21.3 Java4535r-review  (Page 2/2)

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Question 11

True or False?

Overriding the doGet method to support the GET command also automatically supports the HTTP HEAD command.

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Question 12

True or False?

The fundamental purpose of the GET command makes it possible for the client to get something from the server. When you override the doGet method, you should, as a minimum:

• Read data from the request
• Construct the proper headers in the response
• Gain access to either the writer or the output stream (depending on whether the material to be returned is text or binary data)
• Write the response data

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Question 13

True or False?

The headers that you create in your overridden doGet method should include content type and encoding. The content type must be set beforethe writer is accessed. The setContentType method of the response object can be called to set the content type. The getWriter method of the response object can be called to get access to the output stream.

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Question 14

True or False?

The class definition for an HTTP servlet extends the JavaHttpServlet class.

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Question 15

True or False?

Servlets typically process requests from multiple clients concurrently in a multithreaded manner. However, it is possible to write servlets that arerestricted to single-threaded operation by implementing the SingleThreadModel interface.

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Question 16

True or False?

When writing a servlet for multi-threaded operation, you should use the fewest possible number of instance variables, and synchronize access to them if you use them.

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Question 17

True or False?

For servlets that extend the HttpServlet class, the following methods may be overridden to cause your servlet to interact with theclient.

• doGet - for handling GET, conditional GET and HEAD requests
• doPost - for handling POST requests
• doPut - for handling PUT requests
• doDelete - for handling DELETE requests
• doTerminate - for terminating the servlet and returning control to the browser

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What is the meaning of the following two images?

These images were inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at thesame time.

This image was also inserted for the purpose of inserting space between the questions and the answers.

Answers

Answer 17

False.

For servlets that extend the HttpServlet class, the following four methods may be overridden to cause your servlet to interact withthe client.

• doGet - for handling GET, conditional GET and HEAD requests
• doPost - for handling POST requests
• doPut - for handling PUT requests
• doDelete - for handling DELETE requests

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Answer 16

True.

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Answer 15

True.

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Answer 14

False. The class definition for an HTTP servlet extends the HttpServlet class.

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Answer 13

True.

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Answer 12

True.

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Answer 11

True.

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Answer 10

False. The doGet method corresponds to the HTTP GET command. If you don't override the method, the default implementation reports an HTTP BAD_REQUEST error when the browser sends a GET command.

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Answer 9

True.

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Answer 8

True.

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Answer 7

False.

Object references of the following types are passed to a servlet when it called by a client:

• ServletRequest - encapsulates the communication from the client to the server.
• ServletResponse - encapsulates the communication from the servlet back to the client

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Answer 6

True.

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Answer 5

False. All servlets must implement the Servlet interface. You can implement it directly. However, it is more common to implement itindirectly by extending a class that implements the interface (such as HttpServlet ).

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Answer 4

True.

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Answer 3

False. The use of servlets is not restricted to HTTP servers.

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Answer 2

False. You must run your servlet under the control of a Java-enabled server program. Not all HTTP servers support Java servlets.

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Answer 1

True.

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Miscellaneous

This section contains a variety of miscellaneous information.

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