Receives an HTTP GET request from the protected
service
method and handles the request.
The GET method allows a client to read information
from the Web server, passing a query string appended
to an URL to tell the server what information
to return.
Overriding this method to support a GET request also
automatically supports an HTTP HEAD request. A HEAD
request is a GET request that returns no body in the
response, only the request header fields.
If you override this method, you should read data from
the request, set entity headers in the response,
access the writer or output stream object, and finally,
write the response data. When you set headers, be
sure to include content type and encoding. If you use
a PrintWriter
object to return the response,
you must set the content type before you access the
PrintWriter
object.
The servlet engine must write the headers before
the response data, because the headers can be flushed
at any time after the data is written.
If you can set the Content-Length header (with the
javax.servlet.ServletResponse.#contentType
method),
the servlet
can use a persistent connection to return its response
to the client, improving performance dramatically.
If you cannot set Content-Length, you can sometimes avoid
the performance penalty if the response fits in an internal
buffer.
The GET method should be safe, that is, without
any side effects for which users are held responsible.
For example, most form queries have no side effects.
If a client request is intended to change stored data,
the request should use some other HTTP method.
The GET method should also be idempotent, meaning
that it can be safely repeated. Sometimes making a
method safe also makes it idempotent. For example,
repeating queries is both safe and idempotent, but
buying a product online or modifying data is neither
safe nor idempotent.
If the request is incorrectly formatted, doGet
returns an HTTP BAD_REQUEST message.
- Overrides:
- doGet in class javax.servlet.http.HttpServlet
Tags copied from class: javax.servlet.http.HttpServlet
- Parameters:
req
- an HttpServletRequest
object that
contains the request the client has made
of the servletresp
- an HttpServletResponse
object that
contains the response the servlet sends
to the object- Throws:
- java.io.IOException - if an input or output error is
detected when the servlet handles
the GET request
- javax.servlet.ServletException - if the request for the GET
could not be handled
- See Also:
ServletResponse.setContentType(java.lang.String)