I would like to limit my bandwidth usage when accessing/downloading files (similar to the --limit-rate 50K option for curl and wget) as the website has limited bandwidth. I am not exactly sure how to implement this, but I'm guessing it be accomplished via the BufferedReader? I have attached the current code below.
import java.io.OutputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
[Code]....
I was asigned to make a code that would limit the input to 1 character when asked for the initial of your middle name. So far I have the code ask for your first name then your last name and out put "Hello" firstname+last name. Im trying to add an 1 character middle itnitial in there.
View Replies View RelatedI defined a java class thus:
class Info{
public String name;
public String version;
public String arch;
double CPUSpeed;
double ranUtil, CPUUtil;
};
But each object of such a class takes many bytes. How can I limit it to one fourth of a Kilo-Byte?
I want to get current Computer CPU usage of my computer and display it in Console View of Eclipse? How can I achieve this?
My template code is:
Java Code: public class GetCPUUsage{
public static void main(String[] args){
System.out.println("CPU USAGE IS: ??????");
}
} mh_sh_highlight_all('java');
I added ??? as placeholder for CPU usage because I do not know how to retrieve RAM usage by Java.
I have a class as shown below. This class has a method addFilter with 2 parameters (type String and type Command1 )
public class Command1 {
public StringBuffer addFilter(String query, Command1 dataBase) {
//concrete implementation
return query;
}
}
I have another class Command2. Here I need a similar method. The only difference is in the type of parameters passed. (type String and type Command).
public class Command2 {
//TO DO:
public StringBuffer addFilter(String query, Command2 cmd) {
//concrete implementation
return query;
}
}
I have started by using Interface
public interface Helper {
public StringBuffer addFilter(String query, XXXXX parameter2);
}
I would like the classes Command1 and Command2 to implement the interface Helper and override it these two public classes.
However my problem is in dealing with the 2nd parameter. Am I right in my approach? How do I handle this issue?
I created an instant messenger using java. When I have the Server that communicates between the clients and one client running on my Computer the CPU Usage is at 100%. It really slows down everything else I'm doing and I figure this might be an issue if I gave this to people to use. I don't want the client taking up a lot of CPU Usage if they're just running it in the background while doing other things on their computer. The program utilizes multithreading. Each thread is constantly being polled for input.
The Server, as seen below, has two threads. I explain what the threads do before the code. There is also another while loop running constantly in the server that is waiting for sockets to connect. The loop does not run constantly at the line socket.accept(); it stops and just waits.
The User, split into a menu and chat window, has two threads as well. I explain what the threads do before the code. After I originally posted I put a 100 ms sleep in all my threads. CPU Usage is still at 100%*
This thread listens for input from the user. The input tells the server what action to take. There is a thread running for every user currently connected to the server.
public void run()
{
try
{
input = new DataInputStream(user.getSocket().getInputStream());
output = new DataOutputStream(user.getSocket().getOutputStream());
[code]....
What is the usage of garbage collector in java.
View Replies View RelatedDeclaring the method as static precludes one from using any sort of object oriented programming, thus the method cannot access instance fields of the object if it needs to.
I created two short classes to sort of find out what this meant, but I feel I do not understand it well enough.
Test class (main):
package votek;
public class Test {
public static void main(String[] args) {
SomeMethod();
}
public static void SomeMethod() {
Character character = new Character();
character.totalLevel = 50;
System.out.println(character.totalLevel);
}
}
Character class:
package votek;
public class Character {
private int level = 0;
public Character() {
level = 50;
}
}
OR
Does it mean that making a static method in the class with private instances will prevent the method from using the private instances?
I've spent almost 3 hours on googling about java beans and where it is usable. What I've figured out is that a bean has a public non-arg constructor, properties and getters/setters to manipulate them. I also know that a bean contains no logic, only fields. However, I don't fully understand why I need to use beans instead of normal classes even if a class can do the same things like a bean? Are beans used to store data or what?
View Replies View RelatedWe have a webservices application that uses Java 1.6.0_43, Spring 3.2.3, CXF 2.6.9 and deployed to Jboss 5.0.1 GA in a LINUX x86_64 centos box. It essentially uses apache httpclient (4.2.2) to call internal services and returns the results back to customers. The application has been running fine for a year or so until early this month when all of sudden, it loaded about 300K classes in a very short time during our regression tests and saturated the CPU usage ever since. Hence the application is no longer responding.
I have been trying to troubleshoot the problem for a while. Tried visualvm, dynatrace. thread dumps. heap dumps... None of them is very effective in capturing what are the classes that are loaded so many times and what path triggered that.
When it comes to Java EE I see many developers having trouble with the usage of transactions and exceptions and when to use what.
I see a full chapter of RESTful Web Services, but do you also relate these Web Services to their counterparts (SOAP Web Services)?
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?
View Replies View RelatedI found this method from the same link from which I found the Pandigital method. This method uses the algorithm of sieve of eratosthenes who was a greek mathematician and showed how to find prime numbers by taking an individual number and finding the multiples of it and cut them out for they will not be a prime number. From what I've seen this program gives the results much faster than the traditional way of searching for prime numbers by diving that number by the digits upto half of that number and check for divisiblity.
Well, here's the code
public int[] ESieve(int upperLimit) {
int sieveBound = (int)(upperLimit - 1) / 2;
int upperSqrt = ((int)Math.Sqrt(upperLimit) - 1) / 2;
BitArray PrimeBits = new BitArray(sieveBound + 1, true);
for (int i = 1; i <= upperSqrt; i++) {
if (PrimeBits.Get(i)) {
[Code] .....
As seen from the full program on the site [URL] .... this program was formely writen in C++ and from there I've scrapped out this method as the syntax are corresponding to that of Java, but one problem I faced was in finding the BitArray class in Java. I was unable to understand the approach of this program to find the prime numbers.
When a JavaScript client attempts to open a socket, instead of the connection opening it immediately closes. The client is using:
webSocket = new WebSocket("ws://localhost/example");
The same thing happens for com.sun.net.httpserver.HttpsServer where client is using:
webSocket = new WebSocket("wss://localhost/example");
How can I enable websocket support?
If it's not possible, how can I request for it to be added as a new feature?
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.
I have noticed an error, that makes sometimes troubles, when downloading jars from https addresses, when there are many jars to download..
Best example is by opening Javas on Java version checker. [URL] ....
I get also following log...
network: Connecting https://www.java.com/jsp_utils/jreverification.jar with proxy=DIRECT
network: Connecting http://www.java.com:443/ with proxy=DIRECT
network: Connecting https://www.java.com/jsp_utils/jreverification.jar with cookie "JSESSIONID=22ABBA2BE9B5789629C276AC35BDF969; s_cc=true;
Even if the address is https, java try to access via http protocol on port 443, and that leads sometimes to problems..
I have noticed this, when I have used URLConnection(HttpURLConnection) for my self, as soon Java sends http link on https address, the jar gets sometimes not loaded, and i get error about missing class that get called..
On http addres it is not so bad, since same protocol is used, but evidently, that is evil for https..
As you see, that happens already when loading Jar by Applet Starter and at all, it happens each time on any URLConnection
###############################
Java Plug-in 10.13.2.20
Using JRE version 1.7.0_13-b20 Java HotSpot(TM) Client VM
User home directory = X:Usersadmin
----------------------------------------------------
c: clear console window
f: finalize objects on finalization queue
g: garbage collect
[Code] .....
I want to get current RAM usage of my computer and display it in Console View of Eclipse? How can I achieve this?
View Replies View RelatedI wrote a proxy in java. The version with ServerSocket-Socket/Stream-IO works wonderfully. When I rewrote it to ServerSocketChannel-SocketChannel/ByteBuffer it works also very well. However, when I access YouTube things happen weirdly: The video is frozen after 3 or 5 minutes (but this did not with the version of ServerSocket/Socket). I strongly assume that there probably was a nasty bug.... The (shortened) codes are:
Server:
public class BeanServer extends Thread {
public BeanServer( ) { }
public void run( ) {
try {
bServer = ServerSocketChannel.open();
[Code] .....
My application with Oracle Database only works with Ethernet, I tried to connect via wireless without any response. When I run the command netstat the port state is WAIT TIME and then be closing. The clients machines run Windows 7 and 8 and the server run Suse Linux Enterprise Server 10 SP2, if the client machine run XP all works fine. I disabled the firewalls in the both sides.
View Replies View RelatedWe 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 am trying to create a new text file in FTP Server using FTPClient but im not able to do. By using storeFile method i can only upload file that is already exists in my local system. But my requirement is to create file directly into FTP Server.
View Replies View RelatedSimilar to HttpFilter (javax.Servlet.Filter ) which when added in web.xml can intercept any incoming request to JVM / outgoing (as response) independent of framework ( Spring/CXF/Jersy etc ) without any code changes (excluding the filter itself), I am trying to find an API or approach which could intercept any outgoing HTTP calls from JVM to add/modify headers independent of framework.
Quite often the word Outgoing HTTP call is misinterpreted in the forums so let me explain with example.
Let us assume there are two JVMs, jvm1 and jvm2. and there are HTTP calls being made from JVM1 to JVM2. I would like to intercept the HTTP connection being made from JVM1 to modify the headers information before the call happens. I do not want the code to be tied to a specific framework so that I can as bundle the interceptor as a jar and share it with application team. Changes in web.xml is fine.
I'm facing some problem connecting to a IBM 4690 OS Server with the FTPClient class from the commons-net-1.4.1 library. It seems it can't read the folder on the server. The problem is that using the FTP client from Internet Explorer is works perfectly.
Here is my code (kind of hardcoded but it's only to test).
FTPFile[] files = null;
try {
files = listFiles(remoteFolder);
} catch (ParserInitializationException e) {
[Code] ...
Here is the ParserInitializationException that it throws:
org.apache.commons.net.ftp.parser.ParserInitializationException: Unknown parser type: OS 4690 operating system
at org.apache.commons.net.ftp.parser.DefaultFTPFileEntryParserFactory.createFileEntryParser(DefaultFTPFileEntryParserFactory.java:118)
at org.apache.commons.net.ftp.FTPClient.initiateListParsing(FTPClient.java:2358)
at org.apache.commons.net.ftp.FTPClient.listFiles(FTPClient.java:2141)
...
I've tried to use many of the FTPFileListParser available but without success. How could I handle the problem? Where could I find a Parser that would works?
I am trying to remotely call one servlet and getting below exception:
java.io.StreamCorruptedException: invalid stream header: 3C21444F
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:785)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:282)
at com.deere.isg.dm.web.controller.StatsController.getOtherAdminStatsBeanFromConnectURL2(StatsController.java:224)
at com.deere.isg.dm.web.controller.StatsController.main(StatsController.java:122)
As per my program i am just simply calling this:
URL url = new URL(controllerPath + STATS_PATH);
httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("GET");
httpURLConnection.connect();
inputStream = httpURLConnection.getInputStream();
objectInputStream = new ObjectInputStream(inputStream);
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.
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.
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