I am unsure of something. In the following class, which is read first; the static field or the main method?
class Test{
static int a = 3;
public static void main(String args []) {
//some code}
}
I put some code in Eclipse and have tried to look at the hierarchy. It would point to all static fields being initialized in order from top to bottom, including the main method.I had thought that the main method was always the first thing in a public class to be initialized, regardless of where in the code it resides. Am I reading the Eclipse hierarchy wrong? I find Eclipse very difficult, especially since I typically code in Textmate. I just want to see how my code is operated upon,
If I define a class which contains a few static fields, and then have a few classes who inherit this class, then all these classes would have the static field as well. Now my question is the following: would all those sub classes (and the base class itself) share the same object, or would each class have one object for all it's instances?
I have a program which consist of several classes. The program reads a pom file and parses the data and then writes the data to a static table. The issue I'm having is with writing my LIB file data to my table. In the HtmlDataTable Class Im trying to write the files that are read in the lib directory to the table. My table currently consist of 3 columns (missing jar files,Lib Directory files, and POM file data) currently Im only able to write the missing jar files data to my table. In the HtmlDataTable class there is a for statement where I write the missing jar file data to my table. Im also trying to write the contents of the Lib directory within this statement as well. This is where I'm having my issue. My other classes consist of a SAX parser which parses the xml file, a class that creates my static table and a class that compares the jar files in my lib directory to the jar files in my pom file. . Theres a lot of code so I included the parts I felt were useful. If needed I can include the other classes as well.
public class ReadPomFile extends DefaultHandler { public static void main(String[] args) { try { // obtain a SAX based parser to parse XML document
how to differ between fields that are not exists to fields that are null? because in my api when someone wants to delete a field he sends null instead of a value. and if he doesnt want to effect this feild he doesnt send it.
One of the random number generators in Java extract the higher-order bits of the random number in order to get a longer period.
I'm not sure if I understand how this is done. Suppose that the random number r = 0000 1100 1000 1101. If we extract the 16 most significant bits from r; is the new number r = 0000 1100 or r = 0000 1100 0000 0000?
I use this code in Restlet Representation. I try to get the value from the Request API. But I am facing the problem as "Cannot make a static reference to the non-static method getQuery() from the type Resource".
From what i understand static methods should be called without creating an instance of the same class . If so why would they return an instance of the same class like in the following : public static Location locateLargest(double[][] a) , the Location class being the same class where the method is defined . I don't understand this , does it mean that every field and every method in the class must be static ? Meaning that you cannot have instances of the class because everything is static . Or it's just a mistake and the class Location cannot have a static method: public static Location locateLargest(double[][] a) ?
I can't figure out what this error message "Cannot make a static reference to the non-static method getEndUserCharge(long, long, long, long) from the type UpdateUserWS" actually means.
The error is coming from:
public void updateDetailsPackage() { some unrelated code long zero=0; double endUserCharge=0; endUserCharge = UpdateUserWS.getEndUserCharge(long zero, long zero, long zero, long zero); <-------- error is here
I am trying to call an actionListener which is shown below in my PSVM :
class testMenuItemListener implements ActionListener { public void actionPerformed(ActionEvent arg0) { getContentPane().removeAll(); createPanel(); getContentPane().add(panel1); //Adding to content pane, not to Frame repaint(); printAll(getGraphics()); //Extort print all content
[Code] .....
I get the following error :
Frame.java:409: error: non-static variable this cannot be referenced from a static context menuItem1.addActionListener(new testMenuItemListener());
I am trying to add a field (called special) to a hibernate table. I am copying existing code (related to the NAME field) so I don't have to figure this out from scratch. I am getting the error
"[ERROR] C:VOXvoxware-1.1.13voxwarevoxware-implsrcmainjavacomvoxwareimplflowVoxFlowConfiguration.java:[213,38] error: non-static variable special cannot be referenced from a static context".
Line 213 is in public void mergeFrom, the actual line is "special = VoxFlowConfiguration.special;" I don't understand why Java thinks special is a "non-static" variable but it doesn't have a problem with the other variables (such as name, orderShow)
I'm working on a banking program that is supposed to use 3 classes (Account-base class, CheckingAccount, and SavingsAccount) and several methods to display the banking information (ID, balance after a withdrawal and deposit, and the annual interest rate). This should be a pretty simple program, but I'm getting hung up on one portion of it. I'm getting some compiler errors, all of which deal with non-static variables being called from a static context (I'll also post these errors following the code). Up until the middle of last week, we just declared everything as static, but that's changed and I'm having trouble figuring out when to and when not to use static when declaring my methods, hence the compiler errors.
import java.util.Date; public class Account { private int id = 0; private double balance = 0; private double annualInterestRate = 0; private Date dateCreated = new Date();
[Code] ....
Here are the compiler errors I am receiving:
Compilation completed. The following files were not compiled: 6 errors found: File: C:UsersHiTechRedneckDesktopSummer II 2014Computer Programming PrincipleProgram 5CheckingAccount.java [line: 7] Error: non-static method getId() cannot be referenced from a static context
I am trying to call an actionListener which is shown below in my PSVM :
class testMenuItemListener implements ActionListener { public void actionPerformed(ActionEvent arg0) { getContentPane().removeAll(); createPanel(); getContentPane().add(panel1); //Adding to content pane, not to Frame repaint();
[Code] .....
I get the following error :
Frame.java:409: error: non-static variable this cannot be referenced from a static context menuItem1.addActionListener(new testMenuItemListener());
I am writing the following program in Java SE 7. It throwing "Cannot make a static reference to the non-static type String" . However if I write parameterised String inside main method as java.lang.String[] args, it compiles fine.
class MainClass<String> { <T> MainClass(T t) { System.out.println(t.getClass().getName()); } public static void main(String[] args) { System.out.println("asdasd"); new MainClass<>(""); } }
I mean following programs compile fine in Java SE 7 :
class MainClass<String> { <T> MainClass(T t) { System.out.println(t.getClass().getName()); } public static void main(java.lang.String[] args) { System.out.println("asdasd"); new MainClass<>(""); } }
If i try to make it public void than it say can't call non-static methods inside static(main).if i try to put it into new class and then call it after i fail input it goes into infinite loop.
The error said : Non Static Variable TAShaReport Cannot referenced from a static context
I just want to put the output in the TextArea
Here is the code :
public static String DeduplicateFiles(String myFolderLocation) { try { HashSet<String> newset = new HashSet<>(); File folder = new File(myFolderLocation); //Directory where the files are located File[] listOfFiles = folder.listFiles();
I had a TestColor class which contained methods to change hue, saturation, brightness, red, green, blue of TestColor's instances but also had static methods which take in an additional parameter for an instance of TestColor and returns the affected instance of TestColor. Now instead of having one method for every possible color effect to be applied to an image, how can I have one method that takes in an Image parameter, a static or non-static method reference from TestColor parameter and lastly an intensnity value parameter. This is so that I can make an affectedImage object instance inside the method and a Graphics2D object for drawing to each pixel of the new image, now I have one for loop and one nested for loop for the x and y pixels of width and height of the old image and inside the nested for loop I'd create a TestColor by calling getRGB on the image's pixel. Then I would apply the static or non-static method reference somehow to change the color with the intensnity value and after applying it draw to the new Image with Graphics2D. How to would I parametize a method reference and be able to use it in such way?
This is a someway special question, because I am using jmonkeyEngine.
But the topic is simple:
I have 2 classes:
public class Spielbrett extends SimpleApplication { public static void main(String[] args) { Spielbrett app = new Spielbrett(); app.start(); } @Override public void simpleInitApp() {
[Code]...
as the main class and a second class for the chips:
public class Spielstein { public Spatial stone; public int player; public int team; private AssetManager assetManager = Spielstein.getAM(); //THIS IS THE PROBLEM public Spielstein(int t_player, int t_team){
[Code]...
My problem is: I can't access getAM() from the first in the second class. If you know why I would be glad for an answer.
One of my friend asked me that which will load first static variable or static block ? My answer was to static variable.. So he gave me two program and said to differentiate between them
1st program
public class Test { public static void main(String args[]) { System.out.println(Test.x); } static { System.out.println(Test.x);
[Code] ....
Output of this :
90 90
I tried to decompile the byte code and found it's same for both the above equation. How to differentiate between them. I am confused when the static variable will initialised.
One class having two method one as static n another as non-static, 2 threads are there t1 is accessing the static method and t2 the non-static method is it possible n both are sharing the same object.
I now we have two kinds of lock one is object level lock and another is class level lock
package Experimentation; import javax.swing.*; import java.awt.event.*; public class SimpleGUI1B implements ActionListener { JButton button; public static void main(String[] args) { SimpleGUI1B gui = new SimpleGUI1B(); gui.go();
[code]...
This is a program from Head First Java! since main is static it shouldn't be able to call non-static methods because statics do not use any instance variable values but in the above program we're call a non-static method go() how is it possible?
I am trying to compile the following code where the entry point is Main.java but i am getting the following error "Error non-static method add(int[]) cannot be referenced from a static context in Java " ....
If i add the keyword static in add method of A.java it works properly......
Class Main.java code package com.company; public class Main { public int [] a= new int[]{1,2,3}; public static void main(String[] args) { Main n= new Main();
I’m trying to understand how to decide when to make a nested class static or non-static. These are my assumptions.
1) Make a nested class static if each instance of its enclosing class may have one or more instances of its nested class, for example, a HashMap has a static HashMap.Entry nested class because each HashMap instance may have one or more HashMap.Entry instances
2) Make a nested class non-static if each instance of its enclosing class must have only one instance of its nested class, for example, an AbstractButton has a non-static AbstractButton.Handler nested class because each AbstractButton instance must have only one AbstractButton.Handler instance.
