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when I execute it shws main method not found in class avarage,please define your method [duplicate]

This question already has answers here:
"Error: Main method not found in class MyClass, please define the main method as..."
(10 answers)
Error: Main method not found in class Calculate, please define the main method as: public static void main(String[] args) [duplicate]
(5 answers)
legal main method signature in java
(8 answers)
Closed 2 years ago.
public class avarage
{
public void main(int subjectmarks)
{
System.out.println("Eneterd subject marks:"+subjectmarks);
}
}

The compiler shows the above error because it cannot find the native main function signature. Just declare the integer subjectmarks inside the main function and do not pass it as arguments in the main function, like below for example:
public class avarage {
public static void main(String[] args) {
int subjectmarks = <some-value>;
System.out.println("Eneterd subject marks:"+subjectmarks);
}
}

java static method why is needed [duplicate]

This question already has answers here:
"Non-static method cannot be referenced from a static context" error
(4 answers)
Closed 6 years ago.
I'm using eclipse as IDE for java.
I wrote the following code, but I have one error on loadStrade(). Eclipse suggested me to change loadStrade from public void to public static, and I don't understand why?
I've looked for similar problem and I've found some problems like mine, but I still not understand why I have to change method to static. Uffa!
In the code, routesNet is a graph (jgraphT), and loadStrade() is used to populate vertex and edge.
Can I have help. Thanks, Fabrizio
public class GestioneStrade {
private Stradario routesNet;
public static void main(String[] args) {
/*
* Instantiate Stradario and fill it with routes and cross
*
*/
GestioneStrade m = new GestioneStrade(); //istance of gestionestrade ok?
// now I set new routesNet
m.setRoutesNet(new Stradario());
loadStrade(m.getRoutesNet()); // why loadStrade must be static :-(
}
public Stradario getRoutesNet() {
return routesNet;
}
public void setRoutesNet(Stradario routesNet) {
this.routesNet = routesNet;
}
public void loadStrade(Stradario str) {
// some code to fill routesNet
}

In "main" you should replace
loadStrade(m.getRoutesNet());
to
m.loadStrade(m.getRoutesNet());
And leave loadStrade as non-static.

Static method getting called using a null reference [duplicate]

This question already has answers here:
Why I am not getting NullPointerException? [duplicate]
(6 answers)
Closed 6 years ago.
public class Test {
public static void main(String[] args) {
Test test = null;
test.func();
}
static void func(){
System.out.println("Hello!!");
}
}
Why this program is getting executed successfully?

This is because static methods are not related to instances. Compiler internally convert this and call Test.func()

You call a static method. Static methods are invoked on Classes.
The call is like this Test.func().
Tip: In your code when you call static methods. Call them Class.method() not on object.

In a constructor, find which class created the object? [duplicate]

This question already has answers here:
How do I find the caller of a method using stacktrace or reflection?
(13 answers)
Closed 8 years ago.
Here's what I'm trying to do:
In my code, I have sets of classes that create objects of other classes. What I am trying to do is, in the constructor of the class that's constructor gets called, find the class which called the constructor in the first place.
For example:
Main.java:
public class Main {
public static void main(String[] args) {
Test t = new Test();
}
}
Test.java:
public class Test {
public Test(){
//somehow find the class where I came from :(
}
}

Assuming that you can't pass in the Class object of your caller: Other than the fact that the very need for this implies a rather obnoxious design, then, the only way you can do this is to construct an exception and inspecting the last stack trace element in it:
Exception e = new Exception();
StackTraceElement[] elements = e.getStackTrace();
The first element in the array is what you're looking for.
(Updated following a comment) This won't work consistently in JITted environments.

You can use something like this:
public class Main {
public static void main(String[] args) {
new Main().runMe();
}
public void runMe() {
new Test(this.getClass());
}
}
class Test {
public Test(Class clazz) {
System.out.println("I was invoked from '" + clazz.getCanonicalName() + "' class.");
}
}
Prints:
I was invoked from 'Main' class.

Exception in thread "main" java.lang.NoSuchMethodError: main [duplicate]

This question already has answers here:
"Error: Main method not found in class MyClass, please define the main method as..."
(10 answers)
Closed 9 years ago.
when i try to compile this:
public class Risk
{
}
class territory
{
public static void main (String[]arg)
{
System.out.println ("hi") ;
}
}
I get this error message:
Exception in thread "main" java.lang.NoSuchMethodError: main
whats going wrong here?

The class containing the main() function must be public, and you may only define one public class per file. You'll want to have two separate files Risk.java and Territory.java.
Risk.java:
public class Risk {
}
Territory.java:
public class Territory
{
public static void main (String[]arg)
{
System.out.println ("hi") ;
}
}
EDIT: It turns out this isn't true - I was able to run your initial code with the following command line:
java territory
But my earlier comments point to the best practice for a real app, such as a Risk game.

What class are you trying to run? If you're using the class territory, that will work. Risk has no main method, though.

Can you figure out why this example causes the same issue?
public class Simple {
public void main(String args[]) {
System.out.println("Inside function");
}
}
Answer: because main() should be public static void!

Could it just be a spacing issue? Your original post shows no space between the ']' and 'arg'.
Try this:
public static void main (String[] arg)
or, if that still doesn't work:
public static void main (String arg[])

What the answer wound up being was that the class i run must contain main or else it won't work. i'm posting this because, though other answers give roughly the same information, they don't make it explicit.