非常感谢大家.现在工作正常.服务器找不到文件，因为路径不正确.经过一番试验后，我终于能够通过提供正确的路径从json文件中获取json数据，例如-"TestPortlet3-portlet/js/example.json".最初，我只提供"/example.json"或"users.json".将.json文件保存在正确的文件夹中并提供正确的路径后，我能够显示json数据:)

Thanks a lot everyone. It is working fine now. The server could not find the files because the path was not proper. After experimenting a bit, I was finally able to fetch the json data from the json file by giving a proper path, like - "TestPortlet3-portlet/js/example.json". Initially, I was only giving "/example.json" or "users.json". On keeping the .json file in the correct folder and giving the correct path, I was able to display the json data :)