Save upd packets in textfile problem

Programming Questions

mataarsak

Save upd packets in textfile problem

in Programming Questions • 1 year ago

this is a part of my code it receive some udp packets an I want to save that in a text file , but I think something is wrong because it does not work , probably because it receive tha packets gradually and it's not like normal that we have an array of strings already

void receive(byte[] data, String HOST_IP, int PORT_RX) {
int j = 0 ;
while ( j<10 ) {
if ( data[2*j+2] >= 0 ) {
String bin2 = str((float)unbinary(binary(data[2*j+3])+binary(data[2*j+2])+binary(data[2*j+1])+binary(data[2*j]))/100);
String[] words = split(bin2, ' ');
saveStrings("nou.txt", words);

when I try to print word string it looks like this :

[Ljava.lang.String;@405cce38
[Ljava.lang.String;@4058a428
[Ljava.lang.String;@4056fd98
[Ljava.lang.String;@40574a58

why it's printing in this strange format?

I also tried this :

try {
while ( data != null ) {
output = createWriter("c:/file.txt");
output.println("1");
output.flush();
output.close();
print("finish");
}
}
catch (Exception e) {
println("error:");
}

java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at hypermedia.net.UDP.callReceiveHandler(UDP.java:677)
at hypermedia.net.UDP.listen(UDP.java:574)
at hypermedia.net.UDP.run(UDP.java:606)
at java.lang.Thread.run(Thread.java:1019)
Caused by: java.lang.ArrayIndexOutOfBoundsException
at changethispackage.beforesubmitting.tothemarket.udp1.udp1.receive(udp1.java:47)
... 6 more
[12-06-14 10:14:15.951 +0000] receive packet <- from /192.168.0.23, port:2026, length: 96
error:
error:
error:
error:
error:
error:
error:
error:

Replies(3)

PhiLho

Re: Save upd packets in textfile problem

1 year ago

" why it's printing in this strange format?"
Because you don't use Processing's println()?
Compare the two outputs:

String[] w = split("a b c", " ");
println(w);
System.out.println(w);

Java arrays have no toString() method, so Java just dumps the type ('[' means array, 'Ljava.lang.String' is the type of the array, @stuff is the reference in memory of the object).
Processing's println() recognizes most array types and print them out smartly.

I am not sure if the ArrayIndexOutOfBoundsException comes from the code you show... It has no arrays!

mataarsak

Re: Re: Save upd packets in textfile problem

1 year ago

here is my code :

void setup() {
size(400, 400);
udp= new UDP(this, PORT_RX, HOST_IP);
udp.log(true);
udp.listen(true);
super.start();
}
void draw() {
background(0);
rect(bin[0], bin[1], 5, 10);
}
void receive(byte[] data, String HOST_IP, int PORT_RX) {
int j = 0 ;
float[] bin = new float[(data.length/2)];
while (j < data.length ) {
if ( data[2*j+2] >= 0 ) {
String unhx =(binary(data[2*j+3])+binary(data[2*j+2])+binary(data[2*j+1])+binary(data[2*j]));
float unbin = ((float)unbinary(unhx)/100);
bin[j/2] = unbin;
print((j/2) + "is" + bin);
}
else if ( data[2*j+2] < 0 && data[2*j+3] < 0 ) {
data[2*j] = (byte)(-data[2*j]);
data[2*j+1] = (byte)(-data[2*j+1]);
String unhx =(binary(data[2*j+1])+binary(data[2*j]));
float unbin = ((-1)*(float)unbinary(unhx)/100);
bin[j/2] = unbin;
print((j/2) + "is" + bin);
}
j = j + 2;
}
}

I have a loop so I don't know exactly where should I put saveStrings() , because in the next iteration , saveString will clear the textfile and save new items into that .

and ArrayIndexOutOfBoundsException error is in this code too . this is the complete code that I wrote .

please look at this topic also , thanks so much

PhiLho

Re: Save upd packets in textfile problem

1 year ago

Two ways:
- Use your createWriter, but open the file in setup() and close it when you exit the sketch. Enlarge the scope of your operations, as long as you narrow it to the receive operation, it won't spawn several calls.
- Or put your arrays in an array list ( ArrayList) and when you need to save, convert all this data into a single array of strings and save it. Again, the scope of the array list must be global.

The ArrayIndexOutOfBoundsException occurs because you limit j to data.length/2, but you try to access data[2*j+2] which is beyond the limits at the end.

Top Reply