UDP Packet Not Receiving While Using Multicasting In Java
Jan 21, 2014import java.net.*;
public class SendConfig {
InetAddress SYSTEM_IP;
int SYSTEM_PORT = 5000;
InetAddress MULTICAST_IP;
int PORT = 6000;
[Code] .....
import java.net.*;
public class SendConfig {
InetAddress SYSTEM_IP;
int SYSTEM_PORT = 5000;
InetAddress MULTICAST_IP;
int PORT = 6000;
[Code] .....
I a simple server that receives bytes using TCP and then saves them to a file stream.Through many tests I have seen that the first packet received is always just the filename with no other data. The second packet received only has one byte and it is the first letter of the input text file. After this all packets are sent correctly, but I can't seem to figure out what is messing up the second packet. It also appears that the last packet is written twice.
Here is an example Input/Output: [URL] .....
InputStream in = clntSock.getInputStream(); //server's input stream - gets data from the client
OutputStream out = clntSock.getOutputStream(); //server's output stream - server sends data to the client
byte[] byteBuffer = new byte[BUFSIZE];
int count = in.read(byteBuffer, 0, BUFSIZE);
String firstRead = new String(byteBuffer, 0, count);
[Code] ....
Another peculiarity to me is that the second to last packet is always just "-" and then the last packet has the remainder of the magic string which terminates the file output stream.
I am aware that it is not safe to make the assumption that the file name will be sent in one go before the loop, but I wil fix that later. I am not concerned about it at all now. THe problem si that the loop should account for any amount read in, but for some reason the first packet always contains one letter, and the second packet picks up around 16000 bytes later for some reason. Why would this be?I can't edit my above post so here is the code with code tags.
InputStream in = clntSock.getInputStream(); //server's input stream - gets data from the client
OutputStream out = clntSock.getOutputStream(); //server's output stream - server sends data to the client
byte[] byteBuffer = new byte[BUFSIZE];
int count = in.read(byteBuffer, 0, BUFSIZE);
String firstRead = new String(byteBuffer, 0, count);
[Code] ....
Say I was to make a computer game, the first person to play the game would have a joinable game and would then be the server, and anyone joining in would be the client and the server was updated with JSON data of the clients computer game, and the server would then update each client of each characters new data using JSON, I would need fast multi threaded connection handling with minimum overhead, Is there a specific way to do this? or are there many?
I have realized there are a few ways to send and receive data using UDP and while experimenting I have also found its quite hard to synchronise.
Do I have a connection listening until there is data to be sent and then switched back to listening?
Do I have the server listening for a microsecond and then checking to see of there's anything to send for a microsecond continuously?
Do I have multiple connections for sending and receiving
Do I create new connections for each new and individual packets to be sent and received dynamically on a thread?
What is the optimum most effective way and do my examples reflect much understanding at all? my resent attempts create new problems and rather than re invent the wheel I would like to know what is normally done.
Keep getting a ParseException when I try to parse a ISO 8601 formatted String into a Java Date type.
String myDateString = "2014-07-04T22:59:36Z";
TimeZone timeZone = TimeZone.getTimeZone("UTC");
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'", Locale.US);
dateFormat.setTimeZone(timeZone);
Date formattedDate = dateFormat.parse(myDateString);
Keeps returning a ParseException:
Unparseable date: "2014-07-04T22:59:36Z"
What am I possibly doing wrong?
public String toString()
{
return questionText + "
";
char label = 'a';
for(int i= 0; i < answers.length; i++)
{
return "("+label+")"+" "+answers[i]+ "
";
label++;
}
}
I keep receiving the unreachable statement for line 4. I don't know why?
I am trying to connect to a local service over UDP - the simulator works fine, but my code does not... The sender is a separate thread and I have tried blocking, non-blocking, connecting, not connection, reading and re-reading the Oracle docs,
Java Code:
package my.comm;
import my.myMethods;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
[code]....
I am working on the SMS receiving using AT Commands using JAVA. i m getting the message of one page correctly using AT commands, but as i increase the size of SMS as 2, 3 or bigger pages the alphabets are converted to some thing like this
+CMGL: 0,"REC UNREAD","+923028910082",,"14/05/10,19:32:40+20"
4469616C202A3334352A393333232061757220536972662052 732E3230206D65696E20332064696E206B6120696E7465726E 65742028333030204D422920686173696C206B6172656E2120 7777772E776170747269636B2E636F6D2070657220736F6E67 73206175722067616D657320656E6A6F79206B6172656E2120 42616C616E636520636865636B206B206C7965202A39393923 206D69
Whats the problem I am not getting the right text which i have sent through my mobile phone.my function of receiving SMS is as follows :
public void send(String cmd) {
try {
outputStream.write(cmd.getBytes());
} catch (IOException e) {
[code]....
i m working on the SMS receiving using AT Commands using JAVA. i m getting the message of one page correctly using AT commands, but as i increase the size of SMS as 2, 3 or bigger pages the alphabets are converted to some thing like this
+CMGL: 0,"REC UNREAD","+923028910082",,"14/05/10,19:32:40+20"
4469616C202A3334352A393333232061757220536972662052732E3230206D65696E2
0332064696E206B6120696E7465726E65742028333030204D422920686173696C206B
6172656E21207777772E776170747269636B2E636F6D2070657220736F6E6773206175
722067616D657320656E6A6F79206B6172656E212042616C616E636520636865636B2
06B206C7965202A39393923206D69
Whats the problem i m not getting the right text which i have sent through my mobile phone.
My function of receiving SMS is as follows :
public void send(String cmd) {
try {
outputStream.write(cmd.getBytes());
} catch (IOException e) {
e.printStackTrace();
[Code] .....
Here's my code:
System.out.println((3 / 1.5) + 42(3 + 3));
I don't understand what I'm doing wrong. I'm receiving these errors:
PrintFunction.java:8: error: ')' expected
System.out.println((3 / 1.5) + 42(3 + 3));
^
PrintFunction.java:8: error: not a statement
System.out.println((3 / 1.5) + 42(3 + 3));
^
PrintFunction.java:8: error: ';' expected
System.out.println((3 / 1.5) + 42(3 + 3));
I'm using Sublime Text and JDK 8.
My program is reading my file, but its printing out weird cryptic numbers instead of the 1-10 that is in the file. But it uses the numbers in the file to get the Max Value and Total. Also I am receiving 0 for my Minimum Value but, 0 isn't even in the file, my lowest value is 1.
Java Code: /*
* Student Name: Irrelavent
*
* Description: This program will read from a text file and display its contents in an array format as well as the average of the numbers and the minimum and maximum value within the array and it will display the total of all the numbers added together.
*
* Input Variables:
*
* Desired Output:
* Total: 55
Average: 5.5
Minimum Value: 1.0
Maximum Value: 10.0
The data being used is: [1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0]
*/
[Code] ....
Output:
Numbers being used: [[I@55f96302]
---------------
Max Value: 10
---------------
Minimum Value: 0
---------------
Average: 0.0
---------------
Total: 55
I want 1 for my Minimum and I want 5.5 for my average, when I make 'average = total / numbers.length;' ---> 'average = total / (double)numbers.length;' I get 0.55. Also, as its obvious, my 'Numbers being used' section is messed up and I don't know whats causing this.
I am working on a program that simulates a bug moving along a horizontal line, My code works correctly when I test it in it's own class but when I tried testing my constructor and methods in a test class I received an error saying, "package stinkBug does not exist" on lines with my methods. However, stinkbug is not a package.
Java Code:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
[code]....
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I tried both options using NetBeans but I'm getting errors everywhere starting with the library import. I'm pretty new to Java so I'm sure I'm missing a lot of things here. I pasted the code below from the OpenScript framework that want to use in a stand-alone file for your reference.,
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[Code] ....
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the compiler created the directory: /home/user/src/com/myfirm/program and put all of the .class files in there.So how do I get the program to run? if I run from /home/usr/src
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package MyProject;
import java.io.IOException;
import java.io.InputStream;
public class Cmd {
public static void main(String[] args) {
try {
final Process process = Runtime.getRuntime().exec("start "" /D "C:Riot GamesLeague of
[code]....
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