Hi, 

To my knowledge, it is always advisable to use @equals (if you are motive is to compare the value of theStrings).

Using == might still work for few strings because when we give a String a "value",  it is not exactly creating an object, it is actually placing it in the String pool, and another same string (say String2) will find the same reference in the pool (Please mind that the String2 is not a new object.)

But in case when you try to use 2 different String instances, then you logic will fail.

Because String instances get evaluated character by character (value evaluation) when @equals is used for comparison.

So, String a = new String("Test1");

String b = new String("Test1");

Would evaluate to true if equals is used (This is the expected behavior).

Would evaluate to false if == is used.

Please note that, if ==  evaluates to true then .equals evaluates to true for sure. 

But, if .equals evaluates to true, there is no guarantee that == evaluates to true. 

Hence, as per my understanding, 

Use equals when you want to compare values of the String and 

== when you want to evaluate the equality on the instance and memory address.

Hope this helps.

Thanks,

Sai