Class HostAndPort

java.lang.Object
com.google.common.net.HostAndPort
All Implemented Interfaces:
Serializable

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
See Also:
  • Field Summary

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

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

    Modifier and Type
    Method
    Description
    boolean
    equals(Object other)
     
    Build a HostAndPort instance from a host only.
    fromParts(String host, int port)
    Build a HostAndPort instance from separate host and port values.
    fromString(String hostPortString)
    Split a freeform string into a host and port, without strict validation.
    Returns the portion of this HostAndPort instance that should represent the hostname or IPv4/IPv6 literal.
    private static String[]
    Parses a bracketed host-port string, throwing IllegalArgumentException if parsing fails.
    int
    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
     
    boolean
    Return true if this instance has a defined port.
    private static boolean
    isValidPort(int port)
    Return true for valid port numbers.
    Generate an error if the host might be a non-bracketed IPv6 literal.
    Rebuild the host:port string, including brackets if necessary.
    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 Details

    • NO_PORT

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

      private final 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.
    • serialVersionUID

      private static final long serialVersionUID
      See Also:
  • Constructor Details

    • HostAndPort

      private HostAndPort(String host, int port, boolean hasBracketlessColons)
  • Method Details

    • 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.
    • getHostAndPortFromBracketedHost

      private static String[] getHostAndPortFromBracketedHost(String hostPortString)
      Parses a bracketed host-port string, throwing IllegalArgumentException if parsing fails.
      Parameters:
      hostPortString - the full bracketed host-port specification. Port might not be specified.
      Returns:
      an array with 2 strings: host and port, in that order.
      Throws:
      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:
      IllegalArgumentException - if bracketless IPv6 is detected.
    • equals

      public boolean equals(@CheckForNull Object other)
      Overrides:
      equals in class Object
    • hashCode

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

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

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