I have to build a server application. My issue is that it can never shutdown/restart. But I still need to update it.After some research I learned about OSGI where I can add/remove a bundle of code while the application is running. (update to a new version)Can I use JavaWS to update my OSGI application without having to close and restart it? I'm new to OSGI/JavaWS.
View RepliesI am trying to create an array list without using the built in arrayList class that java has. I need to start the array being empty with a length of 5. I then add objects to the array. I want to check if the array is full and if not add a value to the next empty space. Once the array is full I then need to create a second array that starts empty and with the length of the first array + 1.
The contents of the first array are then copied into the new array without using the built in copy classes java has and then the new array ends up containing 5 elements and one null space the first time round. The first array is then overwritten with the new array containing the 5 elements and the null space. The process then starts again adding values until the array is full which will be 1 more value then recreating the second array empty and the length of the first array + 1. This is my attempt at creating this but I have run into multiple problems where I get only the last value I added and the rest of the values are null:
public class MyArrayList {
public Object arrayList[];
public MyArrayList(Object[] arrayList) {
this.arrayList = arrayList;
[code]...
I am writing a custom jnlp installer for downloading our applications. We are having difficulty to specify our own cache directory. The default Download Service is not taking the below property. I was wondering if we need to extend any of the jnlp api classes and write my own. System.setProperty( "deployment. user.cachedir", "C://Users//f355668//AppData//Roaming//WorkBench//" );
View Replies View RelatedTo insert 500 records into oracle my code is taking more than 1 minute.
I am using the below:
1) dbcp connection pool
2) Jdbc, autocommit off
3) preparestatment
4) batchupdate
5) deployed in fuse servicemix
Important thing : Table doesnot have index.
How to improve the performance. Below is the code snippet..
// Added for Transaction
conn.setAutoCommit(false);
conn.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE);
PreparedStatement dataStmt= null;
dataStmt= conn.prepareStatement("insert statement");
for (Value value : valueList){
[Code] .....
I am looking for a way to compile Java Source-Files at runtime and save them all in an executable jar; almost like an IDE would do. I know that there is the javax.tools package which provides a JavaCompiler interface and you can use ToolProvider.getSystemJavaCompiler() to get an instance of a compiler. However, this method has one important problem: it only works on machines that have the JDK installed. Not when only the JRE is installed.
I guess at this point that I need some kind of third party library that offers an implementation of a JavaCompiler. Unfortunately, this is really complicated to search for on the internet since all top listings when searching "compile java at runtime jre" do not really provide a solution to the problem.
I am writing a (somewhat) complex simulation software right now which is supposed to be used by people who have absolutely no knowledge of programming. At the same time, this software should provide the user with a certain amount of flexibility and control over the flow of the simulation.
My previous take on this problem was to build a complex system to interprete user settings from a GUI. I would basically read the GUI input, output it to some kind of own scripting syntax which I just quickly made up and have that interpreted at runtime. Then I realized, that is a silly concept and I threw it out before I got far into the developement.
The much better solution I came up with is taking the input from the GUI, create java source code from it and compile it at run-time. Seems much cleaner and nicer to me; will also probably have a better performance, but thats not really an issue anyways.
While executing my application i came across with this unexpected error which i don't know why?
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000007fdcacd79a9, pid=4980, tid=7724
#
# JRE version: Java(TM) SE Runtime Environment (7.0_45-b18) (build 1.7.0_45-b18)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (24.45-b08 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C [ntdll.dll+0x79a9]
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
#
# If you would like to submit a bug report, please visit: [URL} .....
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#
We are shipping in our company the JRE bundled with the client application in order to ensure the compatibility. But when upgrading from jre6 to jre8 the size increased by 50 MB!
Is there a reliable and secure way to reduce the footprint of the JRE? Are there "light distributions" or a list of libs/files that can be safely removed?
I will detailedly explain my requirement below,. I am going to automate a manual process. I will be reading multiple CSV files from a remote location using java.There are five formats of input files are expected, each differs in their header structure. For example, Type 1 - Number, ID, Name, Phone, Address...Type 2 - Number, GID, Employee Name, Address1, Address2, Phone number and so the other three types are also differs.
The precondition is not all the files are expected for a particular run. I need to read these files one by one, validate it, log the validation error and i have to consolidate all the correct data from all the files together in a standard output format, in a single file The standard output format will be like,Number, Name, ID, Address
I need to have the above data alone in the output file and rest of the data can be ignored.What i have tried is as follows, I have created 5 bean classes representing each type's header. I just read an input, identify its type and parsed it. I parsed line by line.
public String[] parseCSV(String inputLine){
try {
String[] fields;
Pattern p =
Pattern.compile(",(?=([^"]*"[^"]*")*(?![^"]*"))");
fields = p.split(inputLine);
/*for ( int i = 0; i < fields.length; i++ ) {
System.out.println(fields[i]);
}*/
[code]...
I have validated as per the validation rules and i appended each line elements into an object. I have added all the objects in to a MAP collection. Likewise, i have created 5 beans and did the same.But, what is the change needed now is,. All the headers in all the five types of rosters are configurable items. hence, i have to change my bean classes everytime when the header structures are changed.
We have to create one single utility, which is configurable for all the five types of input files. To be very clear, if type 1 input comes with 8 columns and type 3 comes with 12 columns, the utility is able to parse it.
We are going to have a table which has the data regarding the header structure of all the five types of inputs alone. Once i read a file and identify its type, i will hit the database and read the header structure of that particular type and its column count. I will match the column count with the input file's header count and i will have to proceed creating a bean class on runtime depending upon the header structure read now. I will validate and consolidate as i did above. The requirement is, Runtime configuration of bean class, depending upon the type of input.
i have a run time error that could not find or load the main file java .
View Replies View RelatedI was having trouble running some Java programs (not my own) in Windows XP, and in the process I uninstalled and installed JRE versions 6, 7, and 8, one at a time, probably in the order 7, 8, 7, 6, 7. The program that had the original problem only worked in V6, but some other programs stopped working. I went back to V7, and those other programs still didn't work. The message was "the registry refers to a nonexistent java runtime environment installation". The only advice I could find with Web searches was to reinstall the JRE. Needless to say, that didn't work.
So I looked at the registry, and I found that there were still references to V8, which had been uninstalled. The first was
HKEY_CLASSES_ROOTjarfileshellopencommand - (Default) = "C:Program FilesJavajre1.8.0_31binjavaw.exe" -jar "%1" %*
The folder re1.8.0_31 doesn't exist, so I changed it to jre7. That didn't work.
Then I found
HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment - CurrentVersion = 1.8
I changed this to 1.7, and deleted some following entries such as
HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment1.8 - JavaHome = C:Program FilesJavajre1.8.0_31
retaining entries such as
HKEY_LOCAL_MACHINESOFTWAREJavaSoftJava Runtime Environment1.7 - JavaHome = C:Program FilesJavajre7
That worked!
So, there is a bug in the installer(s): if you uninstall V8 and install V7, the 'CurrentVersion' isn't set correctly, with the result that the registry points to a non-existent folder. The V8 uninstallation should delete these entries, or the V7 installation should change them.
I have a strange behaviour when trying to update a bean. Here is the edit page:
<h3>Edit Post</h3>
<div class="row">
<h:form>
<div class="small-3 columns">
<label for="right-label" class="right inline">Title</label>
[Code] ....
Here is the bean class:
package com.airial.controllers;
import com.airial.domain.Post;
import com.airial.service.PostService;
import com.ocpsoft.pretty.faces.annotation.URLMapping;
import com.ocpsoft.pretty.faces.annotation.URLMappings;
import org.springframework.beans.factory.annotation.Autowired;
[code]...
postToUpdatet is always NULL. Why the title property is not binded ? What is wrong here ?
I have installed and tested j2se jdk8 u5 on my Windows 7 64 bit laptop and successfully tested in Eclipse with a quick Hello World.
JAVA_HOME = C:Program FilesJavajdk1.6.0_25
When I try to install j2ee jdk7 sdk7 I get
Error: Could not find the required version of the Java(TM) 2 Runtime Environment in '(null)'
I am using java process to start a system command in windows
Runtime r = Runtime.getRuntime();
Process pr = r.exec(cmdString);
I want to get the prompt out put from cmdString = "cmd /c type fileSmallSize"->>>> It is ok the have the content of the file when file is small.
However, for a large file java process will hang and no Exception occurred, what is the problem?
The easiest testing you can try on the logging.properties file in java.
public static String executeCmdAndReturnPromptResult(String cmdString)
throws Exception {
LOGGER.entering(CLASSNAME,
"Entering executeCmdAndReturnPromptResult()", cmdString);
String cmd = cmdString;
[Code] ....
It seemed to me that the bufferSize is limited so that I can only have it less than a default one, how to increase it?
My question now is how to increase the size of buffer in order to read a larger InputStream ?
BufferedInputStream() default size is
private static int defaultCharBufferSize = 8192;
private static int defaultExpectedLineLength = 80;
How to make it larger and working? I tried to increase the defaultCharBufferSize to 500000000 but it did not work!
I'm trying to make a update page where you search for person info by their number then have the ability to change any info and save it back to the binary field. I have the search working but i don't know how to do the update,.here my code:
Java Code: import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.EOFException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
[code]....
I have a GUI with several buttons and I'm using NetBeans GUI Builder to do. At the click of one of these I would like for it to open another frame containing a picture. So I associate a listener (actionPerformed) the button and when clicked it opens actually post the new frame.
In the new frame I waxed a JLabel and then I associate the image of the label. I saw that to do that NetBeans generates this code:
label.setIcon(new javax.swing.ImageIcon(getClass().getResource("/img/tree.png")));
My problem is that the picture is overwritten several times during the execution of the program is not changed yet in the frame. That is, in the new frame is always displayed an old version of the image.
I have an image that is created every time I click on the button (it always has the same name and same path). Basically I have a generic tree on which I perform the operations (add, remove, etc..). When I click on the button I call a method that generates the image of the tree (using Graphviz). So I have one image that changes over the time...
How can I do so that the image is always up to date?
The Code:
package View;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
public class AlberoIpotesi extends javax.swing.JFrame {
[Code] ....
I have a flat file (.txt) with contents in a predefined format. I need to parse and look for a particular content and update it. How can i achieve this using Java.
View Replies View RelatedI have been developing the web applications using struts (J2ee Technology) and i have developed few web applications and send to the production. now i want to add auto update capability of the application, means if any changes was made jsp/action class then application must have capability of updating the new code.
View Replies View RelatedI am developing my first Java application and the database I use is MySQL. I have created two separate buttons; one to insert new data into my database and the other to update the database when changes are made.
Each button is working perfectly, but I now want to combine both functions into just the save button. Thus, whether I am entering new data or modifying existing data, the save button should use an IF ELSE condition to decide whether to use the INSERT or UPDATE command.
My problem is, how do I write this IF ELSE statement? What should be the condition? For example;
IF(what? ){
String sql ="Insert into Table1 (classID,className,counselorID,startDate,endDate) values (?,?,?,?,?)";
}ELSE{
String sql2 = "update Table1 set classID = '"+value1+"',className='"+value2+"',counselorID='"+value3+"',startDate='"+value4+"',endDate='"+value5+"'
where classID = '"+value1+"'";
}
Server:
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
public class M_serverApp extends javax.swing.JFrame implements Runnable {
ServerSocket server = null;
[Code]...
In my Java SWT application, I have few methods, that take longer time to complete. These methods has to be initiate and run as response to button click. There I want to implement progress bar to show the progress/status of long run method. Long run methods are Java Processes, in which it executes some command line functionality. (ex: run ls method in Linux).
Process p = Runtime.getRuntime.exec(command)
In progress bar status is set using setSelection method which takes int as argument. How to indicate the progress of process in progress bar, because I don't have int value to pass into setSelection method of progressbar.
i am getting runtime Exception Saying classCastException .here is my code where i am getting classcastException.
public class ModifyDetailsServlet extends HttpServlet {
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
[code]....
why get a runtime error when choosing option 2 after adding a contact?
Main:
package contactlist;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
[code]....
I have a question about updating a grid during runtime in GridWorld. I'm making a game called Flood-It (basically, you click on squares to change their color and attempt to get all of the squares the same color in the grid) and I'm having trouble with changing the grid size. I made my own world class, called CellWorld.
import info.gridworld.actor.*;
import java.util.ArrayList;
import info.gridworld.grid.Location;
import java.awt.Color;
import javax.swing.JOptionPane;
[code]...
Now, let me narrow down the issue. It is in the runner class:
world.setGrid(new BoundedGrid<Actor>(world.getLength(),world.getWidth()));
Whenever a user wants to change the grid size after playing the game, this is supposed to set the grid to the new updated size, but it never changes in the actual game, i.e. the user just won a 2x2 game, attempts to change the size to 10x10, but the grid stays 2x2. By debug testing, I can say for certain that everything else works, such as the maxStepCalc and loading the grid. The only issue is the new grid not showing up.
How can I add computed/derived column to an existing TableModel ?
I've 7 column in the existing TableModel. Now I've to add 8th column and it'll be based on Col2, Col3 & Col5.
Value of Col8 should be in following logic.
public TableModel GetDerivedTable(ResultSet rs){
TableModel model = GetTable(rs); // I've done this
//Now have to modify here
If(Col2==true && Col5==true)
Then{Col8 = 1}
[Code] ....
I am using Swing, I have a JPanel and in it there is a JTextArea and a JButton. I want the JTextArea to move when the button is clicked on. I'm Not really sure how to do the action listener for the button. at the moment the JTextArea only moves once when the button is clicked on, but i want it to move every time the button is clicked on.
This is what i have so far:
moveButton = new JButton("MOVE");
moveButton.setName("move");
moveButton.setBounds(20, 140, 70, 40);
text = new JTextArea("hello");
text.setEditable(false);
text.setBounds(x, 50, 40, 20);
panel.add(moveButton);
panel.add(text);
In the actionPerformed method this is what it does:
text.setBounds(x + 50, 50, 40, 20);
panel.add(text);
text.setVisible(true);
How can i take run time value for static final variable...my lecturer said first time assignment is possible for declared final variable but in my case it shows compile time error..I'm placing my program below with error message
class Sample
{
static final String cname;
void print() {
System.out.println(cname);
}
public static void main(String args[])
{
cname=args[0];
Sample s=new Sample();
s.print();
}
}
Sample.java:11: cannot assign a value to final variable cname.
cname=args[0];