Package org.apache.catalina.filters
Class SessionInitializerFilter
- java.lang.Object
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- org.apache.catalina.filters.SessionInitializerFilter
 
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- All Implemented Interfaces:
- Filter
 
 public class SessionInitializerFilter extends java.lang.Object implements Filter AFilterthat initializes theHttpSessionfor theHttpServletRequestby calling its getSession() method.This is required for some operations with WebSocket requests, where it is too late to initialize the HttpSession object, and the current Java WebSocket specification does not provide a way to do so. 
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Constructor SummaryConstructors Constructor Description SessionInitializerFilter()
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Method SummaryAll Methods Instance Methods Concrete Methods Modifier and Type Method Description voiddestroy()Called by the web container to indicate to a filter that it is being taken out of service.voiddoFilter(ServletRequest request, ServletResponse response, FilterChain chain)CallsHttpServletRequest's getSession() to initialize the HttpSession and continues processing the chain.voidinit(FilterConfig filterConfig)Called by the web container to indicate to a filter that it is being placed into service.
 
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Method Detail- 
doFilterpublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws java.io.IOException, ServletException CallsHttpServletRequest's getSession() to initialize the HttpSession and continues processing the chain.- Specified by:
- doFilterin interface- Filter
- Parameters:
- request- The request to process
- response- The response associated with the request
- chain- Provides access to the next filter in the chain for this filter to pass the request and response to for further processing
- Throws:
- java.io.IOException- if an I/O error occurs during this filter's processing of the request
- ServletException- if the processing fails for any other reason
 
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initpublic void init(FilterConfig filterConfig) throws ServletException Description copied from interface:javax.servlet.FilterCalled by the web container to indicate to a filter that it is being placed into service. The servlet container calls the init method exactly once after instantiating the filter. The init method must complete successfully before the filter is asked to do any filtering work.The web container cannot place the filter into service if the init method either: - Throws a ServletException
- Does not return within a time period defined by the web container
 - Specified by:
- initin interface- Filter
- Parameters:
- filterConfig- The configuration information associated with the filter instance being initialised
- Throws:
- ServletException- if the initialisation fails
 
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destroypublic void destroy() Description copied from interface:javax.servlet.FilterCalled by the web container to indicate to a filter that it is being taken out of service. This method is only called once all threads within the filter's doFilter method have exited or after a timeout period has passed. After the web container calls this method, it will not call the doFilter method again on this instance of the filter.
 
 This method gives the filter an opportunity to clean up any resources that are being held (for example, memory, file handles, threads) and make sure that any persistent state is synchronized with the filter's current state in memory.
 
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