Networking :: Socket Creation Too Slow Versus URLConnection
Oct 27, 2014
I'm trying to write a transparent proxy like polipo. Polipo is written in C and I want to have the same result in java.
A simple program that can filter/monitor all connections created and closed by the browser.
To do so, I've chosen to work with sockets, because that's the only way i know to read and write raw data to and from the browser in a completely transparent way.
In this moment my code reads and writes every couple of request/response but I've noticed profiling it that the time needed to create the socket is a bottleneck.
Using URLConnection to create the same connection I need much less time than sockets.
When socket creation implies 50ms URLConnection implies only 1ms.
We have a servlet application running under jboss 7.1.1/java 1.7 that sends http requests to another server. Everything works fine for most of the time, but occasionally (from one to a couple of times a day) we get a “Socket closed” exception. I’ve been trying to find out what might be causing this but so far I’ve been unsuccessful. By the way, this has been happening while the application was running under older versions of Jboss/Java so the version might not be that relevant.
Here’s an excerpt from the method where this happens: . . . . . try { HttpURLConnection conn = (HttpURLConnection) urlEndpoint.openConnection(); conn.setRequestMethod("POST"); conn.setDoInput(true); conn.setDoOutput(true);
[Code] ....
And here’s what the exception looks like: . . . . . . java.net.SocketException: socket closed at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(SocketInputStream.java:150) at java.net.SocketInputStream.read(SocketInputStream.java:121) at java.io.BufferedInputStream.fill(BufferedInputStream.java:235)
[Code] ....
In my investigation I came across some posts that were mentioning the sockets pool the http connection is keeping, but I’m not sure whether and how this solve the problem I have.
I've been trying to send a file(text & image files) from one system to another. somewhat I did, but file is not send originally in destination system. It shows AccessDeniedException on the destination system. What should do to avoid this exception.
I am learning JAVA and understanding some of its specific oddities. For example I notice that JAVA loves instances but not variables.
In Python: x = 1 y = 2 print(x,y) yields (1,2)
then I do y = x and print getting (1,1)
This makes sense to me since x and y are variables and thats how variables work. In JAVA I notice this script:
public class TESTRUN { public static void main(String[] args) { int x = 0; int y = x; System.out.printf("x = %d, y = %d %n", x, y); x = 9; System.out.printf("x = %d, y = %d", x, y); } }
This yields: x = 0, y = 0 x = 9, y = 0
So I get that JAVA doesn't understand variables? Or only takes instances of variables? Is there any way to yield a true variable or you always have to update variable relationships?
Viewing this example of pagination [URL] and other similar beans for pagination, why do they do these beans view scoped? These beans dont contain any properties for a form so they could be application scoped, right?
We are using an applet in our web application. The applet of our application is dependent on bouncycastle jar,bcprov-jdk15.jar and few other jar's whose size comes around 4 mb. When using the appliaction on jre7, the applet is taking too long time to load than usual time. Is there any way to place these jar's in client machine? Will it improve the performance? Is there any other way to reduce the loading time of applet apart from placing jars in client machine?
I've recently tried to write a file parser for the .x3d file type as it's one of the few 3d model types I can find written in easy to understand (and interpret) English. While it technically does work (or what I have so far), the issue is that it takes far too long (17 minutes) to parse just a part of the file (the vertices of the model).This is the code for the object itself:
import java.io.*; import com.sun.j3d.utils.geometry.*; import javax.media.j3d.*; import javax.vecmath.*; public class ModelLoader { BranchGroup object = new BranchGroup(); BufferedReader reader; String line = "start";
[code]....
Anyway, here are some observations I've made about the file:
-The line in the file itself that contains all the vertices is all one giant string according to the file. -There are apparently 18,000 vertices in all (according to the command at line 18). -Unless Netbeans automatically terminates infinite loops after a certain amount of time, it is most definitely NOT an infinite loop as I have seen the program terminate on its own (after 17 minutes, though).
I had a theory that maybe organizing each vertex into its own line and then having the program switch to the next line when it's done reading that vertex might make the program run faster, but I'm not sure why it would, so I thought I'd come here in case that theory turned out to be a dead end.
I'm currently taking a computer science class but the class is moving extremely slow and I'm not learning much, so I've started to program on my own. The most recent project I've done is a tic tac toe game, and I'm looking for something else to do now. I can do with an increased difficulty from this project, but not extremely difficult.
I have a large scale enterprise application (5 modules) project using RAD, WAS v7, Java EE 6 (EJB 3.1, JPA), ZK framework.
The project is using RAD as IDE. The problem is that it takes too long to deploy (more than 5 min) when changes are made to the EJB's (although the changes are minor in only one file) but when changes are made to zk framework (the web & presentation layer), it is fast to deploy.
Don't know what cause the problem. Is it because of EJB 3.1/ JPA or RAD/ WAS?
Is it happening in other IDE or applcation server also?
I have a code below that is reading large image size and writing them to file however the process is too slow. how can i refine this code in such a way that it will work faster?
I have a code below that is reading large image size and writing them to file however the process is too slow. how can i refine this code in such a way that it will work faster?
I am working on a Java Streaming Networking ( Client Serve ) project , among remote client can:
1 ) chat,
2 ) Share files,
3 ) Share Screen live streaming,
4 ) Access the remote system.
All are working well faster & live on networking. But if i host on the Hosting server the all process are working but in deadly slow streaming is not live..,
I have been using JavaFX for some time now and have encountered many performance issues, mainly with the initial display of GUI elements. For example, a simple stage with a table view (with about 10 columns) and chart takes about 5 seconds to display. A color picker will take about 3 seconds from the time I click the control to when it displays the pallet. This only happens when the controls are first displayed. This can't be right. I have searched and none seems to have a similar problem so I thought I would ask here just to make sure. Here is a sample Hello world that shows the problem with the color picker (takes ~ 3 seconds to show pallet when clicked).
public class HelloWorld extends Application { @Override public void start(Stage primaryStage) { StackPane root = new StackPane(); ColorPicker cp = new ColorPicker(); root.getChildren().add(cp);
Visual effects such as Transitions perform very poor on linux "wheezy" compared to windows. I noticed this on different PC's, checked for Java7 and Java8. If the UI contains many objects then the transition sometimes does not even appear.
I do not think this is graphic card related since videos play quite ok.
I use the default ATI driver without Xorg.conf file and installed the xcompmgr
and tried several options, such as
Option "Composite" "Enable" or Option "backingstore" "true" Option "AllowGLXWithComposite" "true"
This did not speed up things, are there other things that I could do to improve the performance ?
So I'm working on some networking code and I have the Server running as its own thread, then I have a PacketListener which is contained in the Server, that is running on its own thread too. As of right now, the PacketListener waits for packets via DatagramSocket.receive() and then adds them to a queue. The Server runs in a loop and it checks that queue for packets and then polls the most recent and process it before sleeping for 1 millisecond. Here is my question though, I'm considering changing the program to a more observer pattern structure in that when the PacketListener would receive a packet, rather than add it to the queue, it'd notify the server which would process it. However, wouldn't this cause additional time required within the PacketListener thread dedicated to processing the packets rather than listening for them?
I am trying to create a Android game. The game is a card game, where each card has a different action and has a different effect. My first thought was to create a Card class and somehow dynamically change the action method for each instance. However after a little bit of research it seems that may be too difficult. A different idea is that I create a class for each different card, and therefore can define the action method different for each one. However currently there is at least 300 cards and therefore I would need 300 different classes, which seems excessive.
I'm making a code for a log in system that allow me to verify if username and psw are correct (using a file txt as refer), and then i will add maybe the possibility to sign up.
The fact is that I want this kind of formatting on the .txt
username psw username psw username psw
...etc
So I have to read the lines and split to the " " and compare the insert data and the read data.
Here is my code, it star but give me this error when i insert any word
XML Code:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 1 at prova.main(prova.java:20) mh_sh_highlight_all('xml'); Java Code: import java.io.File; import java.io.FileNotFoundException; import java.util.Scanner; public class prova { public static void main(String[] args) throws FileNotFoundException {
So, I've been working on creating a text-based game engine that would create games similar to Achaea. It's been working pretty well so far. I just finished creating a great mapping system, but now I've run into a problem. I have a mapping system, but actually creating a map would prove to be quite a lot of work. Each location that the player can be inside of has a name, description, map symbol, and an array of the things inside of it. How can I make some sort of map creation program or something so that I can create my maps more easily?
I thought perhaps making a constructor that accepts a list of files, the first containing a table of strings for the names, the second containing a table of strings for the descriptions, etc.; but it seems that would be quite tedious and may be more complex than actually just hard-programming maps.
I have just started to learn Java and have come across a small bump in the road, In the book I am reading it shows an example program using java.io.File with the line File javaFile = new File("test.txt");
The program then goes on to ask if you would like to delete the file with a small do while loop.
Anyway, try as hard as I can I cannot located the test.txt file on my system! is there a reason for this? The program runs fine and has no errors and if I manually create the txt file it will delete it, but it doesn't seem to create the file in the first place.
I have a requirement to get the details of the files present in a directory on a server. I need to get the file names and timestamp. I have the below code to get the file names:
Connection conn = new OracleDriver().defaultConnection(); ArrayDescriptor arraydesc = ArrayDescriptor.createDescriptor ("DIRLIST_T", conn); File myDir = new File (dir); String[] filesList = myDir.list(); ARRAY dirArray = new ARRAY(arraydesc, conn, filesList); return dirArray;
But am not able to get the timestamp. How can I get the timestamp as well.
