Class HostAndPort

  • All Implemented Interfaces:
    java.io.Serializable

    public final class HostAndPort
    extends java.lang.Object
    implements java.io.Serializable
    An immutable representation of a host and port.

    Example usage:

     HostAndPort hp = HostAndPort.fromString("[2001:db8::1]")
         .withDefaultPort(80)
         .requireBracketsForIPv6();
     hp.getHost();   // returns "2001:db8::1"
     hp.getPort();   // returns 80
     hp.toString();  // returns "[2001:db8::1]:80"
     

    Here are some examples of recognized formats:

    Note that this is not an exhaustive list, because these methods are only concerned with brackets, colons, and port numbers. Full validation of the host field (if desired) is the caller's responsibility.

    Since:
    10.0
    See Also:
    Serialized Form
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private boolean hasBracketlessColons
      True if the parsed host has colons, but no surrounding brackets.
      private java.lang.String host
      Hostname, IPv4/IPv6 literal, or unvalidated nonsense.
      private static int NO_PORT
      Magic value indicating the absence of a port number.
      private int port
      Validated port number in the range [0..65535], or NO_PORT
      private static long serialVersionUID  
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private HostAndPort​(java.lang.String host, int port, boolean hasBracketlessColons)  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object other)  
      static HostAndPort fromHost​(java.lang.String host)
      Build a HostAndPort instance from a host only.
      static HostAndPort fromParts​(java.lang.String host, int port)
      Build a HostAndPort instance from separate host and port values.
      static HostAndPort fromString​(java.lang.String hostPortString)
      Split a freeform string into a host and port, without strict validation.
      java.lang.String getHost()
      Returns the portion of this HostAndPort instance that should represent the hostname or IPv4/IPv6 literal.
      private static java.lang.String[] getHostAndPortFromBracketedHost​(java.lang.String hostPortString)
      Parses a bracketed host-port string, throwing IllegalArgumentException if parsing fails.
      int getPort()
      Get the current port number, failing if no port is defined.
      int getPortOrDefault​(int defaultPort)
      Returns the current port number, with a default if no port is defined.
      int hashCode()  
      boolean hasPort()
      Return true if this instance has a defined port.
      private static boolean isValidPort​(int port)
      Return true for valid port numbers.
      HostAndPort requireBracketsForIPv6()
      Generate an error if the host might be a non-bracketed IPv6 literal.
      java.lang.String toString()
      Rebuild the host:port string, including brackets if necessary.
      HostAndPort withDefaultPort​(int defaultPort)
      Provide a default port if the parsed string contained only a host.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
    • Field Detail

      • NO_PORT

        private static final int NO_PORT
        Magic value indicating the absence of a port number.
        See Also:
        Constant Field Values
      • host

        private final java.lang.String host
        Hostname, IPv4/IPv6 literal, or unvalidated nonsense.
      • port

        private final int port
        Validated port number in the range [0..65535], or NO_PORT
      • hasBracketlessColons

        private final boolean hasBracketlessColons
        True if the parsed host has colons, but no surrounding brackets.
    • Constructor Detail

      • HostAndPort

        private HostAndPort​(java.lang.String host,
                            int port,
                            boolean hasBracketlessColons)
    • Method Detail

      • getHost

        public java.lang.String getHost()
        Returns the portion of this HostAndPort instance that should represent the hostname or IPv4/IPv6 literal.

        A successful parse does not imply any degree of sanity in this field. For additional validation, see the HostSpecifier class.

        Since:
        20.0 (since 10.0 as getHostText)
      • hasPort

        public boolean hasPort()
        Return true if this instance has a defined port.
      • getPort

        public int getPort()
        Get the current port number, failing if no port is defined.
        Returns:
        a validated port number, in the range [0..65535]
        Throws:
        java.lang.IllegalStateException - if no port is defined. You can use withDefaultPort(int) to prevent this from occurring.
      • getPortOrDefault

        public int getPortOrDefault​(int defaultPort)
        Returns the current port number, with a default if no port is defined.
      • fromParts

        public static HostAndPort fromParts​(java.lang.String host,
                                            int port)
        Build a HostAndPort instance from separate host and port values.

        Note: Non-bracketed IPv6 literals are allowed. Use requireBracketsForIPv6() to prohibit these.

        Parameters:
        host - the host string to parse. Must not contain a port number.
        port - a port number from [0..65535]
        Returns:
        if parsing was successful, a populated HostAndPort object.
        Throws:
        java.lang.IllegalArgumentException - if host contains a port number, or port is out of range.
      • fromHost

        public static HostAndPort fromHost​(java.lang.String host)
        Build a HostAndPort instance from a host only.

        Note: Non-bracketed IPv6 literals are allowed. Use requireBracketsForIPv6() to prohibit these.

        Parameters:
        host - the host-only string to parse. Must not contain a port number.
        Returns:
        if parsing was successful, a populated HostAndPort object.
        Throws:
        java.lang.IllegalArgumentException - if host contains a port number.
        Since:
        17.0
      • fromString

        public static HostAndPort fromString​(java.lang.String hostPortString)
        Split a freeform string into a host and port, without strict validation.

        Note that the host-only formats will leave the port field undefined. You can use withDefaultPort(int) to patch in a default value.

        Parameters:
        hostPortString - the input string to parse.
        Returns:
        if parsing was successful, a populated HostAndPort object.
        Throws:
        java.lang.IllegalArgumentException - if nothing meaningful could be parsed.
      • getHostAndPortFromBracketedHost

        private static java.lang.String[] getHostAndPortFromBracketedHost​(java.lang.String hostPortString)
        Parses a bracketed host-port string, throwing IllegalArgumentException if parsing fails.
        Parameters:
        hostPortString - the full bracketed host-port specification. Post might not be specified.
        Returns:
        an array with 2 strings: host and port, in that order.
        Throws:
        java.lang.IllegalArgumentException - if parsing the bracketed host-port string fails.
      • withDefaultPort

        public HostAndPort withDefaultPort​(int defaultPort)
        Provide a default port if the parsed string contained only a host.

        You can chain this after fromString(String) to include a port in case the port was omitted from the input string. If a port was already provided, then this method is a no-op.

        Parameters:
        defaultPort - a port number, from [0..65535]
        Returns:
        a HostAndPort instance, guaranteed to have a defined port.
      • requireBracketsForIPv6

        public HostAndPort requireBracketsForIPv6()
        Generate an error if the host might be a non-bracketed IPv6 literal.

        URI formatting requires that IPv6 literals be surrounded by brackets, like "[2001:db8::1]". Chain this call after fromString(String) to increase the strictness of the parser, and disallow IPv6 literals that don't contain these brackets.

        Note that this parser identifies IPv6 literals solely based on the presence of a colon. To perform actual validation of IP addresses, see the InetAddresses.forString(String) method.

        Returns:
        this, to enable chaining of calls.
        Throws:
        java.lang.IllegalArgumentException - if bracketless IPv6 is detected.
      • equals

        public boolean equals​(@CheckForNull
                              java.lang.Object other)
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object
      • toString

        public java.lang.String toString()
        Rebuild the host:port string, including brackets if necessary.
        Overrides:
        toString in class java.lang.Object
      • isValidPort

        private static boolean isValidPort​(int port)
        Return true for valid port numbers.