我无法将restful连接到mysql数据库

i'm developing a restful web service ,actually i'm using a file but i want to make a data base connection instead so i can get data from the database instead of a file , i tried to make a database connection but it dosn't work , even the server which is wildfly stopped and stoped deploying the project. this is the files im using:i'm developing a restful web service ,actually