File Information
Library: Net
Package: Messages
Header: Poco/Net/MessageHeader.h
Description
A collection of name-value pairs that are used in various internet protocols like HTTP and SMTP.
The name is case-insensitive.
There can be more than one name-value pair with the same name.
MessageHeader supports writing and reading the header data in RFC 2822 format.
The maximum number of fields can be restricted by calling setFieldLimit(). This is useful to defend against certain kinds of denial-of-service attacks. The limit is only enforced when parsing header fields from a stream, not when programmatically adding them. The default limit is 100.
Inheritance
Direct Base Classes: NameValueCollection
All Base Classes: NameValueCollection
Known Derived Classes: HTTPServerRequest, HTTPMessage, HTTPServerResponse, MailMessage, HTTPServerRequestImpl, HTTPServerResponseImpl, HTTPRequest, HTTPResponse
Member Summary
Member Functions: decodeRFC2047, decodeWord, getFieldLimit, hasToken, operator =, quote, read, setFieldLimit, splitElements, splitParameters, write
Inherited Functions: add, begin, clear, empty, end, erase, find, get, has, operator =, operator [], set, size, swap
Constructors
MessageHeader
Creates the MessageHeader.
MessageHeader
MessageHeader(
const MessageHeader & messageHeader
);
Creates the MessageHeader by copying another one.
Destructor
~MessageHeader 
virtual ~MessageHeader();
Destroys the MessageHeader.
Member Functions
decodeRFC2047 
static void decodeRFC2047(
const std::string & ins,
std::string & outs,
const std::string & charset = "UTF-8"
);
decodeWord
static std::string decodeWord(
const std::string & text,
const std::string & charset = "UTF-8"
);
Decode RFC2047 string.
getFieldLimit
int getFieldLimit() const;
Returns the maximum number of header fields allowed.
See setFieldLimit() for more information.
hasToken
bool hasToken(
const std::string & fieldName,
const std::string & token
) const;
Returns true iff the field with the given fieldName contains the given token. Tokens in a header field are expected to be comma-separated and are case insensitive.
operator =
MessageHeader & operator = (
const MessageHeader & messageHeader
);
Assigns the content of another MessageHeader.
quote
static void quote(
const std::string & value,
std::string & result,
bool allowSpace = false
);
Checks if the value must be quoted. If so, the value is appended to result, enclosed in double-quotes. Otherwise, the value is appended to result as-is.
read
virtual void read(
std::istream & istr
);
Reads the message header from the given input stream.
See write() for the expected format. Also supported is folding of field content, according to section 2.2.3 of RFC 2822.
Reading stops at the first empty line (a line only containing \r\n or \n), as well as at the end of the stream.
Some basic sanity checking of the input stream is performed.
Throws a MessageException if the input stream is malformed.
setFieldLimit
void setFieldLimit(
int limit
);
Sets the maximum number of header fields allowed. This limit is used to defend certain kinds of denial-of-service attacks. Specify 0 for unlimited (not recommended).
The default limit is 100.
splitElements
static void splitElements(
const std::string & s,
std::vector < std::string > & elements,
bool ignoreEmpty = true
);
Splits the given string into separate elements. Elements are expected to be separated by commas.
For example, the string
text/plain; q=0.5, text/html, text/x-dvi; q=0.8
is split into the elements
text/plain; q=0.5 text/html text/x-dvi; q=0.8
Commas enclosed in double quotes do not split elements.
If ignoreEmpty is true, empty elements are not returned.
splitParameters
static void splitParameters(
const std::string & s,
std::string & value,
NameValueCollection & parameters
);
Splits the given string into a value and a collection of parameters. Parameters are expected to be separated by semicolons.
Enclosing quotes of parameter values are removed.
For example, the string
multipart/mixed; boundary="MIME_boundary_01234567"
is split into the value
multipart/mixed
and the parameter
boundary -> MIME_boundary_01234567
splitParameters
static void splitParameters(
const std::string::const_iterator & begin,
const std::string::const_iterator & end,
NameValueCollection & parameters
);
Splits the given string into a collection of parameters. Parameters are expected to be separated by semicolons.
Enclosing quotes of parameter values are removed.
write
virtual void write(
std::ostream & ostr
) const;
Writes the message header to the given output stream.
The format is one name-value pair per line, with name and value separated by a colon and lines delimited by a carriage return and a linefeed character. See RFC 2822 for details.