How to run a TestNG class from another class - selenium

Question

Hi When i run the following testNG file as a standalone script if executes as expected.
public class TESTTNGClass {
WebDriver driver;
#Test
public void f() {
System.out.println("In Test");
}
#BeforeMethod
public void beforeMethod() {
System.out.println("Before Test");
}
#AfterMethod
public void afterMethod() {
System.out.println("After Test");
}
}
O/P:
Before Test
In Test
After Test
But why does the same not work when called from another class. Please help to achieve the same when triggered from another class. Following is the class calling the test class
public class TESTClass {
public static void main(String[] args) {
// TODO Auto-generated method stub
TESTTNGClass t = new TESTTNGClass();
t.f();
}
}
O/P:
In Test

Answer 1

Here is the Answer to your Question:
In the process of understanding and experiment with Java & TestNG you have diminished the Annotation power of TestNG.
When you are executing TESTTNGClass.java as a TestNG Test all works well. No issues.
When you are executing TESTClass.java as a Java Application, Java only understands main() where you are creating an object of Class TESTTNGClass and then you are calling the method f(). As Java Compiler have have no idea of BeforeMethod, Test & AfterMethod Annotations of TestNG, it simply executes f() method, prints In Test and ends execution.
About how to do it:
Replace main() by some other name foo().
Bring f() from "TESTTNGClass" class into "TESTClass" class.
While you write "TESTClass" class extend "TESTTNGClass" class.
Execute "TESTClass.java" as a TestNG Test
Your Application will look like:
TESTTNGClass Class:
package Q44240531_TestNG_Main;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
public class TESTTNGClass
{
#BeforeMethod
public void beforeMethod() {
System.out.println("Before Test");
}
#AfterMethod
public void afterMethod() {
System.out.println("After Test");
}
}
TESTClass Class:
package Q44240531_TestNG_Main;
import org.testng.annotations.Test;
public class TESTClass extends TESTTNGClass {
#Test
public void f()
{
System.out.println("In Test");
}
}
Let me know if this Answers your Question.

Answer 2

public class TESTClass extends TESTTNGClass {
public static void main(String[] args) {
// TODO Auto-generated method stub
TESTTNGClass t = new TESTTNGClass();
try{
t.f();
}catch (Exception e){
e.printStackTrace();
}
}
}