Class URI


  • public class URI
    extends Object
    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, and amended by RFC 2732.

    Every absolute 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.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      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.
    • Constructor Summary

      Constructors 
      Constructor Description
      URI​(String uriSpec)
      Construct a new URI from a URI specification string.
      URI​(String uriSpec, boolean allowNonAbsoluteURI)
      Construct a new URI from a URI specification string.
      URI​(String scheme, String userinfo, String host, int port, String path, String queryString, String fragment)
      Construct a new URI that follows the generic URI syntax from its component parts.
      URI​(String scheme, String host, String path, String queryString, String fragment)
      Construct a new URI that follows the generic URI syntax from its component parts.
      URI​(URI base, String uriSpec)
      Construct a new URI from a base URI and a URI specification string.
      URI​(URI base, String uriSpec, boolean allowNonAbsoluteURI)
      Construct a new URI from a base URI and a URI specification string.
    • Constructor Detail

      • URI

        public URI​(String 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:
        uriSpec - the URI specification string (cannot be null or empty)
        Throws:
        URI.MalformedURIException - if p_uriSpec violates any syntax rules
      • URI

        public URI​(String uriSpec,
                   boolean allowNonAbsoluteURI)
            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. Construct a relative URI if boolean is assigned to "true" and p_uriSpec is not valid absolute URI, instead of throwing an exception.
        Parameters:
        uriSpec - the URI specification string (cannot be null or empty)
        allowNonAbsoluteURI - true to permit non-absolute URIs, false otherwise.
        Throws:
        URI.MalformedURIException - if p_uriSpec violates any syntax rules
      • URI

        public URI​(URI base,
                   String 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:
        base - the base URI (cannot be null if p_uriSpec is null or empty)
        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​(URI base,
                   String uriSpec,
                   boolean allowNonAbsoluteURI)
            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. Construct a relative URI if boolean is assigned to "true" and p_uriSpec is not valid absolute URI and p_base is null instead of throwing an exception.
        Parameters:
        base - the base URI (cannot be null if p_uriSpec is null or empty)
        uriSpec - the URI specification string (cannot be null or empty if p_base is null)
        allowNonAbsoluteURI - true to permit non-absolute URIs, false otherwise.
        Throws:
        URI.MalformedURIException - if p_uriSpec violates any syntax rules
      • URI

        public URI​(String scheme,
                   String host,
                   String path,
                   String queryString,
                   String 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:
        scheme - the URI scheme (cannot be null or empty)
        host - the hostname, IPv4 address or IPv6 reference for the URI
        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
        queryString - the URI query string (cannot be specified if path is null)
        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 scheme,
                   String userinfo,
                   String host,
                   int port,
                   String path,
                   String queryString,
                   String 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:
        scheme - the URI scheme (cannot be null or empty)
        userinfo - the URI userinfo (cannot be specified if host is null)
        host - the hostname, IPv4 address or IPv6 reference for the URI
        port - the URI port (may be -1 for "unspecified"; cannot be specified if host is null)
        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
        queryString - the URI query string (cannot be specified if path is null)
        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

      • absolutize

        public void absolutize​(URI base)
        Absolutize URI with given base URI.
        Parameters:
        base - base URI for absolutization
      • 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).
      • getRegBasedAuthority

        public String getRegBasedAuthority()
        Get the registry based authority for this URI.
        Returns:
        the registry based authority (null if not specified).
      • 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 scheme)
                       throws URI.MalformedURIException
        Set the scheme for this URI. The scheme is converted to lowercase before it is set.
        Parameters:
        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 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:
        userinfo - the userinfo for this URI
        Throws:
        URI.MalformedURIException - if p_userinfo contains invalid characters
      • setHost

        public void setHost​(String 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.

        Note: This method overwrites registry based authority if it previously existed in this URI.

        Parameters:
        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 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:
        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 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:
        path - the path for this URI (may be null)
        Throws:
        URI.MalformedURIException - if p_path contains invalid characters
      • setQueryString

        public void setQueryString​(String 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:
        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 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:
        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 test)
        Determines if the passed-in Object is equivalent to this URI.
        Overrides:
        equals in class Object
        Parameters:
        test - the Object to test for equality.
        Returns:
        true if p_test is a URI with all values equal to this URI, false otherwise
      • 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
      • isAbsoluteURI

        public boolean isAbsoluteURI()
        Returns whether this URI represents an absolute URI.
        Returns:
        true if this URI represents an absolute URI, false otherwise
      • isWellFormedAddress

        public static boolean isWellFormedAddress​(String address)
        Determine whether a string is syntactically capable of representing a valid IPv4 address, IPv6 reference or the domain name of a network host. A valid IPv4 address consists of four decimal digit groups separated by a '.'. Each group must consist of one to three digits. See RFC 2732 Section 3, and RFC 2373 Section 2.2, for the definition of IPv6 references. 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:
        address - the address
        Returns:
        true if the string is a syntactically valid IPv4 address, IPv6 reference or hostname
      • isWellFormedIPv4Address

        public static boolean isWellFormedIPv4Address​(String address)

        Determines whether a string is an IPv4 address as defined by RFC 2373, and under the further constraint that it must be a 32-bit address. Though not expressed in the grammar, in order to satisfy the 32-bit address constraint, each segment of the address cannot be greater than 255 (8 bits of information).

        IPv4address = 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT

        Parameters:
        address - the address
        Returns:
        true if the string is a syntactically valid IPv4 address
      • isWellFormedIPv6Reference

        public static boolean isWellFormedIPv6Reference​(String address)

        Determines whether a string is an IPv6 reference as defined by RFC 2732, where IPv6address is defined in RFC 2373. The IPv6 address is parsed according to Section 2.2 of RFC 2373, with the additional constraint that the address be composed of 128 bits of information.

        IPv6reference = "[" IPv6address "]"

        Note: The BNF expressed in RFC 2373 Appendix B does not accurately describe section 2.2, and was in fact removed from RFC 3513, the successor of RFC 2373.

        Parameters:
        address - the address
        Returns:
        true if the string is a syntactically valid IPv6 reference