juce::WebInputStream Class Reference

An InputStream which can be used to read from a given URL. More...

#include <juce_WebInputStream.h>

Inheritance diagram for juce::WebInputStream:

Collaboration diagram for juce::WebInputStream:

Classes
class	Listener
	Used to receive callbacks for POST data send progress. More...

Public Member Functions
	WebInputStream (const URL &url, bool addParametersToRequestBody)
	Creates a new WebInputStream which can be used to read from a URL. More...
	~WebInputStream () override
	Destructor. More...
void	cancel ()
	Will cancel a blocking read and prevent any subsequent connection attempts. More...
bool	connect (Listener *listener)
	Wait until the first byte is ready for reading. More...
int64	getNumBytesRemaining ()
	Returns the number of bytes available for reading, or a negative value if the remaining length is not known. More...
int64	getPosition () override
	Returns the offset of the next byte that will be read from the stream. More...
StringPairArray	getRequestHeaders () const
	Returns a StringPairArray of the request headers. More...
StringPairArray	getResponseHeaders ()
	Returns a StringPairArray of response headers. More...
int	getStatusCode ()
	Returns the status code returned by the HTTP server. More...
int64	getTotalLength () override
	Returns the total number of bytes available for reading in this stream. More...
bool	isError () const
	Returns true if there was an error during the connection attempt. More...
bool	isExhausted () override
	Returns true if the stream has no more data to read. More...
int	read (void *destBuffer, int maxBytesToRead) override
	Reads some data from the stream into a memory buffer. More...
ssize_t	read (void *destBuffer, size_t maxBytesToRead)
virtual bool	readBool ()
	Reads a boolean from the stream. More...
virtual char	readByte ()
	Reads a byte from the stream. More...
virtual int	readCompressedInt ()
	Reads an encoded 32-bit number from the stream using a space-saving compressed format. More...
virtual double	readDouble ()
	Reads eight bytes as a 64-bit floating point value. More...
virtual double	readDoubleBigEndian ()
	Reads eight bytes as a 64-bit floating point value. More...
virtual String	readEntireStreamAsString ()
	Tries to read the whole stream and turn it into a string. More...
virtual float	readFloat ()
	Reads four bytes as a 32-bit floating point value. More...
virtual float	readFloatBigEndian ()
	Reads four bytes as a 32-bit floating point value. More...
virtual int	readInt ()
	Reads four bytes from the stream as a little-endian 32-bit value. More...
virtual int64	readInt64 ()
	Reads eight bytes from the stream as a little-endian 64-bit value. More...
virtual int64	readInt64BigEndian ()
	Reads eight bytes from the stream as a big-endian 64-bit value. More...
virtual int	readIntBigEndian ()
	Reads four bytes from the stream as a big-endian 32-bit value. More...
virtual size_t	readIntoMemoryBlock (MemoryBlock &destBlock, ssize_t maxNumBytesToRead=-1)
	Reads from the stream and appends the data to a MemoryBlock. More...
virtual String	readNextLine ()
	Reads a UTF-8 string from the stream, up to the next linefeed or carriage return. More...
virtual short	readShort ()
	Reads two bytes from the stream as a little-endian 16-bit value. More...
virtual short	readShortBigEndian ()
	Reads two bytes from the stream as a little-endian 16-bit value. More...
virtual String	readString ()
	Reads a zero-terminated UTF-8 string from the stream. More...
bool	setPosition (int64 wantedPos) override
	Tries to move the current read position of the stream. More...
virtual void	skipNextBytes (int64 numBytesToSkip)
	Reads and discards a number of bytes from the stream. More...
WebInputStream &	withConnectionTimeout (int timeoutInMs)
	Specify the connection time-out. More...
WebInputStream &	withCustomRequestCommand (const String &customRequestCommand)
	Override the HTTP command that is sent. More...
WebInputStream &	withExtraHeaders (const String &extraHeaders)
	Add extra headers to the HTTP request. More...
WebInputStream &	withNumRedirectsToFollow (int numRedirects)
	Specify the number of redirects to be followed. More...

Static Private Member Functions
static void	createHeadersAndPostData (const URL &, String &, MemoryBlock &, bool)
static StringPairArray	parseHttpHeaders (const String &)

Private Attributes
bool	hasCalledConnect = false
std::unique_ptr< Pimpl >	pimpl

Friends
class	Pimpl

Detailed Description

An InputStream which can be used to read from a given URL.

@tags{Core}

Constructor & Destructor Documentation

WebInputStream()

juce::WebInputStream::WebInputStream	(	const URL &	url,
		bool	addParametersToRequestBody
	)

Creates a new WebInputStream which can be used to read from a URL.

Parameters

url	the URL that should be retrieved. This parameter may also contain POST data and/or parameters.
addParametersToRequestBody	specifies whether any URL parameters that have been set will be transferred via the request body data or added to the URL address. This will also determine whether a POST or GET command will be used if a custom command is not set.

~WebInputStream()

juce::WebInputStream::~WebInputStream ( )

override

Destructor.

Member Function Documentation

cancel()

void juce::WebInputStream::cancel

(

)

Will cancel a blocking read and prevent any subsequent connection attempts.

connect()

bool juce::WebInputStream::connect

(

Listener *

listener

)

Wait until the first byte is ready for reading.

This method will attempt to connect to the URL given in the constructor and block until the status code and all response headers have been received or an error has occurred.

Note that most methods will call connect() internally if they are called without an established connection. Therefore, it is not necessary to explicitly call connect unless you would like to use a custom listener.

After a successful call to connect(), getResponseHeaders(), getTotalLength() and getStatusCode() will all be non-blocking.

Parameters

listener

a listener to receive progress callbacks on the status of a POST data upload.

See also

getResponseHeaders, getTotalLength, getStatusCode

createHeadersAndPostData()

static void juce::WebInputStream::createHeadersAndPostData ( const URL &  , String &  , MemoryBlock &  , bool    )

staticprivate

getNumBytesRemaining()

int64 juce::InputStream::getNumBytesRemaining ( )

inherited

Returns the number of bytes available for reading, or a negative value if the remaining length is not known.

See also

getTotalLength

getPosition()

int64 juce::WebInputStream::getPosition ( )

overridevirtual

Returns the offset of the next byte that will be read from the stream.

See also

setPosition

Implements juce::InputStream.

getRequestHeaders()

StringPairArray juce::WebInputStream::getRequestHeaders

(

)

const

Returns a StringPairArray of the request headers.

getResponseHeaders()

StringPairArray juce::WebInputStream::getResponseHeaders

(

)

Returns a StringPairArray of response headers.

If getResponseHeaders() is called without an established connection, then getResponseHeaders() will call connect internally and block until connect returns - either due to a successful connection or a connection error.

See also

connect

getStatusCode()

int juce::WebInputStream::getStatusCode

(

)

Returns the status code returned by the HTTP server.

If getStatusCode() is called without an established connection, then getStatusCode() will call connect internally and block until connect returns - either due to a successful connection or a connection error.

See also

connect

getTotalLength()

int64 juce::WebInputStream::getTotalLength ( )

overridevirtual

Returns the total number of bytes available for reading in this stream.

Note that this is the number of bytes available from the start of the stream, not from the current position.

If getTotalLength() is called without an established connection, then getTotalLength() will call connect internally and block until connect returns - either due to a successful connection or a connection error.

If the size of the stream isn't actually known, this will return -1.

Implements juce::InputStream.

isError()

bool juce::WebInputStream::isError

(

)

const

Returns true if there was an error during the connection attempt.

isExhausted()

bool juce::WebInputStream::isExhausted ( )

overridevirtual

Returns true if the stream has no more data to read.

Implements juce::InputStream.

parseHttpHeaders()

static StringPairArray juce::WebInputStream::parseHttpHeaders ( const String &  )

staticprivate

read() [1/2]

int juce::WebInputStream::read ( void *  destBuffer, int  maxBytesToRead  )

overridevirtual

Reads some data from the stream into a memory buffer.

This method will block until the maxBytesToRead bytes are available.

This method calls connect() internally if the connection hasn't already been established.

Parameters

destBuffer	the destination buffer for the data. This must not be null.
maxBytesToRead	the maximum number of bytes to read - make sure the memory block passed in is big enough to contain this many bytes. This value must not be negative.

Returns

the actual number of bytes that were read, which may be less than maxBytesToRead if the stream is exhausted before it gets that far

Implements juce::InputStream.

read() [2/2]

ssize_t juce::InputStream::read ( void *  destBuffer, size_t  maxBytesToRead  )

inherited

readBool()

virtual bool juce::InputStream::readBool ( )

virtualinherited

Reads a boolean from the stream.

The bool is encoded as a single byte - non-zero for true, 0 for false. If the stream is exhausted, this will return false.

See also

OutputStream::writeBool

readByte()

virtual char juce::InputStream::readByte ( )

virtualinherited

Reads a byte from the stream.

If the stream is exhausted, this will return zero.

See also

OutputStream::writeByte

readCompressedInt()

virtual int juce::InputStream::readCompressedInt ( )

virtualinherited

Reads an encoded 32-bit number from the stream using a space-saving compressed format.

For small values, this is more space-efficient than using readInt() and OutputStream::writeInt() The format used is: number of significant bytes + up to 4 bytes in little-endian order.

See also

OutputStream::writeCompressedInt()

readDouble()

virtual double juce::InputStream::readDouble ( )

virtualinherited

Reads eight bytes as a 64-bit floating point value.

The raw 64-bit encoding of the double is read from the stream as a little-endian int64. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeDouble, readFloat

readDoubleBigEndian()

virtual double juce::InputStream::readDoubleBigEndian ( )

virtualinherited

Reads eight bytes as a 64-bit floating point value.

The raw 64-bit encoding of the double is read from the stream as a big-endian int64. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeDoubleBigEndian, readFloatBigEndian

readEntireStreamAsString()

virtual String juce::InputStream::readEntireStreamAsString ( )

virtualinherited

Tries to read the whole stream and turn it into a string.

This will read from the stream's current position until the end-of-stream. It can read from UTF-8 data, or UTF-16 if it detects suitable header-bytes.

readFloat()

virtual float juce::InputStream::readFloat ( )

virtualinherited

Reads four bytes as a 32-bit floating point value.

The raw 32-bit encoding of the float is read from the stream as a little-endian int. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeFloat, readDouble

readFloatBigEndian()

virtual float juce::InputStream::readFloatBigEndian ( )

virtualinherited

Reads four bytes as a 32-bit floating point value.

The raw 32-bit encoding of the float is read from the stream as a big-endian int. If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeFloatBigEndian, readDoubleBigEndian

readInt()

virtual int juce::InputStream::readInt ( )

virtualinherited

Reads four bytes from the stream as a little-endian 32-bit value.

If the next four bytes are byte1 to byte4, this returns (byte1 | (byte2 << 8) | (byte3 << 16) | (byte4 << 24)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeInt, readIntBigEndian

readInt64()

virtual int64 juce::InputStream::readInt64 ( )

virtualinherited

Reads eight bytes from the stream as a little-endian 64-bit value.

If the next eight bytes are byte1 to byte8, this returns (byte1 | (byte2 << 8) | (byte3 << 16) | (byte4 << 24) | (byte5 << 32) | (byte6 << 40) | (byte7 << 48) | (byte8 << 56)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeInt64, readInt64BigEndian

readInt64BigEndian()

virtual int64 juce::InputStream::readInt64BigEndian ( )

virtualinherited

Reads eight bytes from the stream as a big-endian 64-bit value.

If the next eight bytes are byte1 to byte8, this returns (byte8 | (byte7 << 8) | (byte6 << 16) | (byte5 << 24) | (byte4 << 32) | (byte3 << 40) | (byte2 << 48) | (byte1 << 56)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeInt64BigEndian, readInt64

readIntBigEndian()

virtual int juce::InputStream::readIntBigEndian ( )

virtualinherited

Reads four bytes from the stream as a big-endian 32-bit value.

If the next four bytes are byte1 to byte4, this returns (byte4 | (byte3 << 8) | (byte2 << 16) | (byte1 << 24)).

If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeIntBigEndian, readInt

readIntoMemoryBlock()

virtual size_t juce::InputStream::readIntoMemoryBlock ( MemoryBlock &  destBlock, ssize_t  maxNumBytesToRead = -1  )

virtualinherited

Reads from the stream and appends the data to a MemoryBlock.

Parameters

destBlock	the block to append the data onto
maxNumBytesToRead	if this is a positive value, it sets a limit to the number of bytes that will be read - if it's negative, data will be read until the stream is exhausted.

Returns

the number of bytes that were added to the memory block

readNextLine()

virtual String juce::InputStream::readNextLine ( )

virtualinherited

Reads a UTF-8 string from the stream, up to the next linefeed or carriage return.

This will read up to the next "\n" or "\r\n" or end-of-stream.

After this call, the stream's position will be left pointing to the next character following the line-feed, but the linefeeds aren't included in the string that is returned.

readShort()

virtual short juce::InputStream::readShort ( )

virtualinherited

Reads two bytes from the stream as a little-endian 16-bit value.

If the next two bytes read are byte1 and byte2, this returns (byte1 | (byte2 << 8)). If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeShort, readShortBigEndian

readShortBigEndian()

virtual short juce::InputStream::readShortBigEndian ( )

virtualinherited

Reads two bytes from the stream as a little-endian 16-bit value.

If the next two bytes read are byte1 and byte2, this returns (byte2 | (byte1 << 8)). If the stream is exhausted partway through reading the bytes, this will return zero.

See also

OutputStream::writeShortBigEndian, readShort

readString()

virtual String juce::InputStream::readString ( )

virtualinherited

Reads a zero-terminated UTF-8 string from the stream.

This will read characters from the stream until it hits a null character or end-of-stream.

See also

OutputStream::writeString, readEntireStreamAsString

Reimplemented in juce::BufferedInputStream.

setPosition()

bool juce::WebInputStream::setPosition ( int64  wantedPos )

overridevirtual

Tries to move the current read position of the stream.

The position is an absolute number of bytes from the stream's start.

For a WebInputStream, this method will fail if wantedPos is smaller than the current position. If wantedPos is greater than the current position, then calling setPosition() is the same as calling read(), i.e. the skipped data will still be downloaded, although skipped bytes will be discarded immediately.

Returns

true if the stream manages to reposition itself correctly

See also

getPosition

Implements juce::InputStream.

skipNextBytes()

virtual void juce::InputStream::skipNextBytes ( int64  numBytesToSkip )

virtualinherited

Reads and discards a number of bytes from the stream.

Some input streams might implement this more efficiently, but the base class will just keep reading data until the requisite number of bytes have been done. For large skips it may be quicker to call setPosition() with the required position.

Reimplemented in juce::MemoryInputStream.

withConnectionTimeout()

WebInputStream& juce::WebInputStream::withConnectionTimeout

(

int

timeoutInMs

)

Specify the connection time-out.

Returns a reference to itself so that several methods can be chained.

Parameters

timeoutInMs

the number of milliseconds to wait until the connection request is aborted.

withCustomRequestCommand()

WebInputStream& juce::WebInputStream::withCustomRequestCommand

(

const String &

customRequestCommand

)

Override the HTTP command that is sent.

Returns a reference to itself so that several methods can be chained.

Note that this command will not change the way parameters are sent. This must be specified in the constructor.

Parameters

customRequestCommand

this string is the custom HTTP request command such as POST or GET.

withExtraHeaders()

WebInputStream& juce::WebInputStream::withExtraHeaders

(

const String &

extraHeaders

)

Add extra headers to the HTTP request.

Returns a reference to itself so that several methods can be chained.

Parameters

extraHeaders

this string is appended onto the headers that are used for the request. It must therefore be a valid set of HTML header directives, separated by newlines.

withNumRedirectsToFollow()

WebInputStream& juce::WebInputStream::withNumRedirectsToFollow

(

int

numRedirects

)

Specify the number of redirects to be followed.

Returns a reference to itself so that several methods can be chained.

Parameters

numRedirects

specifies the number of redirects that will be followed before returning a response (ignored for Android which follows up to 5 redirects)

Friends And Related Function Documentation

Pimpl

friend class Pimpl

friend

Member Data Documentation

hasCalledConnect

bool juce::WebInputStream::hasCalledConnect = false

private

pimpl

std::unique_ptr<Pimpl> juce::WebInputStream::pimpl

private

---

The documentation for this class was generated from the following file:

• juce_WebInputStream.h