org.apache.http.message
Class BasicLineParser

java.lang.Object
  org.apache.http.message.BasicLineParser

All Implemented Interfaces:

LineParser

@Contract(threading=IMMUTABLE)
public class BasicLineParser
extends Object
implements LineParser

Basic parser for lines in the head section of an HTTP message. There are individual methods for parsing a request line, a status line, or a header line. The lines to parse are passed in memory, the parser does not depend on any specific IO mechanism. Instances of this class are stateless and thread-safe. Derived classes MUST maintain these properties.

Note: This class was created by refactoring parsing code located in various other classes. The author tags from those other classes have been replicated here, although the association with the parsing code taken from there has not been traced.

Since:

4.0

Field Summary

static BasicLineParser	DEFAULT Deprecated. (4.3) use INSTANCE
static BasicLineParser	INSTANCE
protected ProtocolVersion	protocol A version of the protocol to parse.

Constructor Summary

BasicLineParser()
Creates a new line parser for HTTP.

BasicLineParser(ProtocolVersion proto)
Creates a new line parser for the given HTTP-like protocol.

Method Summary

protected ProtocolVersion	createProtocolVersion(int major, int minor) Creates a protocol version.
protected RequestLine	createRequestLine(String method, String uri, ProtocolVersion ver) Instantiates a new request line.
protected StatusLine	createStatusLine(ProtocolVersion ver, int status, String reason) Instantiates a new status line.
boolean	hasProtocolVersion(CharArrayBuffer buffer, ParserCursor cursor) Checks whether there likely is a protocol version in a line.
Header	parseHeader(CharArrayBuffer buffer) Creates a header from a line.
static Header	parseHeader(String value, LineParser parser)
ProtocolVersion	parseProtocolVersion(CharArrayBuffer buffer, ParserCursor cursor) Parses the textual representation of a protocol version.
static ProtocolVersion	parseProtocolVersion(String value, LineParser parser)
RequestLine	parseRequestLine(CharArrayBuffer buffer, ParserCursor cursor) Parses a request line.
static RequestLine	parseRequestLine(String value, LineParser parser)
StatusLine	parseStatusLine(CharArrayBuffer buffer, ParserCursor cursor) Parses a status line.
static StatusLine	parseStatusLine(String value, LineParser parser)
protected void	skipWhitespace(CharArrayBuffer buffer, ParserCursor cursor) Helper to skip whitespace.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT

@Deprecated
public static final BasicLineParser DEFAULT

Deprecated. (4.3) use INSTANCE

A default instance of this class, for use as default or fallback. Note that BasicLineParser is not a singleton, there can be many instances of the class itself and of derived classes. The instance here provides non-customized, default behavior.

INSTANCE

public static final BasicLineParser INSTANCE

protocol

protected final ProtocolVersion protocol

A version of the protocol to parse. The version is typically not relevant, but the protocol name.

Constructor Detail

BasicLineParser

public BasicLineParser(ProtocolVersion proto)

Creates a new line parser for the given HTTP-like protocol.

Parameters:

proto - a version of the protocol to parse, or null for HTTP. The actual version is not relevant, only the protocol name.

BasicLineParser

public BasicLineParser()

Creates a new line parser for HTTP.

Method Detail

parseProtocolVersion

public static ProtocolVersion parseProtocolVersion(String value,
                                                   LineParser parser)
                                            throws ParseException

Throws:

ParseException

parseProtocolVersion

public ProtocolVersion parseProtocolVersion(CharArrayBuffer buffer,
                                            ParserCursor cursor)
                                     throws ParseException

Description copied from interface: LineParser

Parses the textual representation of a protocol version. This is needed for parsing request lines (last element) as well as status lines (first element).

Specified by:

parseProtocolVersion in interface LineParser

Parameters:

buffer - a buffer holding the protocol version to parse

cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation

Returns:

the parsed protocol version

Throws:

ParseException - in case of a parse error

createProtocolVersion

protected ProtocolVersion createProtocolVersion(int major,
                                                int minor)

Creates a protocol version. Called from parseProtocolVersion(java.lang.String, org.apache.http.message.LineParser).

Parameters:

major - the major version number, for example 1 in HTTP/1.0

minor - the minor version number, for example 0 in HTTP/1.0

Returns:

the protocol version

hasProtocolVersion

public boolean hasProtocolVersion(CharArrayBuffer buffer,
                                  ParserCursor cursor)

Description copied from interface: LineParser

Checks whether there likely is a protocol version in a line. This method implements a heuristic to check for a likely protocol version specification. It does not guarantee that LineParser.parseProtocolVersion(org.apache.http.util.CharArrayBuffer, org.apache.http.message.ParserCursor) would not detect a parse error. This can be used to detect garbage lines before a request or status line.

Specified by:

hasProtocolVersion in interface LineParser

Parameters:

buffer - a buffer holding the line to inspect

cursor - the cursor at which to check for a protocol version, or negative for "end of line". Whether the check tolerates whitespace before or after the protocol version is implementation dependent.

Returns:

true if there is a protocol version at the argument index (possibly ignoring whitespace), false otherwise

parseRequestLine

public static RequestLine parseRequestLine(String value,
                                           LineParser parser)
                                    throws ParseException

Throws:

ParseException

parseRequestLine

public RequestLine parseRequestLine(CharArrayBuffer buffer,
                                    ParserCursor cursor)
                             throws ParseException

Parses a request line.

Specified by:

parseRequestLine in interface LineParser

Parameters:

buffer - a buffer holding the line to parse

cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation

Returns:

the parsed request line

Throws:

ParseException - in case of a parse error

createRequestLine

protected RequestLine createRequestLine(String method,
                                        String uri,
                                        ProtocolVersion ver)

Instantiates a new request line. Called from parseRequestLine(java.lang.String, org.apache.http.message.LineParser).

Parameters:

method - the request method

uri - the requested URI

ver - the protocol version

Returns:

a new status line with the given data

parseStatusLine

public static StatusLine parseStatusLine(String value,
                                         LineParser parser)
                                  throws ParseException

Throws:

ParseException

parseStatusLine

public StatusLine parseStatusLine(CharArrayBuffer buffer,
                                  ParserCursor cursor)
                           throws ParseException

Description copied from interface: LineParser

Parses a status line.

Specified by:

parseStatusLine in interface LineParser

Parameters:

buffer - a buffer holding the line to parse

cursor - the parser cursor containing the current position and the bounds within the buffer for the parsing operation

Returns:

the parsed status line

Throws:

ParseException - in case of a parse error

createStatusLine

protected StatusLine createStatusLine(ProtocolVersion ver,
                                      int status,
                                      String reason)

Instantiates a new status line. Called from parseStatusLine(java.lang.String, org.apache.http.message.LineParser).

Parameters:

ver - the protocol version

status - the status code

reason - the reason phrase

Returns:

a new status line with the given data

parseHeader

public static Header parseHeader(String value,
                                 LineParser parser)
                          throws ParseException

Throws:

ParseException

parseHeader

public Header parseHeader(CharArrayBuffer buffer)
                   throws ParseException

Description copied from interface: LineParser

Creates a header from a line. The full header line is expected here. Header continuation lines must be joined by the caller before invoking this method.

Specified by:

parseHeader in interface LineParser

Parameters:

buffer - a buffer holding the full header line. This buffer MUST NOT be re-used afterwards, since the returned object may reference the contents later.

Returns:

the header in the argument buffer. The returned object MAY be a wrapper for the argument buffer. The argument buffer MUST NOT be re-used or changed afterwards.

Throws:

ParseException - in case of a parse error

skipWhitespace

protected void skipWhitespace(CharArrayBuffer buffer,
                              ParserCursor cursor)

Helper to skip whitespace.