Package org.eclipse.e4.ui.css.swt.helpers

Class URI

java.lang.Object

org.eclipse.e4.ui.css.swt.helpers.URI

public final class URI
extends Object

A representation of a Uniform Resource Identifier (URI), as specified by RFC 2396, with certain enhancements. A URI instance can be created by specifying values for its components, or by providing a single URI string, which is parsed into its components. Static factory methods whose names begin with "create" are used for both forms of object creation. No public or protected constructors are provided; this class can not be subclassed.

Like String, URI is an immutable class; a URI instance offers several by-value methods that return a new URI object based on its current state. Most useful, a relative URI can be resolved against a base absolute URI -- the latter typically identifies the document in which the former appears. The inverse to this is deresolve, which answers the question, "what relative URI will resolve, against the given base, to this absolute URI?"

In the RFC, much attention is focused on a hierarchical naming system used widely to locate resources via common protocols such as HTTP, FTP, and Gopher, and to identify files on a local file system. Accordingly, most of this class's functionality is for handling such URIs, which can be identified via isHierarchical.

The primary enhancement beyond the RFC description is an optional device component. Instead of treating the device as just another segment in the path, it can be stored as a separate component (almost a sub-authority), with the root below it. For example, resolving /bar against file:///c:/foo would result in file:///c:/bar being returned. Also, you cannot take the parent of a device, so resolving .. against file:///c:/ would not yield file:///, as you might expect. This feature is useful when working with file-scheme URIs, as devices do not typically occur in protocol-based ones. A device-enabled URI is created by parsing a string with createURI; if the first segment of the path ends with the : character, it is stored (including the colon) as the device, instead. Alternately, either the no-path or the absolute-path form of createHierarchicalURI() can be used, in which a non-null device parameter can be specified.

The other enhancement provides support for the almost-hierarchical form used for files within archives, such as the JAR scheme, defined for the Java Platform in the documentation for JarURLConnection. By default, this support is enabled for absolute URIs with scheme equal to "jar", "zip", or "archive" (ignoring case), and is implemented by a hierarchical URI, whose authority includes the entire URI of the archive, up to and including the ! character. The URI of the archive must have no fragment. The whole archive URI must have no device and an absolute path. Special handling is supported for creating, validating, getting the path from, and displaying archive URIs. In all other operations, including resolving and deresolving, they are handled like any ordinary URI. The schemes that identify archive URIs can be changed from their default by setting the org.eclipse.emf.common.util.URI.archiveSchemes system property. Multiple schemes should be space separated, and the test of whether a URI's scheme matches is always case-insensitive.

This implementation does not impose all of the restrictions on character validity that are specified in the RFC. Static methods whose names begin with "valid" are used to test whether a given string is valid value for the various URI components. Presently, these tests place no restrictions beyond what would have been required in order for createURI to have parsed them correctly from a single URI string. If necessary in the future, these tests may be made more strict, to better conform to the RFC.

Another group of static methods, whose names begin with "encode", use percent escaping to encode any characters that are not permitted in the various URI components. Another static method is provided to decode encoded strings. An escaped character is represented as a percent symbol (%), followed by two hex digits that specify the character code. These encoding methods are more strict than the validation methods described above. They ensure validity according to the RFC, with one exception: non-ASCII characters.

The RFC allows only characters that can be mapped to 7-bit US-ASCII representations. Non-ASCII, single-byte characters can be used only via percent escaping, as described above. This implementation uses Java's Unicode char and String representations, and makes no attempt to encode characters 0xA0 and above. Characters in the range 0x80-0x9F are still escaped. In this respect, EMF's notion of a URI is actually more like an IRI (Internationalized Resource Identifier), for which an RFC is now in draft form.

Finally, note the difference between a null parameter to the static factory methods and an empty string. The former signifies the absence of a given URI component, while the latter simply makes the component blank. This can have a significant effect when resolving. For example, consider the following two URIs: /bar (with no authority) and ///bar (with a blank authority). Imagine resolving them against a base with an authority, such as http://www.eclipse.org/. The former case will yield http://www.eclipse.org/bar, as the base authority will be preserved. In the latter case, the empty authority will override the base authority, resulting in http:///bar!

Field Summary

Fields

Modifier and Type	Field	Description
static final int	FRAGMENT_FIRST_SEPARATOR	When specified as the last argument to createURI, indicates that the first # character should be taken as the fragment separator, and any others should be encoded.
static final int	FRAGMENT_LAST_SEPARATOR	When specified as the last argument to createURI, indicates that the last # character should be taken as the fragment separator, and any others should be encoded.
static final int	FRAGMENT_NONE	When specified as the last argument to createURI, indicates that there is no fragment, so any # characters should be encoded.

Method Summary

Modifier and Type	Method	Description
URI	appendFileExtension(String fileExtension)	Returns the URI formed by appending a period (".") followed by the specified file extension to the last path segment of this URI, if it is hierarchical with a non-empty path ending in a non-empty segment; otherwise, this URI is returned unchanged.
URI	appendFragment(String fragment)	Returns the URI formed from this URI and the given fragment.
URI	appendQuery(String query)	Returns the URI formed from this URI and the given query.
URI	appendSegment(String segment)	Returns the URI formed by appending the specified segment on to the end of the path of this URI, if hierarchical; this URI unchanged, otherwise.
URI	appendSegments(String[] segments)	Returns the URI formed by appending the specified segments on to the end of the path of this URI, if hierarchical; this URI unchanged, otherwise.
String	authority()	If this is a hierarchical URI with an authority component, returns it; null otherwise.
static URI	createDeviceURI(String uri)	Deprecated. Use createURI, which now has explicit device support enabled.
static URI	createFileURI(String pathName)	Static factory method based on parsing a File path string.
static URI	createGenericURI(String scheme, String opaquePart, String fragment)	Static factory method for a generic, non-hierarchical URI.
static URI	createHierarchicalURI(String[] segments, String query, String fragment)	Static factory method for a relative hierarchical URI with relative path.
static URI	createHierarchicalURI(String scheme, String authority, String device, String[] segments, String query, String fragment)	Static factory method for a hierarchical URI with absolute path.
static URI	createHierarchicalURI(String scheme, String authority, String device, String query, String fragment)	Static factory method for a hierarchical URI with no path.
static URI	createPlatformPluginURI(String pathName, boolean encode)	Static factory method based on parsing a plug-in-based path string, with an option to encode the created URI.
static URI	createPlatformResourceURI(String pathName)	Deprecated. Use createPlatformResourceURI(String, boolean) instead.
static URI	createPlatformResourceURI(String pathName, boolean encode)	Static factory method based on parsing a workspace-relative path string, with an option to encode the created URI.
static URI	createURI(String uri)	Static factory method based on parsing a URI string, with explicit device support and handling for archive URIs enabled.
static URI	createURI(String uri, boolean ignoreEscaped)	Static factory method that encodes and parses the given URI string.
static URI	createURI(String uri, boolean ignoreEscaped, int fragmentLocationStyle)	Static factory method that encodes and parses the given URI string.
static URI	createURIWithCache(String uri)	Deprecated. Please use createURI instead.
static String	decode(String value)	Decodes the given string by interpreting three-digit escape sequences as the bytes of a UTF-8 encoded character and replacing them with the characters they represent.
URI	deresolve(URI base)	Finds the shortest relative or, if necessary, the absolute URI that, when resolved against the given base absolute hierarchical URI using resolve, will yield this absolute URI.
URI	deresolve(URI base, boolean preserveRootParents, boolean anyRelPath, boolean shorterRelPath)	Finds an absolute URI that, when resolved against the given base absolute hierarchical URI using resolve, will yield this absolute URI.
String	device()	If this is a hierarchical URI with a device component, returns it; null otherwise.
String	devicePath()	If this is a hierarchical URI with a path, returns a string representation of the path, including the authority and the device component; null otherwise.
static String	encodeAuthority(String value, boolean ignoreEscaped)	Encodes a string so as to produce a valid authority, as defined by the RFC.
static String	encodeFragment(String value, boolean ignoreEscaped)	Encodes a string so as to produce a valid fragment, as defined by the RFC.
static String	encodeOpaquePart(String value, boolean ignoreEscaped)	Encodes a string so as to produce a valid opaque part value, as defined by the RFC.
static String	encodeQuery(String value, boolean ignoreEscaped)	Encodes a string so as to produce a valid query, as defined by the RFC.
static String	encodeSegment(String value, boolean ignoreEscaped)	Encodes a string so as to produce a valid segment, as defined by the RFC.
boolean	equals(Object object)	Returns true if object is an instance of URI equal to this one; false otherwise.
String	fileExtension()	If this is a hierarchical URI whose path includes a file extension, that file extension is returned; null otherwise.
String	fragment()	If this URI has a fragment component, returns it; null otherwise.
boolean	hasAbsolutePath()	Returns true if this is a hierarchical URI with an absolute path, or false if it is non-hierarchical, has no path, or has a relative path.
boolean	hasAuthority()	Returns true if this is a hierarchical URI with an authority component; false otherwise.
boolean	hasDevice()	Returns true if this is a hierarchical URI with a device component; false otherwise.
boolean	hasEmptyPath()	Returns true if this is a hierarchical URI with an empty relative path; false otherwise.
boolean	hasFragment()	Returns true if this URI has a fragment component; false otherwise.
int	hashCode()	Returns the hash code.
boolean	hasOpaquePart()	Returns true if this is a non-hierarchical URI with an opaque part component; false otherwise.
boolean	hasPath()	Returns true if this is a hierarchical URI with an absolute or relative path; false otherwise.
boolean	hasQuery()	Returns true if this is a hierarchical URI with a query component; false otherwise.
boolean	hasRelativePath()	Returns true if this is a hierarchical URI with a relative path, or false if it is non-hierarchical, has no path, or has an absolute path.
boolean	hasTrailingPathSeparator()	Returns true if this is a hierarchical URI that has a path that ends with a trailing separator; false otherwise.
String	host()	If this is a hierarchical URI with an authority component that has a host portion, returns it; null otherwise.
boolean	isArchive()	Returns true if this is an archive URI.
static boolean	isArchiveScheme(String value)	Returns true if the specified value would be valid as the scheme of an archive URI; false otherwise.
boolean	isCurrentDocumentReference()	Returns true if this is a current document reference; that is, if it is a relative hierarchical URI with no authority, device or query components, and no path segments; false is returned otherwise.
boolean	isEmpty()	Returns true if this is a current document reference with no fragment component; false otherwise.
boolean	isFile()	Returns true if this is a hierarchical URI that may refer directly to a locally accessible file.
boolean	isHierarchical()	Returns true if this a a hierarchical URI, or false if it is of the generic form.
boolean	isPlatform()	Returns true if this is a platform URI, that is, an absolute, hierarchical URI, with "platform" scheme, no authority, and at least two segments; false is returned otherwise.
boolean	isPlatformPlugin()	Returns true if this is a platform plug-in URI, that is, a platform URI whose first segment is "plugin"; false is returned otherwise.
boolean	isPlatformResource()	Returns true if this is a platform resource URI, that is, a platform URI whose first segment is "resource"; false is returned otherwise.
boolean	isPrefix()	Returns true if this is a hierarchical URI that ends in a slash; that is, it has a trailing path separator or is the root absolute path, and has no query and no fragment; false is returned otherwise.
boolean	isRelative()	Returns true if this is a relative URI, or false if it is an absolute URI.
String	lastSegment()	Returns the last segment in the segment array, or null.
String	opaquePart()	If this is a non-hierarchical URI, returns the opaque part component; null otherwise.
String	path()	If this is a hierarchical URI with a path, returns a string representation of the path; null otherwise.
String	port()	If this is a hierarchical URI with an authority component that has a port portion, returns it; null otherwise.
String	query()	If this is a hierarchical URI with a query component, returns it; null otherwise.
URI	replacePrefix(URI oldPrefix, URI newPrefix)	If this is a hierarchical URI reference and oldPrefix is a prefix of it, this returns the URI formed by replacing it by newPrefix; null otherwise.
URI	resolve(URI base)	Resolves this URI reference against a base absolute hierarchical URI, returning the resulting absolute URI.
URI	resolve(URI base, boolean preserveRootParents)	Resolves this URI reference against a base absolute hierarchical URI, returning the resulting absolute URI.
String	scheme()	If this is an absolute URI, returns the scheme component; null otherwise.
String	segment(int i)	Provides fast, indexed access to individual segments in the path segment array.
int	segmentCount()	Returns the number of elements in the segment array that would be returned by segments.
String[]	segments()	If this is a hierarchical URI with a path, returns an array containing the segments of the path; an empty array otherwise.
List<String>	segmentsList()	Returns an unmodifiable list containing the same segments as the array returned by segments.
String	toFileString()	If this URI may refer directly to a locally accessible file, as determined by isFile, decodes and formats the URI as a pathname to that file; returns null otherwise.
String	toPlatformString(boolean decode)	If this is a platform URI, as determined by isPlatform(), returns the workspace-relative or plug-in-based path to the resource, optionally decoding the segments in the process.
String	toString()	Returns the string representation of this URI.
URI	trimFileExtension()	If this URI has a non-null fileExtension, returns the URI formed by removing it; this URI unchanged, otherwise.
URI	trimFragment()	If this URI has a non-null fragment, returns the URI formed by removing it; this URI unchanged, otherwise.
URI	trimQuery()	If this URI has a non-null query, returns the URI formed by removing it; this URI unchanged, otherwise.
URI	trimSegments(int i)	Returns the URI formed by trimming the specified number of segments (including empty segments, such as one representing a trailing separator) from the end of the path of this URI, if hierarchical; otherwise, this URI is returned unchanged.
String	userInfo()	If this is a hierarchical URI with an authority component that has a user info portion, returns it; null otherwise.
static boolean	validArchiveAuthority(String value)	Returns true if the specified value would be valid as the authority component of an archive URI; false otherwise.
static boolean	validAuthority(String value)	Returns true if the specified value would be valid as the authority component of a URI; false otherwise.
static boolean	validDevice(String value)	Returns true if the specified value would be valid as the device component of a URI; false otherwise.
static boolean	validFragment(String value)	Returns true if the specified value would be valid as the fragment component of a URI; false otherwise.
static boolean	validJarAuthority(String value)	Deprecated. As of EMF 2.0, replaced by validArchiveAuthority.
static boolean	validOpaquePart(String value)	Returns true if the specified value would be valid as the opaque part component of a URI; false otherwise.
static boolean	validQuery(String value)	Returns true if the specified value would be valid as the query component of a URI; false otherwise.
static boolean	validScheme(String value)	Returns true if the specified value would be valid as the scheme component of a URI; false otherwise.
static boolean	validSegment(String value)	Returns true if the specified value would be a valid path segment of a URI; false otherwise.
static boolean	validSegments(String[] value)	Returns true if the specified value would be a valid path segment array of a URI; false otherwise.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details

FRAGMENT_NONE

public static final int FRAGMENT_NONE

When specified as the last argument to createURI, indicates that there is no fragment, so any # characters should be encoded.

See Also:

• createURI(String, boolean, int)
• Constant Field Values

FRAGMENT_FIRST_SEPARATOR

public static final int FRAGMENT_FIRST_SEPARATOR

When specified as the last argument to createURI, indicates that the first # character should be taken as the fragment separator, and any others should be encoded.

See Also:

• createURI(String, boolean, int)
• Constant Field Values

FRAGMENT_LAST_SEPARATOR

public static final int FRAGMENT_LAST_SEPARATOR

When specified as the last argument to createURI, indicates that the last # character should be taken as the fragment separator, and any others should be encoded.

See Also:

• createURI(String, boolean, int)
• Constant Field Values

Method Details

createGenericURI

public static URI createGenericURI(String scheme,
 String opaquePart,
 String fragment)

Static factory method for a generic, non-hierarchical URI. There is no concept of a relative non-hierarchical URI; such an object cannot be created.

Throws:

IllegalArgumentException - if scheme is null, if scheme is an archive URI scheme, or if scheme, opaquePart, or fragment is not valid according to validScheme, validOpaquePart, or validFragment, respectively.

createHierarchicalURI

public static URI createHierarchicalURI(String scheme,
 String authority,
 String device,
 String query,
 String fragment)

Static factory method for a hierarchical URI with no path. The URI will be relative if scheme is non-null, and absolute otherwise. An absolute URI with no path requires a non-null authority and/or device.

Throws:

IllegalArgumentException - if scheme is non-null while authority and device are null, if scheme is an archive URI scheme, or if scheme, authority, device, query, or fragment is not valid according to validSheme, validAuthority, validDevice, validQuery, or validFragment, respectively.

createHierarchicalURI

public static URI createHierarchicalURI(String scheme,
 String authority,
 String device,
 String[] segments,
 String query,
 String fragment)

Static factory method for a hierarchical URI with absolute path. The URI will be relative if scheme is non-null, and absolute otherwise.

Parameters:

segments - an array of non-null strings, each representing one segment of the path. As an absolute path, it is automatically preceded by a / separator. If desired, a trailing separator should be represented by an empty-string segment as the last element of the array.

Throws:

IllegalArgumentException - if scheme is an archive URI scheme and device is non-null, or if scheme, authority, device, segments, query, or fragment is not valid according to validScheme, validAuthority or validArchiveAuthority, validDevice, validSegments, validQuery, or validFragment, as appropriate.

createHierarchicalURI

public static URI createHierarchicalURI(String[] segments,
 String query,
 String fragment)

Static factory method for a relative hierarchical URI with relative path.

Parameters:

segments - an array of non-null strings, each representing one segment of the path. A trailing separator is represented by an empty-string segment at the end of the array.

Throws:

IllegalArgumentException - if segments, query, or fragment is not valid according to validSegments, validQuery, or validFragment, respectively.

createURI

public static URI createURI(String uri)

Static factory method based on parsing a URI string, with explicit device support and handling for archive URIs enabled. The specified string is parsed as described in RFC 2396, and an appropriate URI is created and returned. Note that validity testing is not as strict as in the RFC; essentially, only separator characters are considered. This method also does not perform encoding of invalid characters, so it should only be used when the URI string is known to have already been encoded, so as to avoid double encoding.

Throws:

IllegalArgumentException - if any component parsed from uri is not valid according to validScheme, validOpaquePart, validAuthority, validArchiveAuthority, validDevice, validSegments, validQuery, or validFragment, as appropriate.

createURI

public static URI createURI(String uri,
 boolean ignoreEscaped)

Static factory method that encodes and parses the given URI string. Appropriate encoding is performed for each component of the URI. If more than one # is in the string, the last one is assumed to be the fragment's separator, and any others are encoded. This method is the simplest way to safely parse an arbitrary URI string.

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. This capability is provided to allow partially encoded URIs to be "fixed", while avoiding adding double encoding; however, it is usual just to specify false to perform ordinary encoding.

Throws:

IllegalArgumentException - if any component parsed from uri is not valid according to validScheme, validOpaquePart, validAuthority, validArchiveAuthority, validDevice, validSegments, validQuery, or validFragment, as appropriate.

createURI

public static URI createURI(String uri,
 boolean ignoreEscaped,
 int fragmentLocationStyle)

Static factory method that encodes and parses the given URI string. Appropriate encoding is performed for each component of the URI. Control is provided over which, if any, # should be taken as the fragment separator and which should be encoded. This method is the preferred way to safely parse an arbitrary URI string that is known to contain # characters in the fragment or to have no fragment at all.

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. This capability is provided to allow partially encoded URIs to be "fixed", while avoiding adding double encoding; however, it is usual just to specify false to perform ordinary encoding.

fragmentLocationStyle - one of FRAGMENT_NONE, FRAGMENT_FIRST_SEPARATOR, or FRAGMENT_LAST_SEPARATOR, indicating which, if any, of the # characters should be considered the fragment separator. Any others will be encoded.

Throws:

IllegalArgumentException - if any component parsed from uri is not valid according to validScheme, validOpaquePart, validAuthority, validArchiveAuthority, validDevice, validSegments, validQuery, or validFragment, as appropriate.

createDeviceURI

@Deprecated
public static URI createDeviceURI(String uri)

Deprecated.

Use createURI, which now has explicit device support enabled. The two methods now operate identically.

Static factory method based on parsing a URI string, with explicit device support enabled. Note that validity testing is not a strict as in the RFC; essentially, only separator characters are considered. So, for example, non-Latin alphabet characters appearing in the scheme would not be considered an error.

Throws:

IllegalArgumentException - if any component parsed from uri is not valid according to validScheme, validOpaquePart, validAuthority, validArchiveAuthority, validDevice, validSegments, validQuery, or validFragment, as appropriate.

createURIWithCache

@Deprecated
public static URI createURIWithCache(String uri)

Deprecated.

Please use createURI instead.

This method was included in the public API by mistake.

createFileURI

public static URI createFileURI(String pathName)

Static factory method based on parsing a File path string. The pathName is converted into an appropriate form, as follows: platform specific path separators are converted to /; the path is encoded; and a "file" scheme and, if missing, a leading /, are added to an absolute path. The result is then parsed using createURI.

The encoding step escapes all spaces, # characters, and other characters disallowed in URIs, as well as ?, which would delimit a path from a query. Decoding is automatically performed by toFileString, and can be applied to the values returned by other accessors by via the static decode method.

A relative path with a specified device (something like C:myfile.txt) cannot be expressed as a valid URI.

Throws:

IllegalArgumentException - if pathName specifies a device and a relative path, or if any component of the path is not valid according to validAuthority, validDevice, or validSegments, validQuery, or validFragment.

createPlatformResourceURI

@Deprecated
public static URI createPlatformResourceURI(String pathName)

Deprecated.

Use createPlatformResourceURI(String, boolean) instead.

Static factory method based on parsing a workspace-relative path string.

The pathName must be of the form:

   /project-name/path

Platform-specific path separators will be converted to slashes. If not included, the leading path separator will be added. The result will be of this form, which is parsed using createURI:

   platform:/resource/project-name/path

This scheme supports relocatable projects in Eclipse and in stand-alone EMF.

Path encoding is performed only if the org.eclipse.emf.common.util.URI.encodePlatformResourceURIs system property is set to "true". Decoding can be performed with the static decode method.

Throws:

IllegalArgumentException - if any component parsed from the path is not valid according to validDevice, validSegments, validQuery, or validFragment.

See Also:

• Platform.resolve(java.net.URL)
• createPlatformResourceURI(String, boolean)

createPlatformResourceURI

public static URI createPlatformResourceURI(String pathName,
 boolean encode)

Static factory method based on parsing a workspace-relative path string, with an option to encode the created URI.

The pathName must be of the form:

   /project-name/path

Platform-specific path separators will be converted to slashes. If not included, the leading path separator will be added. The result will be of this form, which is parsed using createURI:

   platform:/resource/project-name/path

This scheme supports relocatable projects in Eclipse and in stand-alone EMF.

Depending on the encode argument, the path may be automatically encoded to escape all spaces, # characters, and other characters disallowed in URIs, as well as ?, which would delimit a path from a query. Decoding can be performed with the static decode method. It is strongly recommended to specify true to enable encoding, unless the path string has already been encoded.

Throws:

IllegalArgumentException - if any component parsed from the path is not valid according to validDevice, validSegments, validQuery, or validFragment.

See Also:

• Platform.resolve(java.net.URL)

createPlatformPluginURI

public static URI createPlatformPluginURI(String pathName,
 boolean encode)

Static factory method based on parsing a plug-in-based path string, with an option to encode the created URI.

The pathName must be of the form:

   /plugin-id/path

Platform-specific path separators will be converted to slashes. If not included, the leading path separator will be added. The result will be of this form, which is parsed using createURI:

   platform:/plugin/plugin-id/path

This scheme supports relocatable plug-in content in Eclipse.

Depending on the encode argument, the path may be automatically encoded to escape all spaces, # characters, and other characters disallowed in URIs, as well as ?, which would delimit a path from a query. Decoding can be performed with the static decode method. It is strongly recommended to specify true to enable encoding, unless the path string has already been encoded.

Throws:

IllegalArgumentException - if any component parsed from the path is not valid according to validDevice, validSegments, validQuery, or validFragment.

Since:

org.eclipse.emf.common 2.3

See Also:

• Platform.resolve(java.net.URL)

validScheme

public static boolean validScheme(String value)

Returns true if the specified value would be valid as the scheme component of a URI; false otherwise.

A valid scheme may be null or contain any characters except for the following: : / ? #

validOpaquePart

public static boolean validOpaquePart(String value)

Returns true if the specified value would be valid as the opaque part component of a URI; false otherwise.

A valid opaque part must be non-null, non-empty, and not contain the # character. In addition, its first character must not be /

validAuthority

public static boolean validAuthority(String value)

Returns true if the specified value would be valid as the authority component of a URI; false otherwise.

A valid authority may be null or contain any characters except for the following: / ? #

validArchiveAuthority

public static boolean validArchiveAuthority(String value)

Returns true if the specified value would be valid as the authority component of an archive URI; false otherwise.

To be valid, the authority, itself, must be a URI with no fragment, followed by the character !.

validJarAuthority

@Deprecated
public static boolean validJarAuthority(String value)

Deprecated.

As of EMF 2.0, replaced by validArchiveAuthority.

Tests whether the specified value would be valid as the authority component of an archive URI. This method has been replaced by validArchiveAuthority since the same form of URI is now supported for schemes other than "jar". This now simply calls that method.

validDevice

public static boolean validDevice(String value)

Returns true if the specified value would be valid as the device component of a URI; false otherwise.

A valid device may be null or non-empty, containing any characters except for the following: / ? # In addition, its last character must be :

validSegment

public static boolean validSegment(String value)

Returns true if the specified value would be a valid path segment of a URI; false otherwise.

A valid path segment must be non-null and not contain any of the following characters: / ? #

validSegments

public static boolean validSegments(String[] value)

Returns true if the specified value would be a valid path segment array of a URI; false otherwise.

A valid path segment array must be non-null and contain only path segments that are valid according to validSegment.

validQuery

public static boolean validQuery(String value)

Returns true if the specified value would be valid as the query component of a URI; false otherwise.

A valid query may be null or contain any characters except for #

validFragment

public static boolean validFragment(String value)

Returns true if the specified value would be valid as the fragment component of a URI; false otherwise.

A fragment is taken to be unconditionally valid.

isRelative

public boolean isRelative()

Returns true if this is a relative URI, or false if it is an absolute URI.

isHierarchical

public boolean isHierarchical()

Returns true if this a a hierarchical URI, or false if it is of the generic form.

hasAuthority

public boolean hasAuthority()

Returns true if this is a hierarchical URI with an authority component; false otherwise.

hasOpaquePart

public boolean hasOpaquePart()

Returns true if this is a non-hierarchical URI with an opaque part component; false otherwise.

hasDevice

public boolean hasDevice()

Returns true if this is a hierarchical URI with a device component; false otherwise.

hasPath

public boolean hasPath()

Returns true if this is a hierarchical URI with an absolute or relative path; false otherwise.

hasAbsolutePath

public boolean hasAbsolutePath()

Returns true if this is a hierarchical URI with an absolute path, or false if it is non-hierarchical, has no path, or has a relative path.

hasRelativePath

public boolean hasRelativePath()

Returns true if this is a hierarchical URI with a relative path, or false if it is non-hierarchical, has no path, or has an absolute path.

hasEmptyPath

public boolean hasEmptyPath()

Returns true if this is a hierarchical URI with an empty relative path; false otherwise.

Note that !hasEmpty() does not imply that this URI has any path segments; however, hasRelativePath && !hasEmptyPath() does.

hasQuery

public boolean hasQuery()

Returns true if this is a hierarchical URI with a query component; false otherwise.

hasFragment

public boolean hasFragment()

Returns true if this URI has a fragment component; false otherwise.

isCurrentDocumentReference

public boolean isCurrentDocumentReference()

Returns true if this is a current document reference; that is, if it is a relative hierarchical URI with no authority, device or query components, and no path segments; false is returned otherwise.

isEmpty

public boolean isEmpty()

Returns true if this is a current document reference with no fragment component; false otherwise.

See Also:

• isCurrentDocumentReference()

isFile

public boolean isFile()

Returns true if this is a hierarchical URI that may refer directly to a locally accessible file. This is considered to be the case for a file-scheme absolute URI, or for a relative URI with no query; false is returned otherwise.

isPlatform

public boolean isPlatform()

Returns true if this is a platform URI, that is, an absolute, hierarchical URI, with "platform" scheme, no authority, and at least two segments; false is returned otherwise.

Since:

org.eclipse.emf.common 2.3

isPlatformResource

public boolean isPlatformResource()

Returns true if this is a platform resource URI, that is, a platform URI whose first segment is "resource"; false is returned otherwise.

Since:

org.eclipse.emf.common 2.3

See Also:

• isPlatform()

isPlatformPlugin

public boolean isPlatformPlugin()

Returns true if this is a platform plug-in URI, that is, a platform URI whose first segment is "plugin"; false is returned otherwise.

Since:

org.eclipse.emf.common 2.3

See Also:

• isPlatform()

isArchive

public boolean isArchive()

Returns true if this is an archive URI. If so, it is also hierarchical, with an authority (consisting of an absolute URI followed by "!"), no device, and an absolute path.

isArchiveScheme

public static boolean isArchiveScheme(String value)

Returns true if the specified value would be valid as the scheme of an archive URI; false otherwise.

hashCode

public int hashCode()

Returns the hash code.

Overrides:

hashCode in class Object

equals

public boolean equals(Object object)

Returns true if object is an instance of URI equal to this one; false otherwise.

Equality is determined strictly by comparing components, not by attempting to interpret what resource is being identified. The comparison of schemes is case-insensitive.

Overrides:

equals in class Object

scheme

public String scheme()

If this is an absolute URI, returns the scheme component; null otherwise.

opaquePart

public String opaquePart()

If this is a non-hierarchical URI, returns the opaque part component; null otherwise.

authority

public String authority()

If this is a hierarchical URI with an authority component, returns it; null otherwise.

userInfo

public String userInfo()

If this is a hierarchical URI with an authority component that has a user info portion, returns it; null otherwise.

host

public String host()

If this is a hierarchical URI with an authority component that has a host portion, returns it; null otherwise.

port

public String port()

If this is a hierarchical URI with an authority component that has a port portion, returns it; null otherwise.

device

public String device()

If this is a hierarchical URI with a device component, returns it; null otherwise.

segments

public String[] segments()

If this is a hierarchical URI with a path, returns an array containing the segments of the path; an empty array otherwise. The leading separator in an absolute path is not represented in this array, but a trailing separator is represented by an empty-string segment as the final element.

segmentsList

public List<String> segmentsList()

Returns an unmodifiable list containing the same segments as the array returned by segments.

segmentCount

public int segmentCount()

Returns the number of elements in the segment array that would be returned by segments.

segment

public String segment(int i)

Provides fast, indexed access to individual segments in the path segment array.

Throws:

IndexOutOfBoundsException - if i < 0 or i >= segmentCount().

lastSegment

public String lastSegment()

Returns the last segment in the segment array, or null.

path

public String path()

If this is a hierarchical URI with a path, returns a string representation of the path; null otherwise. The path consists of a leading segment separator character (a slash), if the path is absolute, followed by the slash-separated path segments. If this URI has a separate device component, it is not included in the path.

devicePath

public String devicePath()

If this is a hierarchical URI with a path, returns a string representation of the path, including the authority and the device component; null otherwise.

If there is no authority, the format of this string is:

   device/pathSegment1/pathSegment2...

If there is an authority, it is:

   //authority/device/pathSegment1/pathSegment2...

For an archive URI, it's just:

   authority/pathSegment1/pathSegment2...

query

public String query()

If this is a hierarchical URI with a query component, returns it; null otherwise.

appendQuery

public URI appendQuery(String query)

Returns the URI formed from this URI and the given query.

Throws:

IllegalArgumentException - if query is not a valid query (portion) according to validQuery.

trimQuery

public URI trimQuery()

If this URI has a non-null query, returns the URI formed by removing it; this URI unchanged, otherwise.

fragment

public String fragment()

If this URI has a fragment component, returns it; null otherwise.

appendFragment

public URI appendFragment(String fragment)

Returns the URI formed from this URI and the given fragment.

Throws:

IllegalArgumentException - if fragment is not a valid fragment (portion) according to validFragment.

trimFragment

public URI trimFragment()

If this URI has a non-null fragment, returns the URI formed by removing it; this URI unchanged, otherwise.

resolve

public URI resolve(URI base)

Resolves this URI reference against a base absolute hierarchical URI, returning the resulting absolute URI. If already absolute, the URI itself is returned. URI resolution is described in detail in section 5.2 of RFC 2396, "Resolving Relative References to Absolute Form."

During resolution, empty segments, self references ("."), and parent references ("..") are interpreted, so that they can be removed from the path. Step 6(g) gives a choice of how to handle the case where parent references point to a path above the root: the offending segments can be preserved or discarded. This method preserves them. To have them discarded, please use the two-parameter form of resolve.

Throws:

IllegalArgumentException - if base is non-hierarchical or is relative.

resolve

public URI resolve(URI base,
 boolean preserveRootParents)

Resolves this URI reference against a base absolute hierarchical URI, returning the resulting absolute URI. If already absolute, the URI itself is returned. URI resolution is described in detail in section 5.2 of RFC 2396, "Resolving Relative References to Absolute Form."

During resolution, empty segments, self references ("."), and parent references ("..") are interpreted, so that they can be removed from the path. Step 6(g) gives a choice of how to handle the case where parent references point to a path above the root: the offending segments can be preserved or discarded. This method can do either.

Parameters:

preserveRootParents - true if segments referring to the parent of the root path are to be preserved; false if they are to be discarded.

Throws:

IllegalArgumentException - if base is non-hierarchical or is relative.

deresolve

public URI deresolve(URI base)

Finds the shortest relative or, if necessary, the absolute URI that, when resolved against the given base absolute hierarchical URI using resolve, will yield this absolute URI. If base is non-hierarchical or is relative, or this is non-hierarchical or is relative, this will be returned.

deresolve

public URI deresolve(URI base,
 boolean preserveRootParents,
 boolean anyRelPath,
 boolean shorterRelPath)

Finds an absolute URI that, when resolved against the given base absolute hierarchical URI using resolve, will yield this absolute URI. If base is non-hierarchical or is relative, or this is non-hierarchical or is relative, this will be returned.

Parameters:

preserveRootParents - the boolean argument to resolve(URI, boolean) for which the returned URI should resolve to this URI.

anyRelPath - if true, the returned URI's path (if any) will be relative, if possible. If false, the form of the result's path will depend upon the next parameter.

shorterRelPath - if anyRelPath is false and this parameter is true, the returned URI's path (if any) will be relative, if one can be found that is no longer (by number of segments) than the absolute path. If both anyRelPath and this parameter are false, it will be absolute.

toString

public String toString()

Returns the string representation of this URI. For a generic, non-hierarchical URI, this looks like:

   scheme:opaquePart#fragment

For a hierarchical URI, it looks like:

   scheme://authority/device/pathSegment1/pathSegment2...?query#fragment

For an archive URI, it's just:

   scheme:authority/pathSegment1/pathSegment2...?query#fragment

Of course, absent components and their separators will be omitted.

Overrides:

toString in class Object

toFileString

public String toFileString()

If this URI may refer directly to a locally accessible file, as determined by isFile, decodes and formats the URI as a pathname to that file; returns null otherwise.

If there is no authority, the format of this string is:

   device/pathSegment1/pathSegment2...

If there is an authority, it is:

   //authority/device/pathSegment1/pathSegment2...

However, the character used as a separator is system-dependent and obtained from File.separatorChar.

toPlatformString

public String toPlatformString(boolean decode)

If this is a platform URI, as determined by isPlatform(), returns the workspace-relative or plug-in-based path to the resource, optionally decoding the segments in the process.

Since:

org.eclipse.emf.common 2.3

See Also:

• createPlatformResourceURI(String, boolean)
• createPlatformPluginURI(java.lang.String, boolean)

appendSegment

public URI appendSegment(String segment)

Returns the URI formed by appending the specified segment on to the end of the path of this URI, if hierarchical; this URI unchanged, otherwise. If this URI has an authority and/or device, but no path, the segment becomes the first under the root in an absolute path.

Throws:

IllegalArgumentException - if segment is not a valid segment according to validSegment(java.lang.String).

appendSegments

public URI appendSegments(String[] segments)

Returns the URI formed by appending the specified segments on to the end of the path of this URI, if hierarchical; this URI unchanged, otherwise. If this URI has an authority and/or device, but no path, the segments are made to form an absolute path.

Parameters:

segments - an array of non-null strings, each representing one segment of the path. If desired, a trailing separator should be represented by an empty-string segment as the last element of the array.

Throws:

IllegalArgumentException - if segments is not a valid segment array according to validSegments(java.lang.String[]).

trimSegments

public URI trimSegments(int i)

Returns the URI formed by trimming the specified number of segments (including empty segments, such as one representing a trailing separator) from the end of the path of this URI, if hierarchical; otherwise, this URI is returned unchanged.

Note that if all segments are trimmed from an absolute path, the root absolute path remains.

Parameters:

i - the number of segments to be trimmed in the returned URI. If less than 1, this URI is returned unchanged; if equal to or greater than the number of segments in this URI's path, all segments are trimmed.

hasTrailingPathSeparator

public boolean hasTrailingPathSeparator()

Returns true if this is a hierarchical URI that has a path that ends with a trailing separator; false otherwise.

A trailing separator is represented as an empty segment as the last segment in the path; note that this definition does not include the lone separator in the root absolute path.

fileExtension

public String fileExtension()

If this is a hierarchical URI whose path includes a file extension, that file extension is returned; null otherwise. We define a file extension as any string following the last period (".") in the final path segment. If there is no path, the path ends in a trailing separator, or the final segment contains no period, then we consider there to be no file extension. If the final segment ends in a period, then the file extension is an empty string.

appendFileExtension

public URI appendFileExtension(String fileExtension)

Returns the URI formed by appending a period (".") followed by the specified file extension to the last path segment of this URI, if it is hierarchical with a non-empty path ending in a non-empty segment; otherwise, this URI is returned unchanged.

The extension is appended regardless of whether the segment already contains an extension.

Throws:

IllegalArgumentException - if fileExtension is not a valid segment (portion) according to validSegment(java.lang.String).

trimFileExtension

public URI trimFileExtension()

If this URI has a non-null fileExtension, returns the URI formed by removing it; this URI unchanged, otherwise.

isPrefix

public boolean isPrefix()

Returns true if this is a hierarchical URI that ends in a slash; that is, it has a trailing path separator or is the root absolute path, and has no query and no fragment; false is returned otherwise.

replacePrefix

public URI replacePrefix(URI oldPrefix,
 URI newPrefix)

If this is a hierarchical URI reference and oldPrefix is a prefix of it, this returns the URI formed by replacing it by newPrefix; null otherwise.

In order to be a prefix, the oldPrefix's isPrefix must return true, and it must match this URI's scheme, authority, and device. Also, the paths must match, up to prefix's end.

Throws:

IllegalArgumentException - if either oldPrefix or newPrefix is not a prefix URI according to isPrefix().

encodeOpaquePart

public static String encodeOpaquePart(String value,
 boolean ignoreEscaped)

Encodes a string so as to produce a valid opaque part value, as defined by the RFC. All excluded characters, such as space and #, are escaped, as is / if it is the first character.

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. Note that if a % is not followed by 2 hex digits, it will always be escaped.

encodeAuthority

public static String encodeAuthority(String value,
 boolean ignoreEscaped)

Encodes a string so as to produce a valid authority, as defined by the RFC. All excluded characters, such as space and #, are escaped, as are / and ?

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. Note that if a % is not followed by 2 hex digits, it will always be escaped.

encodeSegment

public static String encodeSegment(String value,
 boolean ignoreEscaped)

Encodes a string so as to produce a valid segment, as defined by the RFC. All excluded characters, such as space and #, are escaped, as are / and ?

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. Note that if a % is not followed by 2 hex digits, it will always be escaped.

encodeQuery

public static String encodeQuery(String value,
 boolean ignoreEscaped)

Encodes a string so as to produce a valid query, as defined by the RFC. Only excluded characters, such as space and #, are escaped.

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. Note that if a % is not followed by 2 hex digits, it will always be escaped.

encodeFragment

public static String encodeFragment(String value,
 boolean ignoreEscaped)

Encodes a string so as to produce a valid fragment, as defined by the RFC. Only excluded characters, such as space and #, are escaped.

Parameters:

ignoreEscaped - true to leave % characters unescaped if they already begin a valid three-character escape sequence; false to encode all % characters. Note that if a % is not followed by 2 hex digits, it will always be escaped.

decode

public static String decode(String value)

Decodes the given string by interpreting three-digit escape sequences as the bytes of a UTF-8 encoded character and replacing them with the characters they represent. Incomplete escape sequences are ignored and invalid UTF-8 encoded bytes are treated as extended ASCII characters.