Are Servlets Thread Safe? How to achieve thread safety in servlets?

HttpServlet init() method and destroy() method are called only once in servlet life cycle, so we don’t need to worry about their synchronization. But service methods such as doGet() or doPost() are getting called in every client request and since servlet uses multithreading, we should provide thread safety in these methods.

If there are any local variables in service methods, we don’t need to worry about their thread safety because they are specific to each thread but if we have a shared resource then we can use synchronization to achieve thread safety in servlets when working with shared resources.