NetUtil

java.lang.Object
- org.jboss.netty.util.NetUtil

```
public final class NetUtil
extends java.lang.Object
```
A class that holds a number of network-related constants.
This class borrowed some of its methods from a modified fork of the Inet6Util class which was part of Apache Harmony.

Field Summary

Fields
Modifier and Type	Field and Description
`private static int`	`IPV4_BYTE_COUNT` Number of bytes needed to represent and IPV4 value
`private static int`	`IPV4_MAX_CHAR_BETWEEN_SEPARATOR` Maximum amount of value adding characters in between IPV4 separators
`private static int`	`IPV4_SEPARATORS` Number of separators that must be present in an IPv4 string
`private static int`	`IPV6_BYTE_COUNT` Number of bytes needed to represent and IPV6 value
`private static int`	`IPV6_MAX_CHAR_BETWEEN_SEPARATOR` Maximum amount of value adding characters in between IPV6 separators
`private static int`	`IPV6_MAX_CHAR_COUNT` The maximum number of characters for an IPV6 string with no scope
`private static int`	`IPV6_MAX_SEPARATORS` Maximum number of separators that must be present in an IPv6 string
`private static int`	`IPV6_MIN_SEPARATORS` Minimum number of separators that must be present in an IPv6 string
`private static int`	`IPV6_WORD_COUNT` This defines how many words (represented as ints) are needed to represent an IPv6 address
`private static InternalLogger`	`logger` The logger being used by this class

Constructor Summary

Constructors
Modifier Constructor and Description

private NetUtil()
A constructor to stop this class being constructed.

Constructors
Modifier	Constructor and Description
`private`	`NetUtil()` A constructor to stop this class being constructed.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`private static void`	`convertToBytes(java.lang.String hexWord, byte[] ipByteArray, int byteIndex)` Converts a 4 character hex word into a 2 byte word equivalent
`static byte[]`	`createByteArrayFromIpAddressString(java.lang.String ipAddressString)` Creates an byte[] based on an ipAddressString.
`static java.net.Inet6Address`	`getByName(java.lang.CharSequence ip)` Returns the `Inet6Address` representation of a `CharSequence` IP address.
`static java.net.Inet6Address`	`getByName(java.lang.CharSequence ip, boolean ipv4Mapped)` Returns the `Inet6Address` representation of a `CharSequence` IP address.
`(package private) static int`	`getIntValue(char c)`
`private static boolean`	`inRangeEndExclusive(int value, int start, int end)` Does a range check on `value` if is within `start` (inclusive) and `end` (exclusive).
`private static boolean`	`isValidHexChar(char c)`
`static boolean`	`isValidIp4Word(java.lang.String word)`
`static boolean`	`isValidIpV4Address(java.lang.String value)` Takes a string and parses it to see if it is a valid IPV4 address.
`static boolean`	`isValidIpV6Address(java.lang.String ipAddress)`
`private static boolean`	`isValidNumericChar(char c)`
`static java.lang.String`	`toAddressString(java.net.InetAddress ip)` Returns the `String` representation of an `InetAddress`.
`static java.lang.String`	`toAddressString(java.net.InetAddress ip, boolean ipv4Mapped)` Returns the `String` representation of an `InetAddress`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - IPV6_WORD_COUNT
```
private static final int IPV6_WORD_COUNT
```
    This defines how many words (represented as ints) are needed to represent an IPv6 address
    
    See Also:
    
    Constant Field Values
  - IPV6_MAX_CHAR_COUNT
```
private static final int IPV6_MAX_CHAR_COUNT
```
    The maximum number of characters for an IPV6 string with no scope
    
    See Also:
    
    Constant Field Values
  - IPV6_BYTE_COUNT
```
private static final int IPV6_BYTE_COUNT
```
    Number of bytes needed to represent and IPV6 value
    
    See Also:
    
    Constant Field Values
  - IPV6_MAX_CHAR_BETWEEN_SEPARATOR
```
private static final int IPV6_MAX_CHAR_BETWEEN_SEPARATOR
```
    Maximum amount of value adding characters in between IPV6 separators
    
    See Also:
    
    Constant Field Values
  - IPV6_MIN_SEPARATORS
```
private static final int IPV6_MIN_SEPARATORS
```
    Minimum number of separators that must be present in an IPv6 string
    
    See Also:
    
    Constant Field Values
  - IPV6_MAX_SEPARATORS
```
private static final int IPV6_MAX_SEPARATORS
```
    Maximum number of separators that must be present in an IPv6 string
    
    See Also:
    
    Constant Field Values
  - IPV4_BYTE_COUNT
```
private static final int IPV4_BYTE_COUNT
```
    Number of bytes needed to represent and IPV4 value
    
    See Also:
    
    Constant Field Values
  - IPV4_MAX_CHAR_BETWEEN_SEPARATOR
```
private static final int IPV4_MAX_CHAR_BETWEEN_SEPARATOR
```
    Maximum amount of value adding characters in between IPV4 separators
    
    See Also:
    
    Constant Field Values
  - IPV4_SEPARATORS
```
private static final int IPV4_SEPARATORS
```
    Number of separators that must be present in an IPv4 string
    
    See Also:
    
    Constant Field Values
  - logger
```
private static final InternalLogger logger
```
    The logger being used by this class
- Constructor Detail
  - NetUtil
```
private NetUtil()
```
    A constructor to stop this class being constructed.
- Method Detail
  - createByteArrayFromIpAddressString
```
public static byte[] createByteArrayFromIpAddressString(java.lang.String ipAddressString)
```
    Creates an byte[] based on an ipAddressString. No error handling is performed here.
  - convertToBytes
```
private static void convertToBytes(java.lang.String hexWord,
                                   byte[] ipByteArray,
                                   int byteIndex)
```
    Converts a 4 character hex word into a 2 byte word equivalent
  - getIntValue
```
static int getIntValue(char c)
```
  - isValidIpV6Address
```
public static boolean isValidIpV6Address(java.lang.String ipAddress)
```
  - isValidIp4Word
```
public static boolean isValidIp4Word(java.lang.String word)
```
  - isValidHexChar
```
private static boolean isValidHexChar(char c)
```
  - isValidNumericChar
```
private static boolean isValidNumericChar(char c)
```
  - isValidIpV4Address
```
public static boolean isValidIpV4Address(java.lang.String value)
```
    Takes a string and parses it to see if it is a valid IPV4 address.
    
    Returns:
    
    true, if the string represents an IPV4 address in dotted notation, false otherwise
  - getByName
```
public static java.net.Inet6Address getByName(java.lang.CharSequence ip)
```
    Returns the Inet6Address representation of a CharSequence IP address.
    This method will treat all IPv4 type addresses as "IPv4 mapped" (see getByName(CharSequence, boolean))
    
    Parameters:
    
    ip - CharSequence IP address to be converted to a Inet6Address
    
    Returns:
    
    Inet6Address representation of the ip or null if not a valid IP address.
  - getByName
```
public static java.net.Inet6Address getByName(java.lang.CharSequence ip,
                                              boolean ipv4Mapped)
```
    Returns the Inet6Address representation of a CharSequence IP address.
    The ipv4Mapped parameter specifies how IPv4 addresses should be treated. "IPv4 mapped" format as defined in rfc 4291 section 2 is supported.
    Parameters:
    
    ip - CharSequence IP address to be converted to a Inet6Address
    ipv4Mapped -
    
    true To allow IPv4 mapped inputs to be translated into Inet6Address
    
    false Don't turn IPv4 addressed to mapped addresses
    Returns:
    
    Inet6Address representation of the ip or null if not a valid IP address.
  - toAddressString
```
public static java.lang.String toAddressString(java.net.InetAddress ip)
```
    Returns the String representation of an InetAddress.
    - Inet4Address results are identical to InetAddress.getHostAddress()
    - Inet6Address results adhere to rfc 5952 section 4
    The output does not include Scope ID.
    Parameters:
    
    ip - InetAddress to be converted to an address string
    
    Returns:
    
    String containing the text-formatted IP address
  - toAddressString
```
public static java.lang.String toAddressString(java.net.InetAddress ip,
                                               boolean ipv4Mapped)
```
    Returns the String representation of an InetAddress.
    - Inet4Address results are identical to InetAddress.getHostAddress()
    - Inet6Address results adhere to rfc 5952 section 4 if ipv4Mapped is false. If ipv4Mapped is true then "IPv4 mapped" format from rfc 4291 section 2 will be supported. The compressed result will always obey the compression rules defined in rfc 5952 section 4
    The output does not include Scope ID.
    Parameters:
    
    ip - InetAddress to be converted to an address string
    ipv4Mapped -
    
    true to stray from strict rfc 5952 and support the "IPv4 mapped" format defined in rfc 4291 section 2 while still following the updated guidelines in rfc 5952 section 4
    
    false to strictly follow rfc 5952
    Returns:
    
    String containing the text-formatted IP address
  - inRangeEndExclusive
```
private static boolean inRangeEndExclusive(int value,
                                           int start,
                                           int end)
```
    Does a range check on value if is within start (inclusive) and end (exclusive).
    Parameters:
    
    value - The value to checked if is within start (inclusive) and end (exclusive)
    
    start - The start of the range (inclusive)
    
    end - The end of the range (exclusive)
    
    Returns:
    true if value if is within start (inclusive) and end (exclusive)
    
    false otherwise

Class NetUtil

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

IPV6_WORD_COUNT

IPV6_MAX_CHAR_COUNT

IPV6_BYTE_COUNT

IPV6_MAX_CHAR_BETWEEN_SEPARATOR

IPV6_MIN_SEPARATORS

IPV6_MAX_SEPARATORS

IPV4_BYTE_COUNT

IPV4_MAX_CHAR_BETWEEN_SEPARATOR

IPV4_SEPARATORS

logger

Constructor Detail

NetUtil

Method Detail

createByteArrayFromIpAddressString

convertToBytes

getIntValue

isValidIpV6Address

isValidIp4Word

isValidHexChar

isValidNumericChar

isValidIpV4Address

getByName

getByName

toAddressString

toAddressString

inRangeEndExclusive