www.gusucode.com > external 工具箱matlab源码程序 > external/interfaces/webservices/restful/websave.m
function filename = websave(filename, url, varargin)
%WEBSAVE Save content from RESTful web service to file
%
% Syntax
% ------
% OUTFILENAME = WEBSAVE(FILENAME,URL)
% OUTFILENAME = WEBSAVE(FILENAME,URL,QueryName1,QueryValue1, ...)
% OUTFILENAME = WEBSAVE(__,OPTIONS)
%
% Description
% ------------
% OUTFILENAME = WEBSAVE(FILENAME,URL) saves content from the web service
% specified by the string URL to the file FILENAME. If URL indicates a
% file, and FILENAME does not contain the same extension, then the
% extension of URL is appended to FILENAME. WEBSAVE returns the resultant
% name in the string OUTFILENAME, which also includes the full path to
% the file. WEBSAVE sets HTTP request parameters with the default
% property values of WEBOPTIONS and uses the HTTP GET method to read
% content from URL.
%
% OUTFILENAME = WEBSAVE(FILENAME,URL,QueryName1,QueryValue1, ...) appends
% additional RESTful web service query parameters, specified by
% QueryName1, QueryValue1, ..., to URL. These name, value pair arguments
% set query parameters in an HTTP GET operation. The parameters supported
% by a web service are defined in the service's documentation. WEBSAVE
% adds parameters to URL using the "&name=value" construct. However, if
% URL does not contain a "?" character, then WEBSAVE adds the first
% name, value pair as "?name=value". WEBSAVE still adds all following
% parameters as "&name=value". Numeric and logical values are encoded as
% strings using NUM2STR.
%
% OUTFILENAME = WEBSAVE(__,OPTIONS) sets HTTP request parameters with the
% property values of the WEBOPTIONS object OPTIONS. The ContentType and
% ContentReader property values are ignored because the purpose of
% WEBSAVE is to save content in its original format to a file. Set the
% RequestMethod property of OPTIONS to 'post' if you need to use the HTTP
% POST method when obtaining data from a RESTful web service.
%
% Input Arguments
% ---------------
%
% Name Description Data Type
% ---- -------------------- ---------
% FILENAME
% Name of file to save content. string
%
% URL Web address of content including the string
% transfer protocol, http or https.
% The URL is automatically encoded.
%
% QueryName
% Name of additional web service parameter string
% to append to URL.
%
% QueryValue
% Value of additional web service parameter string; vector of
% to append to URL. If you specify a datetime numeric, logical
% you must specify its Format property as or datetime; 2-D
% expected by the web service. If it is a array of char; or
% non-scalar vector or cell vector, or char cell array containing
% array with more than one row, the value is strings or numeric,
% processed according to the ArrayFormat property logical or datetime
% of WEBOPTIONS. scalars
%
% OPTIONS
% Other options used to connect to web scalar WEBOPTIONS
% service. object
%
% % Example 1
% % ---------
% % Download the HTML page on the MATLAB(R) Central File Exchange that
% % lists submissions for sensor-data-acquisition to a file.
% url = 'http://www.mathworks.com/matlabcentral/fileexchange';
% searchTerm = 'sensor-data-acquisition';
% filename = [searchTerm '.html'];
% websave(filename,url,'term',searchTerm);
%
% See also DATETIME, WEBOPTIONS, WEBREAD, WEBWRITE
% Copyright 2014-2015 The MathWorks, Inc.
% Validate filename.
validateattributes(filename, {'char'}, {'nonempty', 'vector'}, ...
mfilename, 'FILENAME');
filename = filename(:)';
% Parse the inputs.
[queryParams, options] = parseInputs(mfilename, varargin);
% Encode inputs.
[url, postData, options] = encodeInputs(url, queryParams, options);
% Open the HTTP connection and obtain the connection content type.
connection = openHTTPConnection(url, options, postData);
% Append an extension to filename, if needed.
filename = appendUrlExtension(url, filename, connection.ContentType);
% Ensure that the file can be written and return full path to the file.
filename = validateFileAccess(filename);
% Copy the content from the web service to the file.
copyContentToFile(connection, filename);
%--------------------------------------------------------------------------
function filename = appendUrlExtension(url, filename, contentType)
% Append the extension of URL, if URL does not contain ? and the filename
% does not match the URL extension. Add .html if content type is HTML and
% the extension is not added.
if isempty(strfind(url, '?'))
% There are no URL query parameters, obtain the extension of URL.
[~, ~, urlExt] = fileparts(url);
% Obtain the extension of the file.
[~,~,fileExt] = fileparts(filename);
% Determine if content type is HTML.
if ~isempty(strfind(contentType, 'html'))
% Content type is HTML. Preserve .htm or .html if provided,
% otherwise add .html
htmlExt = {'.htm','.html'};
index = strncmpi(fileExt, htmlExt, length(fileExt));
if ~any(index) || isempty(fileExt)
% The filename does not have an extension.
index = strncmp(urlExt, htmlExt, length(urlExt));
if any(index) && isscalar(find(index))
urlExt = [htmlExt{index}];
else
urlExt = '.html';
end
filename = [filename urlExt];
end
elseif ~isempty(urlExt) && isempty(fileExt)
% Content is not HTML.
% Append extension of the URL if filename doesn't have an extension
filename = [filename urlExt];
end
end
%--------------------------------------------------------------------------
function filename = validateFileAccess(filename)
% Ensure that the file is writable and return full path name.
if exist(filename,'file')
fileIsNew = false;
else
fileIsNew = true;
end
% Validate the file can be opened. This results in a file on the disk.
fid = fopen(filename,'w');
if fid == -1
e = MException(message('MATLAB:webservices:InvalidFilename',filename));
throwAsCaller(e);
end
fclose(fid);
% Use fopen to obtain full path to the file and to translate ~ or ~username
% on Unix.
fid = fopen(filename);
filename = fopen(fid);
fclose(fid);
if fileIsNew && exist(filename,'file')
% Remove this file in case an error is issued later.
delete(filename)
end