java - how does jvm enter in public static void main?

Question

How can jvm enter in default class:

class try1
{
public static void main(String args[])
{
    ...
}
}

In it how does JVM access this method?

In packages, if a class is 'default' its public methods cant be accessed from outside the package, so how does jvm enter this class?

Answer 1

It is not JVM itself who invokes main method. This is rather a job of Java launcher, i.e. java.exe.
Java launcher is a small program written in C that uses regular JNI functions:

1. JNI_CreateJavaVM to create a new instance of JVM and to obtain an instance of JNIEnv;
2. JNIEnv::FindClass to locate the main class specified in the command line;
3. JNIEnv::GetStaticMethodID to find public static void main(String[]) method in class #2.
4. JNIEnv::CallStaticVoidMethod to invoke the method found in #3.

In fact, JNI allows you to work with all classes, methods and fields, even with private modifier.