com.sun.enterprise.util.net

Class NetUtils

java.lang.Object

com.sun.enterprise.util.net.NetUtils

public class NetUtils
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	NetUtils.PortAvailability

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_PORT

Method Summary

Methods

Modifier and Type	Method and Description
static NetUtils.PortAvailability	checkPort(int portNumber) There are 4 possibilities when you want to setup a server socket on a port: 1.
static String	getCanonicalHostName() This method returns the fully qualified name of the host.
static Socket	getClientSocket(String host, int port, int msecTimeout)
static int	getFreePort() Gets a free port at the time of call to this method.
static int	getFreePort(String hostName, int startingPort, int endingPort) Returns a random port in the specified range
static InetAddress[]	getHostAddresses()
static String[]	getHostIPs()
static String	getHostName()
static int	getNextFreePort(String hostName, int port) Get the next free port (incrementing by 1)
static byte[]	ip2bytes(String ip)
static boolean	isEqual(String host1, String host2) Painfully thorough error-handling.
static boolean	isLocal(String ip)
static boolean	isLocalHost(String ip)
static boolean	isPortFree(int portNumber)
static boolean	isPortFree(String hostName, int portNumber)
static boolean	isPortStringValid(String portNumber)
static boolean	isPortValid(int portNumber)
static boolean	isRemote(String ip)
static boolean	isRunning(int port) convenience method for the local machine
static boolean	isRunning(String host, int port)
static boolean	isRunning(String host, int port, int timeoutMilliseconds) There is sometimes a need for subclasses to know if a local domain is running.
static boolean	isSecurePort(String hostname, int port) This method accepts a hostname and port #.
static boolean	isThisHostLocal(String hostname) Return true if hostname represents the current machine.
static void	main(String[] args)
static String	trimIP(String ip)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_PORT

public static final int MAX_PORT

See Also:

Constant Field Values

Method Detail

isThisHostLocal

public static boolean isThisHostLocal(String hostname)

Return true if hostname represents the current machine. A null or empty hostname is considered local, as is the name "localhost". Otherwise, all the IP addresses corresponding to hostname are compared with all the IP addresses corresponding to "localhost", as well as all the IP addresses for all the network interfaces on this machine. Note that hostname can also be an IP address in string form.

Returns:

true if hostname is the local host

isEqual

public static boolean isEqual(String host1,
              String host2)

Painfully thorough error-handling. Some would say over-engineered but I plan on never looking at this code again!

Parameters:

host1 -

host2 -

Returns:

getClientSocket

public static Socket getClientSocket(String host,
                     int port,
                     int msecTimeout)

getHostName

public static String getHostName()

getCanonicalHostName

public static String getCanonicalHostName()
                                   throws UnknownHostException

This method returns the fully qualified name of the host. If the name can't be resolved (on windows if there isn't a domain specified), just host name is returned

Throws:

UnknownHostException - so it can be handled on a case by case basis

getHostAddresses

public static InetAddress[] getHostAddresses()

getHostIPs

public static String[] getHostIPs()

trimIP

public static String trimIP(String ip)

ip2bytes

public static byte[] ip2bytes(String ip)

isLocalHost

public static boolean isLocalHost(String ip)

isLocal

public static boolean isLocal(String ip)

isRemote

public static boolean isRemote(String ip)

getNextFreePort

public static int getNextFreePort(String hostName,
                  int port)

Get the next free port (incrementing by 1)

Parameters:

hostName - The host name on which the port is to be obtained

port - The port number

Returns:

The next incremental port number or 0 if a port cannot be found.

getFreePort

public static int getFreePort(String hostName,
              int startingPort,
              int endingPort)

Returns a random port in the specified range

Parameters:

hostName - The host on which the port is to be obtained.

startingPort - starting port in the range

endingPort - ending port in the range

Returns:

the new port or 0 if the range is invalid.

isPortValid

public static boolean isPortValid(int portNumber)

isPortStringValid

public static boolean isPortStringValid(String portNumber)

isPortFree

public static boolean isPortFree(String hostName,
                 int portNumber)

checkPort

public static NetUtils.PortAvailability checkPort(int portNumber)

There are 4 possibilities when you want to setup a server socket on a port: 1. The port is already in use 2. The user does not have permission to open up shop on that port An example of (2) is a non-root user on UNIX trying to use port 80 3. The port number is not in the legal range 4. OK -- you can use it!

Parameters:

portNumber -

Returns:

one of the 4 possibilities for this port

isPortFree

public static boolean isPortFree(int portNumber)

getFreePort

public static int getFreePort()

Gets a free port at the time of call to this method. The logic leverages the built in java.net.ServerSocket implementation which binds a server socket to a free port when instantiated with a port 0 .

Note that this method guarantees the availability of the port only at the time of call. The method does not bind to this port.

Checking for free port can fail for several reasons which may indicate potential problems with the system. This method acknowledges the fact and following is the general contract:

Best effort is made to find a port which can be bound to. All the exceptional conditions in the due course are considered SEVERE. If any exceptional condition is experienced, 0 is returned, indicating that the method failed for some reasons and the callers should take the corrective action. (The method need not always throw an exception for this). Method is synchronized on this class.

Returns:

integer depicting the free port number available at this time 0 otherwise.

isSecurePort

public static boolean isSecurePort(String hostname,
                   int port)
                            throws IOException,
                                   ConnectException,
                                   SocketTimeoutException

This method accepts a hostname and port #. It uses this information to attempt to connect to the port, send a test query, analyze the result to determine if the port is secure or unsecure (currently only http / https is supported).

Parameters:

hostname - - String name of the host where the connections has to be made

port - - int name of the port where the connections has to be made

Returns:

admin password

Throws:

IOException - if an error occurs during the connection

ConnectException - if an error occurred while attempting to connect a socket to a remote address and port.

SocketTimeoutException - if timeout(4s) expires before connecting

isRunning

public static boolean isRunning(String host,
                int port,
                int timeoutMilliseconds)

There is sometimes a need for subclasses to know if a local domain is running. An example of such a command is change-master-password command. The stop-domain command also needs to know if a domain is running without having to provide user name and password on command line (this is the case when I own a domain that has non-default admin user and password) and want to stop it without providing it.

In such cases, we need to know if the domain is running and this method provides a way to do that.

Parameters:

the - timeout in milliseconds

Returns:

boolean indicating whether the server is running

isRunning

public static boolean isRunning(String host,
                int port)

isRunning

public static final boolean isRunning(int port)

convenience method for the local machine

main

public static void main(String[] args)