Kafka, into a Tuple4. My CSV file has 4 columns and I want to map each row into a Tuple4. The problem is that I do not know how ...
- 457
8
votes
1
answer
452
views
Transform data stream using processor implemented via Flow APIs
I was going through the Community#DOC-1006738 from Oracle related to the concurrency concepts of Flow.Publisher and Flow.Subscriber. There on one can find the Sample code to transform data stream ...
- 31.6k
-1
votes
1
answer
201
views
java socket(change the boolean in another class) and datastream
now i'm making chatting program.
but there are some problems.
first, in login process, when i send the id/pw to server, server sends that is right or wrong (protocol 3000 or 3001). then, client will ...
- 33
0
votes
1
answer
146
views
Send stream of Data from client program (running in VM) to server program(on Host OS) using socket programming in Java
A Client socket Program (in windows VM) generates integer from 1 to 10 as per below code
public class ClientSocket {
public static void main(String[] args)
{
try{
InetAddress ...
- 2,796
1
vote
1
answer
463
views
Node.JS and Java PUB/SUB
I'm trying to build an application that the communication will be done by a node.js server. This node server will receive messages from others peers.
My node.js code is:
var zmq = require('zmq'),
...
- 8,480
0
votes
0
answers
489
views
Problems running Flink tutorial RideCleansing
Hi my Flink friends,
I have several problems regarding the execution of my first Apache Flink Job. I did all the steps of this "1-handsOn-Tutorial":
https://dataartisans.github.io/flink-training/...
- 31
0
votes
1
answer
564
views
BLE Connection dropping
I am trying to stream data using BLE but the device does not stay connected. Currently, we can connect and print out all the UUIDs of services and characteristics and establish connection. It connects ...
0
votes
0
answers
55
views
Server Side Android Application failing to start
this is my first question and ive been stuck on this unknown problem for day now. The app was running successfully till i added some new code to make a custom listview component and to read some ...
0
votes
1
answer
1k
views
Reading data from a socket java
So, I'm trying to read data from a socket. I have established a connection and sent a message to the other socket which is listening for such, but it doesn't seem to recieve anything.
Client code:
...
0
votes
1
answer
463
views
Not able to write to file - java
Pretty sure this should be really easy, but I can't write to a file. No I/O exception is thrown nothing. I was having a similar problem reading earlier and I tried a hundred different ways until
...
- 162
0
votes
2
answers
70
views
Combining text- and bit-information in a file in Java?
Alright, so we need to store a list of words and their respective position in a much bigger text. We've been asked if it's more efficient to save the position represented as text or represented as ...
- 1,652
1
vote
0
answers
301
views
get data stream java - working with java stream api
i got an assignment working with data stream and java.
what i need to do is write a java class connecting to Data Streams given and API for it.
URI:http://<hostname>/ws/DataStream
HTTP ...
- 53
0
votes
1
answer
46
views
Add ByteArray to integer
In the following java code-snippet you'll see this line packetLengthMax += bytes.toByteArray()[43];
My question is: How does this work?
byte[] dataBuffer = new byte[265];
int packetLength = 0;
int ...
- 394
0
votes
1
answer
307
views
Android and servlet communication and displaying
I have a android app which sends the model name and String to java servlet which then adds it to a the servlets webpage's combo box. this is not happening right now, following exception is seen in ...
0
votes
1
answer
39
views
ObjectInput/OutputStream from Java to Android
I'm developing a Java SE application that does save its content as a Serializable object through a ObjectOutputStream.
My question is, reading a ObjectInputStream in a Android native app will ...
- 18.3k
0
votes
1
answer
775
views
How to read the data from datastream
Please help me out on how to read the stream of data in java. My requirement is to make the telnet connection to the router. This part is accomplished. From the router, Have to connect to the xxx ...
2
votes
2
answers
1k
views
Creating an efficient way of sending integers over a network. TCP
How can I convert integer values to byte arrays and then send them over a byte stream to the client program which converts the byte array back to an integer?
My program is a pingpong game. Once run ...
- 132
0
votes
1
answer
963
views
Understanding Data Streams and handling their exceptions
This is how I write out my file.
BufferedReader read = new BufferedReader(new FileReader(filetoreadfrom));
FileOutputStream fileStream = new FileOutputStream(filetowriteto);
...
- 106
1
vote
2
answers
285
views
Datastreams floating point Java
If the next statement is true:
DataStreams uses one very bad programming technique: it uses floating
point numbers to represent monetary values. In general, floating point
is bad for precise ...
- 13.1k
12
votes
2
answers
6k
views
Java based library for sensor data collection [closed]
I'm looking for an embeddable Java library that is suitable for collecting real-time streams of sensor data in a general-purpose way. I plan to use this to develop a "hub" application for reporting on ...
- 106k
0
votes
3
answers
633
views
Data Stream catches exception
I wrote up this class based on some examples I found online for Data Streams and I'm getting an EOFException at the end of each run. When I looked it up it said the end of the stream had been reached ...
- 67
5
votes
1
answer
21k
views
what does this mean 'Parsing a text file or data stream' and does it apply with serializables
This is my second post and I am getting used to the function of things on here now!
this is more of a theory question for computer science but, my question is what does this mean?
'Parsing a text ...
- 141
0
votes
1
answer
2k
views
Max & Min in stream of integers
Given a stream of integers (I can only go through them once), what is the best solution to find maximum and minimum? I suppose that in case I have enough time to proccess each number the easiest ...
- 65
1
vote
1
answer
1k
views
Data streaming between two processes
I have two java processes and I have to write data generated from one process as an input to the other java process. The data stream generated will be of the size of 5GB . How can I do that.
Do I ...
- 359