# Poco

# class URIStreamOpener

Library: Foundation
Package: URI
Header: Poco/URIStreamOpener.h

## Description

The URIStreamOpener class is used to create and open input streams for resourced identified by Uniform Resource Identifiers.

For every URI scheme used, a URIStreamFactory must be registered. A FileStreamFactory is automatically registered for file URIs.

## Member Summary

Member Functions: defaultOpener, open, openFile, openURI, registerStreamFactory, supportsScheme, unregisterStreamFactory

## Enumerations

### Anonymous

MAX_REDIRECTS = 10

## Constructors

### URIStreamOpener

URIStreamOpener();

Creates the URIStreamOpener and registers a FileStreamFactory for file URIs.

## Destructor

### ~URIStreamOpener

~URIStreamOpener();

Destroys the URIStreamOpener and deletes all registered URI stream factories.

## Member Functions

### defaultOpener

static URIStreamOpener & defaultOpener();

Returns a reference to the default URIStreamOpener.

### open

std::istream * open(
const URI & uri
) const;

Tries to create and open an input stream for the resource specified by the given uniform resource identifier.

If no URIStreamFactory has been registered for the URI's scheme, a UnknownURIScheme exception is thrown. If the stream cannot be opened for any reason, an IOException is thrown.

The given URI must be a valid one. This excludes file system paths.

Whoever calls the method is responsible for deleting the returned stream.

### open

std::istream * open(
const std::string & pathOrURI
) const;

Tries to create and open an input stream for the resource specified by the given path or uniform resource identifier.

If the stream cannot be opened for any reason, an Exception is thrown.

The method first tries to interpret the given pathOrURI as an URI. If this fails, the pathOrURI is treated as local filesystem path. If this also fails, an exception is thrown.

Whoever calls the method is responsible for deleting the returned stream.

### open

std::istream * open(
const std::string & basePathOrURI,
const std::string & pathOrURI
) const;

Tries to create and open an input stream for the resource specified by the given path or uniform resource identifier.

pathOrURI is resolved against basePathOrURI (see URI::resolve() and Path::resolve() for more information).

If the stream cannot be opened for any reason, an Exception is thrown.

Whoever calls the method is responsible for deleting the returned stream.

### registerStreamFactory

void registerStreamFactory(
const std::string & scheme,
URIStreamFactory * pFactory
);

Registers a URIStreamFactory for the given scheme. If another factory has already been registered for the scheme, an ExistsException is thrown.

The URIStreamOpener takes ownership of the factory and deletes it when it is no longer needed (in other words, when the URIStreamOpener is deleted).

### supportsScheme

bool supportsScheme(
const std::string & scheme
);

Returns true if and only if a URIStreamFactory for the given scheme has been registered.

### unregisterStreamFactory

void unregisterStreamFactory(
const std::string & scheme
);

Unregisters and deletes the URIStreamFactory for the given scheme.

Throws a NotFoundException if no URIStreamFactory has been registered for the given scheme.

### openFile

std::istream * openFile(
const Path & path
) const;

### openURI

std::istream * openURI(
const std::string & scheme,
const URI & uri
) const;