Can A Class Be Defined Inside Interface
Feb 15, 2014Can a class be defined inside an Interface .
interface Inter{
class x{
public static void main(String[] args){
System.out.println("Hello World!");
}
}
}
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Swing/AWT/SWT :: Non-final Variable Inside Inner Class Defined In Different Method
Aug 9, 2014this code won't compile because selected row must be declared as final because of it being defined outside the window listener. Is their anyway around this? If I make it final the first time that the variable is called it keeps it starting value until the GUI is closed.
butEdit.addActionListener (new ActionListener () {
@Override
public void actionPerformed (java.awt.event.ActionEvent evt) {
int selectedRow = table.getSelectedRow ();
final String [] values = custTableModel.getRowValues (selectedRow);
[code]....
Cannot Refer To Non-final Variable Inside Inner Class Defined In Different Method
Apr 3, 2014Created a java.sql.connection object. Refering those obj inside public void run() { } If i declare as final inside a method, i can't refer those outside method due to scope. Cannot refer to a non-final variable dbConnObj inside an inner class defined in a different method...
View Replies View RelatedCreating Class Inside A Interface
Jun 22, 2014I am not able to understand how we are able to create an object of static inner class defined inside an interface .
interface outer {
class inner {
void disp() {
System.out.println("inside disp");
[Code] ....
output:
inside disp
How am i able to create a new object for static class?
Can Declare A Class Inside Interface?
May 8, 2013I have a doubt regarding to java.
Can we declare a class inside an interface?
Ans :yes
But what will be the situation?
I am not getting why it is required...........
Interface Inside Abstract Class
Jul 8, 2015What this interface inside that abstract class does. Looking for some examples to how can i use it ....
public abstract class Expression {
public abstract String toString();
public abstract SimpleExpression evaluate();
public void show() {
System.out.println(this + " = " + evaluate());
[Code] ....
Access Getter / Setter Of Bean Class Where It Defined As Member In Another Class?
Feb 18, 2014Class UserAssessBean{
private String username;
private int userid;
private ArrayList<ModuleBean> module;
--{get/set}--
[Code] ....
How can i access the getters/setters of module bean, when it was returned as array list in UserAssessBean?
Class Defined Under Another Class - Sorting Elements In Reverse Order
Jul 4, 2014I have never seen a class defined under another class ....
class pe{
static class pqsort implements Comparator<integer>
public into compare(Integer one,Integer two)
return two-one;
}
}
First I want to know how class pqsort is defined under class pe ....
And how the comparator used in this example is sorting elements in reverse order
Extending Static Inner Class Defined Within Inheriting Class?
Jul 3, 2014I am working on a project involving a class that has the attributes of one of its inner classes. Now, if possible, I would like to make it so that the inner class is not visible outside of the class. Also, some of the functional mechanics require that the class be an instance of the nested inner class (it extends the inner class). The following code snippet demonstrates the situation.
public class A extends A.B {
public static class B { //ideally I would like this to be private/protected.
}
}
When I try to compile this program, I get the error message "Cyclical inheritance involving A." This error does not make much sense because, since the inner class "B" is static, it requires no instance of "A" (it does not inherit from "A" or uses it). My question is "Is it possible to do something similar to this structure?" I have searched many forums in search of the answer but have not found anything that attempts to explain it. The closest problem that I have found is one relating to the inheritance of a nested inner class from another class. I would like to express that the problem that I am having involves a class defined within the inheriting class.
Implement Method Inside Interface
Sep 3, 2014if i call a class that implements an interface the method inside the interface will be triggered automatically by the compiler or happens only in the observer pattern? i keep simple to be surr the message came across, a typical example would be a listener on a button, or a collection that calls comparator)
View Replies View RelatedWhat Happens To A Static Variable That Is Defined Within A Method Of A Class
Feb 15, 2014What happens to a static variable that is defined within a method of a class ?
View Replies View RelatedInterface Class And Object Class Is Compiling Symbol Errors
Nov 16, 2014I am a beginner here at JAVA and I am trying to program a Gratuity Calculator using both interface class and object class but it keeps on compiling with errors saying "cannot find symbol".I tried everything to fix it but it just keeps on stating symbol.
[CODE]
public class GratuityCalculator extends JFrame
{
/* declarations */
// color objects
Color black = new Color(0, 0, 0);
Color white = new Color(255, 255, 255);
Color light_gray = new Color(192, 192, 192);
[code]....
How To Create Object For Multiple Class Inside Single Class
Apr 22, 2015How to create object for "class B" and call the "function_B" from other different class D where class D has no connection with class A? Here is my program.
public class A(){
void print(){}
}
class B{
void function_B(){}
}
class C{
void function_C(){}
}
Here, A, B, C are in the same package. But class D is in different package.
Structs In Java - Can Put Class Inside A Class?
Mar 17, 2014I will give an example below of what I am talking about. in C++ I know I would need a copy constructor because I would be pointing blindly in the heap if I deleted a object in the struct.
We have a Class/struct animal and three animals in that class/struct, a dog, a cat and a cow. Each animal has a baby and then I will give the animal a name in main. But if I delete one of the dogs puppies because I sold him wouldn't I being pointing off in the heap and have a leak?
Also since Java doesn't have structs can I put a class inside a class?
When To Use Interface And Abstract Class
Apr 17, 2014I know whats the interfaces and abstract class and also know that difference between interface and abstract class,but here my doubt is eventhough abstract class more advantage than the interface,then why should we use interfaces and when?
View Replies View RelatedCan Interface Extend A Class
May 16, 2014Can an interface extend a class?When I am running the following code it's showing some errors..I have commented them.
class A {
public void methodA() {
System.out.println("Class A methodA");
}
}
interface B extends A //interface expected here {
public void methodA();
[code]....
When A Class Or Interface Will Be Initialized
Sep 18, 2014class Super { static String ID = "QBANK"; }
class Sub extends Super{
static { System.out.print("In Sub"); }
} public class Test{
public static void main(String[] args){
System.out.println(Sub.ID);
}
}
According to me output should be "QBANK" In Sub...BECAUSE sub default constructor will call super() constructor.. below is the definition in jls which i am unable to understand ....
A class or interface type T will be initialized at its first active use, which occurs if:
T is a class and a method actually declared in T (rather than inherited from a superclass) is invoked.
T is a class and a constructor for class T is invoked, or T1 is an array with element type T, and an array of type T1 is created.
A non-constant field declared in T (rather than inherited from a superclass or superinterface) is used or assigned. A constant field is one that is (explicitly or implicitly) both final and static, and that is initialized with the value of a compile-time constant expression . Java specifies that a reference to a constant field must be resolved at compile time to a copy of the compile-time constant value, so uses of such a field are never active uses.
All other uses of a type are passive. A reference to a field is an active use of only the class or interface that actually declares it, even though it might be referred to through the name of a subclass, a subinterface, or a class that implements an interface.
Anonymous Inner Class For Interface
Jul 29, 2014I am new to java coding.... When we create anonymous inner class for interface, we get one object for the sublcass of that interface .
In interface there is no constructor then how do we get that object. We know that to create Anonymous inner class we should use one super class constructor.
Whether my understand is correct or not.
Difference Between Abstract Class And Interface?
May 18, 2011Difference between Abstract class and Interface??
View Replies View RelatedHow To Implement Interface And Extend Class
Apr 12, 2014how to 'implement' an interface and 'extend' a class. Now I want to try and recall the information by memory without using any reference material.
Implementing an interface...
Java Code: //This interface will hold information for cell phones//Like saying... you can't BE a cell phone unless you have this information, at the very least
public interface CellInfo {
public void model();
public void make();
public void androidVer();
}
//Now I implement the interface for a class called Galaxy, which is a class about a specific phone
public class Galaxy implements CellInfo
public void model() {
System.out.println("I'm a Galaxy S5.");
}
public void make() {
System.out.println("I'm made by Samsung.");
[code]....
Reason To Create Inner Class In Interface
Mar 3, 2012interface Interface{
class B{
}
}
I know that we can create an inner class inside an interface but i want to know that why we'll create an inner class inside an interface. I mean what is the use of creating inner class inside an interface and what is the advantage of it.
List Interface Class That Has Operations For Linked List And LList Class
Oct 6, 2014I have this ListInterface class that has operations for my linked list and a LList class. The Llist and ListInterface classes are perfect. My job is to create a driver, or a demo class that showcases these operations. That being said, heres the driver so far:
import java.util.*;
public abstract class DriverWilson implements ListInterface
{
public static void main(String[] args)
{
LList a = new LList();
[code]....
Getting Error - Class Interface Or Enum Expected
Aug 7, 2014import java.io.*;
class addition {
public static void main(String[] args) {
int num1,num2,sum;
try {
DataInputStream x=new DatainputStream(system.in);
[Code] ,,,,,
Create And Simulate ATM Interface Using Scanner Class
Sep 28, 2014 I need to create and simulate an ATM interface for my computer programming class using scanner class, if else & switch statements. I've been working on this assignment all day and I'm still no closer to figuring out how to do it. I'm currently working in NetBeans to try and solve it. I have attached the pdf , what I need to do. This is what I have so far:
package bankatmifelse;
//Gator Bank ATM Program
import java.util.Scanner;
public class BankATMIfElse {
[code]...
Java Interface - Implement Method In Another Class
Sep 17, 2014So I created an interface which has the method
int getCalls();
I am trying to implement this method in another class but I'm not sure how to do so. My attempt is:
public getCalls(){ return getCalls(); }
When I run the program it sends the following exception:
Exception in thread "main" java.lang.StackOverflowError
at FibonacciForget.getCalls(FibonacciForget.java:14)
and it highlights the [return getCalls();] part.
What is the correct way to implement the getCalls() method?
Widget Class That Implement Comparable Interface
Mar 15, 2014Below is the requirements and code. I am getting the error CODELAB ANALYSIS: LOGICAL ERROR(S)We think you might want to consider using: >
Hints:
-Correct solutions that use equals almost certainly also uses high
-Correct solutions that use equals almost certainly also uses low
Assume the existence of a Widget class that implements the Comparable interface and thus has a compareTo method that accepts an Object parameter and returns an int . Write an efficient static method , getWidgetMatch, that has two parameters . The first parameter is a reference to a Widget object . The second parameter is a potentially very large array of Widget objects that has been sorted in ascending order based on the Widget compareTo method . The getWidgetMatch searches for an element in the array that matches the first parameter on the basis of the equals method and returns true if found and false otherwise.
public static boolean getWidgetMatch(Widget a, Widget[] b){
int bot=0;
int top=b.length-1;
int x = 0;
int y=0;
while (bot >= top)
[code]....