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?
package name;swing library found in javax called to use the graphical contents.
import javax.swing.*;
//creating the contents for the calculator
public class calc {
JButton btn1= new JButton("1 ");
JButton btn2= new JButton("2");
JButton btn3= new JButton("3");
[code]....
I have tried different sizes for the 'TextField' but when I change the size, the position changes instead of the size itself.
I have two string representations of time in "HH:MM:SS" and I want to minus one time from the other.
For example if a = 10:20:30 and b = 00:50:20, i would get 09:30:10. What is the best way to do this?
I would like to be able to change the locale in my Swing application at runtime and have all the text elements on the GUI update themselves with localized text from a ResourceBundle of the new locale.If there a simple way of achieving this without having to create an event model for all GUI pages?
View Replies View RelatedI 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.
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 Replies View RelatedWhile 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.
#
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.
convert or move standalone java thread application into Tomcat server container for accessing its JNDI services? Also is it possible to schedule this thread application in Tomcat server? is it possible to keep this app in tomcat as web application and schedule in window's scheduler.
View Replies View RelatedI 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 have the following classes:
abstract class BaseClass {
}
(doesn't have to be abstract if not necessary, but currently there is no need for it not to be abstract)
class InheritedClassA extends BaseClass {
DataA a;
DataB b;
DataC c;
[Code] ....
Now, I want to get the elements like follows:
BaseClass b = new InheritedClassA();
DataA dataA = b.getDataA(); //returns the DataA field if it's a data member of the inherited class, otherwise null
I know I could do something like this:
abstract class BaseClass {
public DataA getDataA() {
return null;
}
public DataB getDataB() {
return null;
[Code] ...
and override getters as necessary in the inherited classes:
class InheritedClassA extends BaseClass {
DataA a;
DataB b;
DataC c;
public DataA getDataA() {
return a;
[Code] ...
But this introduces an awful lot of boilerplate code, especially in the BaseClass class. In my current plans, there could easily be over a hundred different Data classes, and I would have to write a method that simply returns null for each.
I read about the @Inject annotation and reflection. Is it possible to reduce or eliminate the boilerplate code with these tricks, possibly by putting new methods into the classes?
I'm building a text based "game" where you are communicating with this android creature called Gargoid , at a VERY primitive level . how it works is, simply the user type in a sentence which is decoded for meaning by comparing it with a built in list of words in order to figure out what the user is saying, and then reply with a a relevant response also from a list of built in words. the whole thing would look something like this,
user: what is your name
Gargoid : my name is Gargoid, nice to meet you
user: how is the weather
Gargoid: the weather is wonderful
so far I have 11 arrays which are the following
String[] for user typed in words used for comparison to find meaning ..An Array of String[] , 7 so far, to hold what I call the Gargoid dictionary for example String[] greeting={hi,hello,aloha}, words that indicates greeting int[] called frequency to determine which of the 7 arrays have the greatest "relevancy" to what is being said. and finally another String[] for responses here's the actual code, I want you guys to tell me if there's a way to reduce all this never ending number of arrays? and also is this code a good application of object oriented programming?
MainClass
public class GargoidMain {
public static void main(String[] args) {
TheKeyBoard keyboard=new TheKeyBoard();
TheTranslator translator=new TheTranslator();
TheBrain brain=new TheBrain();
translator.translate(keyboard.userSaysWhat());
brain.respond(translator.userSays());
[code]....
I am working on a project (assignment) and i want to be able to click on jlabel and the select border will show (as shown in the image attached) and i used it to resize the jlabel. I tried
@Override
public void componentResized(ComponentEvent e) {
super.componentResized(e);
setPreferredSize(getSize());
}
});`
yet is not working. I tried some other code that are not working.
A team of programmers is reviewing a proposed API for a new utility class. After some discussion, they realize that they can reduce the number of methods in the API without losing any functionality. If they implement the new design, which two OO principles will they be promoting?
A. Looser coupling
B. Tighter coupling
C. Lower cohesion
D. Higher cohesion
E. Weaker encapsulation
F. Stronger encapsulation
Write a program that reads from the user an integer and reduce it by multiplying its non-zero digits. The result of the multiplication is a number which is to be reduced as the initial one. This process continues until an integer of one single digit is obtained. For example:
64734502 (6 * 4 * 7 * 3 * 4 * 5 * 2) 20160 (2 * 1 * 6) 12 (1 * 2) 2
Your program should display the number obtained in every iteration.
Sample run1
Enter an integer: 64734502
After iteration 1: 20160
After iteration 2: 12
After iteration 3: 2
Sample run2
Enter an integer: 97737999
After iteration 1: 6751269
After iteration 2: 22680
After iteration 3: 192
After iteration 4: 18
After iteration 5: 8
class Father
{
public int a=5;
private int b=10;
[code]...
what is the size of obj from above code?
I am using a 64 bit Win 7 Pc with 64-bit JVM and we get the error: Java heap space. So we want to increase the Java heap size but not for one application but for every application or in general.
We tried with the java -xmx command but it didn't work...
We tried setting the system variable JAVA_OPTS but again it didn't work...
I searched everywhere but i didn't found anything about the real size of primitive boolean type used by java.
View Replies View RelatedI have a major problem. the text size is like 6 or 8 pt font and I can't read it. I'm trying to run a downloaded exe program which uses the jre7 which I had to download beforehand. the font size stays at 6 or 8 even if I try to change it in windows settings. it's a high res monitor on a lenovo yoga laptop. is there a way for me to edit the java code and manually change the font size?
View Replies View RelatedI want to print data on invoice receipt size of 20.5 x 14 cm(hard copy). In which I try to put text at some absolute location. I tried iText first. In that I try to set page size by following code. here what is unite used in bracket of rectangle?
Document document = new Document(new Rectangle(552,377));
PdfWriter.getInstance(document, new FileOutputStream("report.pdf"));
document.open();
...
...
...
document.close();
Second I tried Jasper report. In that I set page size to 20.5 x 14 cm. But how can I take value from my java application's textfield and put it in to some absolute location in iReport.As I know jasper report take value from database but how can I take value from java application's textfiled?
I am more familiar with iText. How can I print custom invoice using iText or Jasper Report.I am developing java application using netbeans.
I have tried running the java application without adding the site to site list in java security tab. But I get a sand box message as APPLICATION BLOCKED BY SECURITY SETTINGS. How to run the java application without adding the site to site list in java security tab.
View Replies View RelatedI've written a java application with several classes all in the same .java file. It works just fine. Now, I've broken it up so that each class has its own .java file. Still works fine. My next step is to put those classes into a package, but I'm not about to get the program to run.The .java source files are all in /home/user/src
I've set the CLASSPATH to /home/user/src..All of the source files have "package com.myfirm.program" on the first line.I compiled the application with:
javac -d . File1.java File2.java File3.java (etc...)
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
java File1
I get: Exception in thread "main" java.lang.NoClassDefFoundError: File1 (wrong name: com/myfirm/program/Program)
I 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]...