Class HostAndPort

  • All Implemented Interfaces:
    Serializable

    @Immutable
    @GwtCompatible
    public final class HostAndPort
    extends Object
    implements 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
    Author:
    Paul Marks
    See Also:
    Serialized Form
    • Method Detail

      • getHost

        public 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:
        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​(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:
        IllegalArgumentException - if host contains a port number, or port is out of range.
      • fromHost

        public static HostAndPort fromHost​(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:
        IllegalArgumentException - if host contains a port number.
        Since:
        17.0
      • fromString

        public static HostAndPort fromString​(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:
        IllegalArgumentException - if nothing meaningful could be parsed.
      • 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:
        IllegalArgumentException - if bracketless IPv6 is detected.
      • equals

        public boolean equals​(@CheckForNull
                              Object other)
        Description copied from class: java.lang.Object
        Indicates whether some other object is "equal to" this one.

        The equals method implements an equivalence relation on non-null object references:

        • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
        • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
        • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
        • It is consistent: for any non-null reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the objects is modified.
        • For any non-null reference value x, x.equals(null) should return false.

        The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference values x and y, this method returns true if and only if x and y refer to the same object (x == y has the value true).

        Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.

        Overrides:
        equals in class Object
        Parameters:
        other - the reference object with which to compare.
        Returns:
        true if this object is the same as the obj argument; false otherwise.
        See Also:
        Object.hashCode(), HashMap
      • hashCode

        public int hashCode()
        Description copied from class: java.lang.Object
        Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

        The general contract of hashCode is:

        • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
        • If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
        • It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

        As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)

        Overrides:
        hashCode in class Object
        Returns:
        a hash code value for this object.
        See Also:
        Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)
      • toString

        public String toString()
        Rebuild the host:port string, including brackets if necessary.
        Overrides:
        toString in class Object
        Returns:
        a string representation of the object.