org.apache.xml.utils
Class URI

java.lang.Object
  org.apache.xml.utils.URI

All Implemented Interfaces:

Serializable

public class URI

extends Object

implements Serializable

A class to represent a Uniform Resource Identifier (URI). This class is designed to handle the parsing of URIs and provide access to the various components (scheme, host, port, userinfo, path, query string and fragment) that may constitute a URI.

Parsing of a URI specification is done according to the URI syntax described in RFC 2396 . Every URI consists of a scheme, followed by a colon (':'), followed by a scheme-specific part. For URIs that follow the "generic URI" syntax, the scheme- specific part begins with two slashes ("//") and may be followed by an authority segment (comprised of user information, host, and port), path segment, query segment and fragment. Note that RFC 2396 no longer specifies the use of the parameters segment and excludes the "user:password" syntax as part of the authority segment. If "user:password" appears in a URI, the entire user/password string is stored as userinfo.

For URIs that do not follow the "generic URI" syntax (e.g. mailto), the entire scheme-specific part is treated as the "path" portion of the URI.

Note that, unlike the java.net.URL class, this class does not provide any built-in network access functionality nor does it provide any scheme-specific functionality (for example, it does not know a default port for a specific scheme). Rather, it only knows the grammar and basic set of operations that can be applied to a URI.

See Also:

Serialized Form

Nested Class Summary

static class

URI.MalformedURIException MalformedURIExceptions are thrown in the process of building a URI or setting fields on a URI when an operation would result in an invalid URI specification.

Field Summary

private static boolean	DEBUG Indicate whether in DEBUG mode
private String	m_fragment If specified, stores the fragment for this URI; otherwise null.
private String	m_host If specified, stores the host for this URI; otherwise null.
private String	m_path If specified, stores the path for this URI; otherwise null.
private int	m_port If specified, stores the port for this URI; otherwise -1.
private String	m_queryString If specified, stores the query string for this URI; otherwise null.
private String	m_scheme Stores the scheme (usually the protocol) for this URI.
private String	m_userinfo If specified, stores the userinfo for this URI; otherwise null.
private static String	MARK_CHARACTERS URI punctuation mark characters - these, combined with alphanumerics, constitute the "unreserved" characters
private static String	RESERVED_CHARACTERS reserved characters
private static String	SCHEME_CHARACTERS scheme can be composed of alphanumerics and these characters
private static String	USERINFO_CHARACTERS userinfo can be composed of unreserved, escaped and these characters

Constructor Summary

URI()
Construct a new and uninitialized URI.

URI(String p_uriSpec)
Construct a new URI from a URI specification string.

URI(String p_scheme, String p_schemeSpecificPart)
Construct a new URI that does not follow the generic URI syntax.

URI(String p_scheme, String p_userinfo, String p_host, int p_port, String p_path, String p_queryString, String p_fragment)
Construct a new URI that follows the generic URI syntax from its component parts.

URI(String p_scheme, String p_host, String p_path, String p_queryString, String p_fragment)
Construct a new URI that follows the generic URI syntax from its component parts.

URI(URI p_other)
Construct a new URI from another URI.

URI(URI p_base, String p_uriSpec)
Construct a new URI from a base URI and a URI specification string.

Method Summary

void	appendPath(String p_addToPath) Append to the end of the path of this URI.
boolean	equals(Object p_test) Determines if the passed-in Object is equivalent to this URI.
String	getFragment() Get the fragment for this URI.
String	getHost() Get the host for this URI.
String	getPath() Get the path for this URI.
String	getPath(boolean p_includeQueryString, boolean p_includeFragment) Get the path for this URI (optionally with the query string and fragment).
int	getPort() Get the port for this URI.
String	getQueryString() Get the query string for this URI.
String	getScheme() Get the scheme for this URI.
String	getSchemeSpecificPart() Get the scheme-specific part for this URI (everything following the scheme and the first colon).
String	getUserinfo() Get the userinfo for this URI.
private void	initialize(URI p_other) Initialize all fields of this URI from another URI.
private void	initialize(URI p_base, String p_uriSpec) Initializes this URI from a base URI and a URI specification string.
private void	initializeAuthority(String p_uriSpec) Initialize the authority (userinfo, host and port) for this URI from a URI string spec.
private void	initializePath(String p_uriSpec) Initialize the path for this URI from a URI string spec.
private void	initializeScheme(String p_uriSpec) Initialize the scheme for this URI from a URI string spec.
private static boolean	isAlpha(char p_char) Determine whether a char is an alphabetic character: a-z or A-Z
private static boolean	isAlphanum(char p_char) Determine whether a char is an alphanumeric: 0-9, a-z or A-Z
static boolean	isConformantSchemeName(String p_scheme) Determine whether a scheme conforms to the rules for a scheme name.
private static boolean	isDigit(char p_char) Determine whether a char is a digit.
boolean	isGenericURI() Get the indicator as to whether this URI uses the "generic URI" syntax.
private static boolean	isHex(char p_char) Determine whether a character is a hexadecimal character.
private static boolean	isReservedCharacter(char p_char) Determine whether a character is a reserved character: ';', '/', '?'
private static boolean	isUnreservedCharacter(char p_char) Determine whether a char is an unreserved character.
private static boolean	isURIString(String p_uric) Determine whether a given string contains only URI characters (also called "uric" in RFC 2396). uric consist of all reserved characters, unreserved characters and escaped characters.
static boolean	isWellFormedAddress(String p_address) Determine whether a string is syntactically capable of representing a valid IPv4 address or the domain name of a network host.
void	setFragment(String p_fragment) Set the fragment for this URI.
void	setHost(String p_host) Set the host for this URI.
void	setPath(String p_path) Set the path for this URI.
void	setPort(int p_port) Set the port for this URI. -1 is used to indicate that the port is not specified, otherwise valid port numbers are between 0 and 65535.
void	setQueryString(String p_queryString) Set the query string for this URI.
void	setScheme(String p_scheme) Set the scheme for this URI.
void	setUserinfo(String p_userinfo) Set the userinfo for this URI.
String	toString() Get the URI as a string specification.

Methods inherited from class java.lang.Object

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

Field Detail

RESERVED_CHARACTERS

private static final String RESERVED_CHARACTERS

reserved characters

See Also:

Constant Field Values

MARK_CHARACTERS

private static final String MARK_CHARACTERS

URI punctuation mark characters - these, combined with alphanumerics, constitute the "unreserved" characters

See Also:

Constant Field Values

SCHEME_CHARACTERS

private static final String SCHEME_CHARACTERS

scheme can be composed of alphanumerics and these characters

See Also:

Constant Field Values

USERINFO_CHARACTERS

private static final String USERINFO_CHARACTERS

userinfo can be composed of unreserved, escaped and these characters

See Also:

Constant Field Values

m_scheme

private String m_scheme

Stores the scheme (usually the protocol) for this URI.

m_userinfo

private String m_userinfo

If specified, stores the userinfo for this URI; otherwise null.

m_host

private String m_host

If specified, stores the host for this URI; otherwise null.

m_port

private int m_port

If specified, stores the port for this URI; otherwise -1.

m_path

private String m_path

If specified, stores the path for this URI; otherwise null.

m_queryString

private String m_queryString

If specified, stores the query string for this URI; otherwise null.

m_fragment

private String m_fragment

If specified, stores the fragment for this URI; otherwise null.

DEBUG

private static boolean DEBUG

Indicate whether in DEBUG mode

Constructor Detail

URI

public URI()

Construct a new and uninitialized URI.

URI

public URI(URI p_other)

Construct a new URI from another URI. All fields for this URI are set equal to the fields of the URI passed in.

Parameters:

p_other - the URI to copy (cannot be null)

URI

public URI(String p_uriSpec)
    throws URI.MalformedURIException

Construct a new URI from a URI specification string. If the specification follows the "generic URI" syntax, (two slashes following the first colon), the specification will be parsed accordingly - setting the scheme, userinfo, host,port, path, query string and fragment fields as necessary. If the specification does not follow the "generic URI" syntax, the specification is parsed into a scheme and scheme-specific part (stored as the path) only.

Parameters:

p_uriSpec - the URI specification string (cannot be null or empty)

Throws:

URI.MalformedURIException - if p_uriSpec violates any syntax rules

URI

public URI(URI p_base,
           String p_uriSpec)
    throws URI.MalformedURIException

Construct a new URI from a base URI and a URI specification string. The URI specification string may be a relative URI.

Parameters:

p_base - the base URI (cannot be null if p_uriSpec is null or empty)

p_uriSpec - the URI specification string (cannot be null or empty if p_base is null)

Throws:

URI.MalformedURIException - if p_uriSpec violates any syntax rules

URI

public URI(String p_scheme,
           String p_schemeSpecificPart)
    throws URI.MalformedURIException

Construct a new URI that does not follow the generic URI syntax. Only the scheme and scheme-specific part (stored as the path) are initialized.

Parameters:

p_scheme - the URI scheme (cannot be null or empty)

p_schemeSpecificPart - the scheme-specific part (cannot be null or empty)

Throws:

URI.MalformedURIException - if p_scheme violates any syntax rules

URI

public URI(String p_scheme,
           String p_host,
           String p_path,
           String p_queryString,
           String p_fragment)
    throws URI.MalformedURIException

Construct a new URI that follows the generic URI syntax from its component parts. Each component is validated for syntax and some basic semantic checks are performed as well. See the individual setter methods for specifics.

Parameters:

p_scheme - the URI scheme (cannot be null or empty)

p_host - the hostname or IPv4 address for the URI

p_path - the URI path - if the path contains '?' or '#', then the query string and/or fragment will be set from the path; however, if the query and fragment are specified both in the path and as separate parameters, an exception is thrown

p_queryString - the URI query string (cannot be specified if path is null)

p_fragment - the URI fragment (cannot be specified if path is null)

Throws:

URI.MalformedURIException - if any of the parameters violates syntax rules or semantic rules

URI

public URI(String p_scheme,
           String p_userinfo,
           String p_host,
           int p_port,
           String p_path,
           String p_queryString,
           String p_fragment)
    throws URI.MalformedURIException

Construct a new URI that follows the generic URI syntax from its component parts. Each component is validated for syntax and some basic semantic checks are performed as well. See the individual setter methods for specifics.

Parameters:

p_scheme - the URI scheme (cannot be null or empty)

p_userinfo - the URI userinfo (cannot be specified if host is null)

p_host - the hostname or IPv4 address for the URI

p_port - the URI port (may be -1 for "unspecified"; cannot be specified if host is null)

p_path - the URI path - if the path contains '?' or '#', then the query string and/or fragment will be set from the path; however, if the query and fragment are specified both in the path and as separate parameters, an exception is thrown

p_queryString - the URI query string (cannot be specified if path is null)

p_fragment - the URI fragment (cannot be specified if path is null)

Throws:

URI.MalformedURIException - if any of the parameters violates syntax rules or semantic rules

Method Detail

initialize

private void initialize(URI p_other)

Initialize all fields of this URI from another URI.

Parameters:

p_other - the URI to copy (cannot be null)

initialize

private void initialize(URI p_base,
                        String p_uriSpec)
                 throws URI.MalformedURIException

Initializes this URI from a base URI and a URI specification string. See RFC 2396 Section 4 and Appendix B for specifications on parsing the URI and Section 5 for specifications on resolving relative URIs and relative paths.

Parameters:

p_base - the base URI (may be null if p_uriSpec is an absolute URI)

p_uriSpec - the URI spec string which may be an absolute or relative URI (can only be null/empty if p_base is not null)

Throws:

URI.MalformedURIException - if p_base is null and p_uriSpec is not an absolute URI or if p_uriSpec violates syntax rules

initializeScheme

private void initializeScheme(String p_uriSpec)
                       throws URI.MalformedURIException

Initialize the scheme for this URI from a URI string spec.

Parameters:

p_uriSpec - the URI specification (cannot be null)

Throws:

URI.MalformedURIException - if URI does not have a conformant scheme

initializeAuthority

private void initializeAuthority(String p_uriSpec)
                          throws URI.MalformedURIException

Initialize the authority (userinfo, host and port) for this URI from a URI string spec.

Parameters:

p_uriSpec - the URI specification (cannot be null)

Throws:

URI.MalformedURIException - if p_uriSpec violates syntax rules

initializePath

private void initializePath(String p_uriSpec)
                     throws URI.MalformedURIException

Initialize the path for this URI from a URI string spec.

Parameters:

p_uriSpec - the URI specification (cannot be null)

Throws:

URI.MalformedURIException - if p_uriSpec violates syntax rules

getScheme

public String getScheme()

Get the scheme for this URI.

Returns:

the scheme for this URI

getSchemeSpecificPart

public String getSchemeSpecificPart()

Get the scheme-specific part for this URI (everything following the scheme and the first colon). See RFC 2396 Section 5.2 for spec.

Returns:

the scheme-specific part for this URI

getUserinfo

public String getUserinfo()

Get the userinfo for this URI.

Returns:

the userinfo for this URI (null if not specified).

getHost

public String getHost()

Get the host for this URI.

Returns:

the host for this URI (null if not specified).

getPort

public int getPort()

Get the port for this URI.

Returns:

the port for this URI (-1 if not specified).

getPath

public String getPath(boolean p_includeQueryString,
                      boolean p_includeFragment)

Get the path for this URI (optionally with the query string and fragment).

Parameters:

p_includeQueryString - if true (and query string is not null), then a "?" followed by the query string will be appended

p_includeFragment - if true (and fragment is not null), then a "#" followed by the fragment will be appended

Returns:

the path for this URI possibly including the query string and fragment

getPath

public String getPath()

Get the path for this URI. Note that the value returned is the path only and does not include the query string or fragment.

Returns:

the path for this URI.

getQueryString

public String getQueryString()

Get the query string for this URI.

Returns:

the query string for this URI. Null is returned if there was no "?" in the URI spec, empty string if there was a "?" but no query string following it.

getFragment

public String getFragment()

Get the fragment for this URI.

Returns:

the fragment for this URI. Null is returned if there was no "#" in the URI spec, empty string if there was a "#" but no fragment following it.

setScheme

public void setScheme(String p_scheme)
               throws URI.MalformedURIException

Set the scheme for this URI. The scheme is converted to lowercase before it is set.

Parameters:

p_scheme - the scheme for this URI (cannot be null)

Throws:

URI.MalformedURIException - if p_scheme is not a conformant scheme name

setUserinfo

public void setUserinfo(String p_userinfo)
                 throws URI.MalformedURIException

Set the userinfo for this URI. If a non-null value is passed in and the host value is null, then an exception is thrown.

Parameters:

p_userinfo - the userinfo for this URI

Throws:

URI.MalformedURIException - if p_userinfo contains invalid characters

setHost

public void setHost(String p_host)
             throws URI.MalformedURIException

Set the host for this URI. If null is passed in, the userinfo field is also set to null and the port is set to -1.

Parameters:

p_host - the host for this URI

Throws:

URI.MalformedURIException - if p_host is not a valid IP address or DNS hostname.

setPort

public void setPort(int p_port)
             throws URI.MalformedURIException

Set the port for this URI. -1 is used to indicate that the port is not specified, otherwise valid port numbers are between 0 and 65535. If a valid port number is passed in and the host field is null, an exception is thrown.

Parameters:

p_port - the port number for this URI

Throws:

URI.MalformedURIException - if p_port is not -1 and not a valid port number

setPath

public void setPath(String p_path)
             throws URI.MalformedURIException

Set the path for this URI. If the supplied path is null, then the query string and fragment are set to null as well. If the supplied path includes a query string and/or fragment, these fields will be parsed and set as well. Note that, for URIs following the "generic URI" syntax, the path specified should start with a slash. For URIs that do not follow the generic URI syntax, this method sets the scheme-specific part.

Parameters:

p_path - the path for this URI (may be null)

Throws:

URI.MalformedURIException - if p_path contains invalid characters

appendPath

public void appendPath(String p_addToPath)
                throws URI.MalformedURIException

Append to the end of the path of this URI. If the current path does not end in a slash and the path to be appended does not begin with a slash, a slash will be appended to the current path before the new segment is added. Also, if the current path ends in a slash and the new segment begins with a slash, the extra slash will be removed before the new segment is appended.

Parameters:

p_addToPath - the new segment to be added to the current path

Throws:

URI.MalformedURIException - if p_addToPath contains syntax errors

setQueryString

public void setQueryString(String p_queryString)
                    throws URI.MalformedURIException

Set the query string for this URI. A non-null value is valid only if this is an URI conforming to the generic URI syntax and the path value is not null.

Parameters:

p_queryString - the query string for this URI

Throws:

URI.MalformedURIException - if p_queryString is not null and this URI does not conform to the generic URI syntax or if the path is null

setFragment

public void setFragment(String p_fragment)
                 throws URI.MalformedURIException

Set the fragment for this URI. A non-null value is valid only if this is a URI conforming to the generic URI syntax and the path value is not null.

Parameters:

p_fragment - the fragment for this URI

Throws:

URI.MalformedURIException - if p_fragment is not null and this URI does not conform to the generic URI syntax or if the path is null

equals

public boolean equals(Object p_test)

Determines if the passed-in Object is equivalent to this URI.

Overrides:

equals in class Object

Parameters:

p_test - the Object to test for equality.

Returns:

true if p_test is a URI with all values equal to this URI, false otherwise

See Also:

Object.hashCode(), Hashtable

toString

public String toString()

Get the URI as a string specification. See RFC 2396 Section 5.2.

Overrides:

toString in class Object

Returns:

the URI string specification

isGenericURI

public boolean isGenericURI()

Get the indicator as to whether this URI uses the "generic URI" syntax.

Returns:

true if this URI uses the "generic URI" syntax, false otherwise

isConformantSchemeName

public static boolean isConformantSchemeName(String p_scheme)

Determine whether a scheme conforms to the rules for a scheme name. A scheme is conformant if it starts with an alphanumeric, and contains only alphanumerics, '+','-' and '.'.

Parameters:

p_scheme - The sheme name to check

Returns:

true if the scheme is conformant, false otherwise

isWellFormedAddress

public static boolean isWellFormedAddress(String p_address)

Determine whether a string is syntactically capable of representing a valid IPv4 address or the domain name of a network host. A valid IPv4 address consists of four decimal digit groups separated by a '.'. A hostname consists of domain labels (each of which must begin and end with an alphanumeric but may contain '-') separated & by a '.'. See RFC 2396 Section 3.2.2.

Parameters:

p_address - The address string to check

Returns:

true if the string is a syntactically valid IPv4 address or hostname

isDigit

private static boolean isDigit(char p_char)

Determine whether a char is a digit.

Parameters:

p_char - the character to check

Returns:

true if the char is betweeen '0' and '9', false otherwise

isHex

private static boolean isHex(char p_char)

Determine whether a character is a hexadecimal character.

Parameters:

p_char - the character to check

Returns:

true if the char is betweeen '0' and '9', 'a' and 'f' or 'A' and 'F', false otherwise

isAlpha

private static boolean isAlpha(char p_char)

Determine whether a char is an alphabetic character: a-z or A-Z

Parameters:

p_char - the character to check

Returns:

true if the char is alphabetic, false otherwise

isAlphanum

private static boolean isAlphanum(char p_char)

Determine whether a char is an alphanumeric: 0-9, a-z or A-Z

Parameters:

p_char - the character to check

Returns:

true if the char is alphanumeric, false otherwise

isReservedCharacter

private static boolean isReservedCharacter(char p_char)

Determine whether a character is a reserved character: ';', '/', '?', ':', '@', '&', '=', '+', '$' or ','

Parameters:

p_char - the character to check

Returns:

true if the string contains any reserved characters

isUnreservedCharacter

private static boolean isUnreservedCharacter(char p_char)

Determine whether a char is an unreserved character.

Parameters:

p_char - the character to check

Returns:

true if the char is unreserved, false otherwise

isURIString

private static boolean isURIString(String p_uric)

Determine whether a given string contains only URI characters (also called "uric" in RFC 2396). uric consist of all reserved characters, unreserved characters and escaped characters.

Parameters:

p_uric - URI string

Returns:

true if the string is comprised of uric, false otherwise