I have BlueJ installed on my computer and it does the job of compiling the java source code written in it. If I want to write and compile source code outside of BlueJ do I still need to download the Java SDK and set the PATH variable, even though I am apparently able to do it in BlueJ?
View RepliesCan I add a variable to Windows PATH from java code?
View Replies View RelatedI'm using Ubuntu. After unpacking the tar file for JSE 1.7 version 45, in the the bin directory for adding an entry to PATH variable, I typed
javac
and I get the message
The program 'javac' can be found in the following packages:
* default-jdk
* ecj
* gcj-4.6-jdk
* gcj-4.7-jdk
* openjdk-7-jdk
* openjdk-6-jdk
Try: sudo apt-get install <selected package>
Do I have to install these ?
I am copying the xml files from one folder to other folder, in the source folder, i have some files which have some content like "backing File="$IDP_ ROOT/metadata/iPAU-SP-metadata.xml" but while writing to the destination folder.i am replacing the "$IDP_ROOT" with my current working directory. The entire copying of files is for deploying into tomcat server. The copying is done only when server starts for the first time.Problem: If i change the folder name from my root path in my machine after i run the server,the entire process will be stopped because the destination folder files already contains the content which is with existed files names or folder names.
So i want to change it to relative path instead absolute path. What is the best way to do it? Please look at code below:
[ // Getting the current working directory
String currentdir = new File(".").getAbsoluteFile().getParent() + File.separator;
if(currentdir.indexOf("ControlPanel")!=-1){
rootPath=currentdir.substring(0, currentdir.indexOf("ControlPanel"));
}else{
rootPath=currentdir;
[code]....
I already done my program with images on it but when i convert it to exe , the images is not appearing.
Usually my images are located at documents netbeansprojectprojectimage.jpg
When i run the code on netbeans the images are appearing but when i convert it to exe or jar file run on a computer without netbeans.. images is not appearing ...
import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.ImageIcon;
class Phonebook extends JFrame {
private static final int WIDTH = 430;
private static final int HEIGHT = 200;
public Phonebook()
[Code] ....
I have downloaded jns-1.7 & tried to run an example program "Simulator.java" by specifing the jar classpath while compiling as "javac -cp <path-to-jns-jar-file> Simulator.java". But i got 21 errors as follows:
Simulator.java:3: error: package jns.command does not exist
import jns.command.Command;
^
Simulator.java:4: error: package jns.element does not exist
import jns.element.Element;
[Code] ...
21 errors
I am trying my hand on JNS as i need to deveop a key-distribution scheme (random Key-Distribution scheme) using a simulator. As i have experience in java, i thought to use JNS instead of NS2/NS3 which seems very complex to me.
I'm developing a JavaEE system with several applications on a Weblogic AS (10.3.5) using Eclipse indigo with OEPE plugin. I turned my computer off, turned it back on, started the eclipse, and all of a sudden I get class-path errors all over the place (didn't change a thing).
Now let me get this straight:
1. Say I have an application with one EAR project that contains an EJB project and an EJBClient project (both in the deployment assembly).
2. I have written a new regular Java project, and I want to use it in both the EJB and EJBClient projects (it needs to be visible to them).
3. As far as I know, I can simply add this Java project to the EAR project's deployment assembly, and it will be visible to the EJB and EJBClient projects.
4. This has been working for me so far, but now I get class-path errors and I have to add this Java project to the build path of each project.
How should I set the class-path when using JavaEE technology in Eclipse?
I'm a Java beginner and I've been trying to scan a file using the Java Scanner. I've tried searching online for this error and I only find people's questions who have entered an incorrect relative path. I'm entering in an absolute path and I'm using Eclipse Standard Edition on a 2013 MacBook Pro with Mavericks 10.9.2.
Anyway, the error message I'm receiving on Eclipse is: Exception in thread "main" java.lang.Error: Unresolved compilation problem: Unhandled exception type FileNotFoundException
at App.main(App.java:12)
public class App {
public static void main(String[] args){
String fileName = "/Users/Student/Documents/index.html";
[code]...
Why it cannot find this file. I've checked the absolute file path of index.html on my Mac and I've copied and pasted it into my code.
currently I am doing my java web application project ,and it has following steps 1) Upload the txt files 2) java servlet gets the txt file's url , read the data and do the calculation 3) pass the results
I almost finished the second step , and working on the first step .Since there are so many input files at a given time , i have to use drag and drop method to get the file's location.how to pass file's path to servlet.( servlet code can read the data from the given txt file path )software used - tomcat and netbeans 8.0
In my web application i want to upload file to drop-box. I am getting file name from browser.Is it possible to upload file to drop-box with only file name.
Below the drop-box upload code with java.
File inputFile = new File("New Text Document.txt");
System.out.println("inputFile.getAbsoluteFile(): " + inputFile);
FileInputStream inputStream = new FileInputStream(inputFile);
try {
DbxEntry.File uploadedFile = client.uploadFile("/magnum-opus.txt",
DbxWriteMode.add(), inputFile.length(), inputStream);
System.out.println("Uploaded: " + uploadedFile.toString());
} finally {
inputStream.close();
}
In the above code the place New Text Document.txt we have to provide total path of file.
I have an integer variable called 'selectedname' which is declared as shown below.
public class MainActivity extends Activity implements View.onclickListener, AdapterView.OnItemClickListener {
int selectedname;
So when the app starts an Alert Dialog with two buttons asks the user if they want to tell the first or the last name. The two buttons are 'first' and 'last'.
The problem I'm facing is that in the code the value of selectedname is suppose to change depending on the users choice as shown below.
public void displayWelcome() {
//*other code comes here but it works fine*
AlertDialog.Builder choice = new AlertDialog.Builder(this);
choice.setTitle("Yo!");
choice.setMessage("First name or last");
choice.setPositiveButton("First", new DialogInterface.onclickListener() {
public void onclick(DialogInterface dialog, int whichButton) {
selectedname = 1;
[Code] .....
Is there a way to have global variable in Java associated to a process ?
I'm coming from PL/SQL world, I'm looking for something like package variables.
Given the case I have an object which is assigned only once. What is the difference in doing:
public class MyClass {
private MyObj obj = new MyObj("Hello world");
private MyClass(){}
//...
}
and
public class MyClass {
private MyObj obj;
private MyClass(){
obj = new MyObj("Hello world");
}
//...
}
Is there a difference in performance or usability? (Given also the case there are no static calls expected) ....
The term "Local variable" is related to scope. That is a local variable is one which is defined in a certain block of code, and its scope is confined inside that block of code.And a "Member variable" is simple an instance variable.
I read in a discussion forum that when local variables are declared (example code below), their name reservation takes place in memory but they are not automatically initialized to anything. On the other hand, when member variables are declared, they are automatically initialized to null by default.
Java Code: public void myFunction () {
int [] myInt; // A local, member variable (because "static" keyword is not there) declared
} mh_sh_highlight_all('java');
So it seems that they are comparing local variables and member variables. While I think a member variable can also be be local in a block of code, isn't it?
Suppose I have a class child
public class child{
public static int age = 1;
}
And I am using class child static variable age in class school
public class school{
int var_age;
public school(){ //school constructor
var_age = child.age;
}
}
Value in age of child class could be any of these below depending on some logic:
public static int age = 1;
public static int age = 2;
How could i achieve this where should i apply that logic? Also it is mandatory for class school code to remain same.
I want to access variable of java file into jsp Page. So I tried to do this but it does not work.
Problem : when I am trying to access "getName" method of java class into jsp file it displaying error, i already imported "Ajaxmethod.java" file in to "success.jsp" I want to access "getName" method in to jsp file without creating object of class.
Ajaxmethod.java
package a.b;
public class Ajaxmethod implements Action{
public String name;
public String getName() {
return name;
}
[Code]...
Right so I have my ItemsPage Jframe Class and I'm trying to pass my TotalPrice variable to my CashPay so I can calculate the change. CashPrice runs and works but when I try run ItemsPage it does nothing I don't even get errors. I tried to remove that small section of trying to pass the variable to CashPay and it worked perfectly so I 100% know that's the problem. This section "public ItemsPage() { Pounds = ""; //super();
Scanner sc = new Scanner(System.in);
CashPay sendTotalPrice = new CashPay();
//System.out.println("Enter your amount");
TotalPrice = sc.nextDouble();
sendTotalPrice.printTotalPrice(TotalPrice);
"
Here is complete code for both classes, I'm using GUI builder.
import java.awt.BorderLayout;
import java.awt.Checkbox;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
[code].....
My dynamic web project has a java class that captures a session variable with the following code.
HttpSession LoginSession = request.getSession();
String VAR = LoginSession.getAttribute("myVar").toString(); //This is the row 127
If i test the app in local (Mac + Java 1.8 + Tomcat 8) all works. In my remote cloud server (Ubuntu 14.10 + Java 1.8 + Tomcat 8) all works, except this class, that has this code. I copy the complete error here. Note that the row 127 of the error message is the second row of the previous code; and, if i comment this row with // and assign a fix variable all works. So, the problem is that 127^ row.
14-Dec-2014 08:15:23.923 SEVERE [http-nio-8080-exec-14] org.apache.catalina.core.StandardWrapperValve.invoke Servlet.service() for servlet [srvNavigation.SrvPT] in context with path [/myapp] threw exception
java.lang.NullPointerException
at srvNavigation.SrvPT.doGet(SrvPT.java:127)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
[Code] ....
How can i solve the problem?
Can I store multiple rows of a table in a two dimensional string array in java.. The table has 3 columns and approximately 10,000 rows.. Some pointers for coding to achieve this...
View Replies View RelatedI am working on some enhancement on application. I have a requirement. The flow is as below
In a jsp file one selection dropdown exists and a body. Selection dropdown is written as custom tag library and is included in jsp file eg tag.tld whose code exists in tag.java code for other parts of jsp are written in that *.jsp file itself. eg test.jsp
i.e test.jsp calls tag.tld to include selection dropdown
I now want a hashmap created in tag.java to be available in jsp file and I want to use it in one of the javascript function available in same jsp file for validation
How can I achieve this....
Is there a method in Java API that truncate the float part of a double variable after a given number of digits?
Example: if the number of digits to be truncated is 2, so the method truncate (6.9872) to (6.98) ,
I tried to write a method that do that but it was very difficult.
Given a reference variable : Car c1 = new Car();
when we create another variable and set it equal to the first : Car c2 = c1;
we're pointing c2 at the same car object that c1 points to (as opposed to pointing c2 at c1, which in turn points at the car). So if we have code like,
Car c1 = new Car();
Car[] cA = {c1, c1, c1, c1};
are we doing the same? Are we creating four *new* reference variables, each of which points at the same car (again as opposed to pointing them at c1 itself)? I think so, but want to make sure I'm understanding this correctly.
I am trying to write a program and the name variable can only store letters,dotes and spaces. But whenever I enter a space, the program doesn't work. Following is my code.
import java.util.Scanner;
import java.util.*;
public class Space {
public static void main(String []args) {
Scanner reader = new Scanner(System.in);
[Code] ....
I have a JFrame jf and JPanel jp on it. jp has five TextFields named cel1, cel2.. cel5. I wish to construct a String Cel + for loop index and run a for loop to reset the values of all the text fields using a single statement such as cel1.SetText("abc"). Similar things can be done in foxfro. How does one do it in java?
View Replies View RelatedMy OS: Windows 7
Problem:
I've tried where javac in command prompt but it can't locate it. I need to know how to set JDK 8 as PATH.
What I do wrong when I trying to set path to file in my jar app. I have application which work with xml file. I have next project structure:
/project_root_directory
|_ /lib
|_ /resources/file.xml
|_ /src
So, I need to set correctly path to my jar file, because when I running it from IDE, it works nice. By default it seems:
private File file;
private StreamResult streamResult;
file = new File("resources/file.xml");
streamResult = new StreamResult(file);
And methods where I can modify the DOM structure via transformer in end of methods:
transformer.transform(source, streamResult);
So, I trying set path to file:
private URL url;
...
file = new File(url.getPath());
streamResult = new StreamResult(file);
But it didn't not work, because when I trying to get resource by next condition
url = getClass().getResource("resources/file.xml");
url = getClass().getResource("resources/file.xml");url = getClass().getResource(url = getClass().getResource("resources/file.xml");resources/file.xml");
url - is null
Okay..
I tried next solution
InputStream input = getClass().getResourceAsStream("resources/file.xml");
There, I got also null....
Also, I tried made absolute path
filePath = file.getAbsolutePath();
file = new File(filePath);
streamResult = new StreamResult(file);
But it also didn't work. There I got message seems like: "Can't find resource /User/user1/Desktop/program1/resources/file.xml" - but that's really absolute path to a file.
Also, I tried made it via System.getProperty
String filename = "file.xml";
String workingDir = System.getProperty("user.dir");
finalfile = workingDir + File.separator + "resources" + File.separator + filename;
file = new File(finalfile);
I also made unit test which completed with "green light", but in jar its wrong with message "Can't find resource /User/user1/Desktop/program1/resources/file.xm" ....