public class Solution2 {
    public static void main(String[] args) throws Exception
    {
        method1();
    }

    public static String method1()
    {
        method2();
        // код
        return ...;
    }

    public static String method2()
    {
        StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();
        for(StackTraceElement element : stackTraceElements) {
            return element.getMethodName();       // не верно
        }
        return null;
    }
}

public class Solution2 {
    public static void main(String[] args) throws Exception
    {
        method1();
    }

    public static void method1()
    {
        method2();
        StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();
        System.out.println("из метода 1: "+stackTraceElements[2].getMethodName());
        //return null;
    }

    public static void method2()
    {
        StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();
        System.out.println("из метода 2: "+stackTraceElements[2].getMethodName());  // вызвавший
        //return null;
    }
}

public static void main(String[] args) throws Exception
    {
        method1();
    }

    public static int method1()
    {
        method2();
        StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();
        int ln=stackTraceElements[2].getLineNumber();
        //System.out.println(ln);
        return ln;
    }