Called by the server (via the service method) to allow a
servlet to handle a GET request.
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.
When overriding this method, read the request data, write the response
headers, get the response's writer or output stream object, and finally,
write the response data. It's best to include content type and encoding.
When using a PrintWriter object to return the response, set
the content type before accessing the PrintWriter object.
The servlet container must write the headers before committing the
response, because in HTTP the headers must be sent before the response
body.
Where possible, set the Content-Length header (with the
ServletResponse.setContentLength(int) method), to allow
the servlet container to use a persistent connection to return its
response to the client, improving performance. The content length is
automatically set if the entire response fits inside the response 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 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 client
- Throws:
ServletException - if the request for the GET could not be handled
java.io.IOException - if an input or output error is detected when the servlet
handles the GET request- See Also:
ServletResponse.setContentType(java.lang.String)