adding Java section in Arabic books and 2 java books (#7450)

* adding Java section in Arabic books and 2 java books

* adding Java section in Arabic books and 2 java books, fixing alphabetize-lists

books/free-programming-books-ar.md

@@ -8,6 +8,7 @@
 * [DB & DBMS](#db--dbms)
 * [HTML and CSS](#html-and-css)
 * [Introduction to Programming in Arabic](#introduction-to-programming-in-arabic)
+* [Java](#java)
 * [JavaScript](#javascript)
     * [Vue.js](#vuejs)
 * [Linux](#linux)
@@ -58,6 +59,12 @@
 * [مختصر دليل لغات البرمجة](https://alyassen.github.io/Brief-guide-to-programming-languages-v1.2.4.pdf) - Ali Al-Yassen‏ (PDF)
 
 
+### Java
+
+* [تفهيم الخوارزميات – الجزء الثاني]https://librebooks.org/tafheem-alkhawazimyat-p2/) - جمال بن نوار (PDF)
+* [تفهيم الخوارزميات – الجزء الأول](https://librebooks.org/tafheem-alkhawazimyat/) - جمال بن نوار (PDF)
+
+
 ### JavaScript
 
 * [تعلم JavaScript‏](https://itwadi.com/node/3002) - Cody Lindley, عبداللطيف ايمش (PDF)