Error: Could not find or load main class com.example.Test

I was searching for how to access the private field of a class from other class and found that it can be done using reflect.Field as in the following code, but when i try to execute the code i get an error saying :Error: Could not find or load main class com.example.Test

why is it happening?

Test.java

package com.example;

import java.lang.reflect.*;

class Test
{
    public static void main(String[] args)
        // Just for the ease of a throwaway test. Don't
        // do this normally!
        throws Exception
    {
        Other t = new Other();
        t.setStr("hi");
        Field field = Other.class.getDeclaredField("str");
        field.setAccessible(true);
        Object value = field.get(t);
        System.out.println(value);
    }
}

Other.java

package com.example;

class Other
{
    private String str;
    public void setStr(String value)
    {
        str = value;
    }
}