Tell me about the lifecycle methods of JSP.

The JSP lifecycle is managed by the servlet container and consists of the following stages:

Translation: The JSP file is converted into a Java servlet class. This stage occurs when the JSP page is first accessed or when the application is restarted. During this stage, the servlet source code is generated.
Compilation: The generated Java servlet file is compiled into bytecode (.class file).
Loading and Instantiation: The servlet class is loaded into the JVM, and an instance of it is created.
Initialization: The container calls the jspInit() method of the servlet instance. This method is called only once when the JSP page is loaded into memory. Here, any necessary setup or initialization can be performed.
```
// servlet code
public void jspInit() {
    // Initialization code here
}
```
Request Processing: For each request to the JSP page, the container calls the _jspService() method. This method is automatically generated during translation and is responsible for executing the content of the JSP page (including scriptlet tags, expressions, declarations) and creating the response.
```
// servlet code
public void _jspService(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    // Generated code for JSP page processing
}
```
It is important to note that the _jspService method should not be overridden by the developer in JSP (unlike doGet/doPost methods in regular servlets).
Destruction: When the servlet container unloads the JSP page from memory (for example, when stopping the application or restarting the server), the jspDestroy() method is called. This method is also called only once and is used for resource cleanup.
```
// servlet code
public void jspDestroy() {
    // Cleanup code here
}
```

Here is a table summarizing the key lifecycle methods:

Method	Called when...	Called how many times...	Purpose
`jspInit()`	JSP page is loaded and instantiated	Once	Initialization
`_jspService()`	On each request to the JSP page	Multiple times	Request processing and response generation
`jspDestroy()`	JSP page is unloaded from memory	Once	Resource cleanup