Hi, I would like to tell you about my preparation for the exam 1Z0-899:
1 - I read Head First Servlets & JSP;
2 - I read the specs of Servlets, JSP and JSTL;
3 - I read OCEJWCD Study Companion of Charles Lyons. In the mock exam in the final of the book I got 71%.
4 - I resolved the questions of the book Java Practice Questions with an average grade of 54%;
5 - I resolved the questions of Enthuware mock exams with the following grades: 57%, 71%, 78%, 75%, 79%, 79%, 82%, 86%, 86% and 77%.
Finally, in 2018-12-19 I took the real exam and passed with 94%.