| Class 2 |
Intermediate Java 30-IT-397 |
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Servlets
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Servlets are Java programs that generate dynamic HTML.
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When translated, JSPs become servlets.
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Servlets retrieve information from a submitted web page via the GET or
POST methods.
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These methods are assigned in the METHOD parameter of the HTML FORM tag.
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GET sends the information as name-value pairs in the URL.
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This makes debugging easy, but it also makes it easy for users to manipulate
the values.
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It is limited to the maximum length of the URL.
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POST sends information via an environment variable.
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Servlets extend HttpServlet, which extends Servlet.
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Override doGet() if you wish to process via the GET method.
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Override doPost() if you wish to process via the POST method.
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These methods take two arguments:
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HttpServletRequest: use this to find incoming data.
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HttpServletResponse: use this to set response information, and to get an
output stream.
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And they throw two exceptions, which must be caught.
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ServletException
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IOException
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And, you must import these packages:
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javax.servlet.*;
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java.io.*;
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javax.servlet.http.*;
Your First Servlet
Created by: Brandan Jones
December 20, 2001