Servlets

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Servlets

• Java Web Components

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What Well Cover

• What is a servlet
• Servlet Life Cycle
• Information Sharing
• Service methods
• Filters
• Other resources
• Client State
• Finalization

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What is a Servlet

• Java based web component
• Servlet advantages
• Managed by a container
• Generates dynamic content
• Client interaction via request/response
• Servlet containers/servlet engines

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Servlet Life Cycle

• New servlet instance in container
• Init() method
• Static initializers
• Error conditions on the init
• Handling requests
• Multithreading
• Errors handling requests

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Information Sharing

• Scope objects
• Web context
• Session object
• Request object
• Page object
• Shared Resources
• Database access

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Service Methods

• Service methods provide access to the services of
  the servlet or Jsp.
• Requests from the client implement the
  ServletRequest interface.
• Service methods include the ServletRequest and
  the ServletResponse.
• HttpServletResponse includes fields representing
  HTTP headers

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Filters

• Programming Filters
• Programming Customized Requests and Responses
• Specifying Filter Mappings

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Other Resources

• Invoking other resources
• Including other resources in the response
• Transferring control to another web component
• Accessing the Web Context

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Client State

• Accessing a Session
• Associating objects with a session
• Session Management
• Session Tracking

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Finalization

• Finalizing a servlet
• Tracking service requests
• Notifying Methods to shut down
• Creating polite long-running methods

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What We Covered

• What is a servlet
• Servlet Life Cycle
• Information Sharing
• Service methods
• Filters
• Other resources
• Client State
• Finalization