Servlet - Basic

This exam is based on the ability to use the servlet API for basic tasks. This knowledge is still needed when using a web framework (as Struts, Tapestry, Spring MVC, etc.). This exam is complementary to the JSP Basic and the Struts Basic exams. It requires much less knowledge than the SCWCD certification.

Are not part of the basic exam (but kept for intermed & advanced exams):

Session attribute listeners
Servlet Init params
Servlet Context Listeners
Work with cookies API.
Filters
Request wrapper
Error handling
Security

	Released	Beta	Frozen
Servlet 1 question Write a simple Servlet class that correctly extends the HttpServlet class that correctly overrides the appropriate ancestor method Describe why your servlet must be stateless Explain that the servlet model is multithreaded (1 thread/request) Develop threadsafe servlets by writing stateless servlets (without declared instance variables) Not Covered : Servlet Lifecycle init(), init(config), ...	13	387	51	Add a question Beta questions
Request 3 questions Differentiate GET and POST HTTP methods Explain how parameters are stored in the request : in the URL or in the body of the HTTP request Identify what default HTTP method will be used when clicking on a link, submitting a form Know that HTML Forms can use both GET and POST Know that the `HttpServlet.doGet() & doPost()` are called accordingly. Manipulate request Parameters Write code that retrieves parameters from the `HttpServletRequest` Identify when `getParameter()` will return `null` instead of a valid String Write code that handles multi-valued parameters and retrieves all the values that they contain. Know the correct syntax to pass parameters through a request added to the URL Not covered: Questions regarding attributes should be placed in the "Attributes" category.	29	76	108	Add a question Beta questions
Response 1 question Produce the HTTP response body Obtain a `PrintWriter` from the `HttpServletResponse` object Set the content type of the `HttpServletResponse` and know that it must be set before the content.	12	41	49	Add a question Beta questions
Attributes 2 questions Retrieve and Store attributes in each scope : `HttpServletRequest, HttpSession, ServletContext` Explain that `null` will be returned by the `getAttribute()` if no attribute can be found Write code that iterates through all the attributes of a given scope Remove attributes from a given scope Not covered: Related listeners	19	2	48	Add a question Beta questions
Session 2 questions Understand JSESSIONID mechanism Describe the mechanisms that let the web container bind an incoming request to an existing session cookies URL rewriting hidden field Write code that concatenate the JSESSIONID to a URL using the `HttpServletResponse.encodeURL()` method. Get the session and manipulate it Write code that retrieves an `HttpSession` object either by using the `getSession()` method or by creating a new one if needed using the `getSession(boolean)` method Not covered: Related listeners are not part of this exam, questions regarding attributes should be placed in the "Attributes" objectives.	33	86	63	Add a question Beta questions
Servlet Context 1 question Understand the servlet context scope within a web application Identify the ServletContext instance is unique within a web application Write servlet code that gets a reference to the ServletContext object Not Covered: Questions regarding attributes should be placed in the "Attributes" objectives.	12	20	32	Add a question Beta questions
Structure and Deployment 3 questions Write a simple Deployment Descriptor Configure the web.xml correctly for a basic servlet Write a correct `<servlet>` element ... ... and the corresponding `<servlet-mapping>` element Write correct <load-on-startup> element. Describe a correct directory structure for a WAR file Explain the web.xml must be placed in the WEB-INF directory .class files in the classes directory .jar files in the lib directory Static html files can be placed anywhere except inside the WEB-INF directory Identify which directories are accessible or not to incoming HTTP request URLs Not covered: no questions on context listener nor init parameters	42	29	94	Add a question Beta questions