Jsp lifecycle
- 1. JSP - Lifecycle Prof. Neeraj Bhargava Kapil Chauhan Department of Computer Science School of Engineering & Systems Sciences MDS University, Ajmer
- 2. JSP - Lifecycle A JSP life cycle is defined as the process from its creation till the destruction. This is similar to a servlet life cycle with an additional step which is required to compile a JSP into servlet. The following are the paths followed by a JSP − Compilation Initialization Execution Cleanup
- 3. Lifecycle
- 4. JSP Compilation When a browser asks for a JSP, the JSP engine first checks to see whether it needs to compile the page. If the page has never been compiled, or if the JSP has been modified since it was last compiled, the JSP engine compiles the page.
- 5. JSP Initialization When a container loads a JSP it invokes the jspInit() method before servicing any requests. If you need to perform JSP-specific initialization, override the jspInit() method − public void jspInit(){ // Initialization code... }
- 6. JSP Execution This phase of the JSP life cycle represents all interactions with requests until the JSP is destroyed. Whenever a browser requests a JSP and the page has been loaded and initialized, the JSP engine invokes the _jspService() method in the JSP. The _jspService() method takes an HttpServletRequest and an HttpServletResponse as its parameters as follows − void _jspService(HttpServletRequest request, HttpServletResponse response) { // Service handling code... }
- 7. JSP Cleanup The destruction phase of the JSP life cycle represents when a JSP is being removed from use by a container. The jspDestroy() method is the JSP equivalent of the destroy method for servlets. Override jspDestroy when you need to perform any cleanup, such as releasing database connections or closing open files. The jspDestroy() method has the following form − public void jspDestroy() { // Your cleanup code goes here. }