命令提示符编译java的方法(必看篇)

package kun;

public class HelloWorld{
  
  public static void main(String[] args)
  {
    System.out.println("hello world");
A a=new A();
a.setValue(120);
System.out.println(a.getValue());
  }

}

class A
{
int value;


public void setValue(int var)
{
value=var;
}

public int getValue()
{
return this.value;
}

public A()
{
value=0;
}

}