在WEB-INF/lib文件夹中添加mysql-connector-java-5.1.29-bin.jar. 仅将jar添加到您的构建路径中是不够的. 甚至我一开始也遇到同样的问题.

Add the mysql-connector-java-5.1.29-bin.jar in the WEB-INF/lib folder. Its not enough to just add the jar in your built path. Even I had the same issue at the start.