Package com.sun.enterprise.util.net

Class NetUtils

java.lang.Object
com.sun.enterprise.util.net.NetUtils
public final class NetUtils extends Object

  • Field Details

  • Method Details

    • getFreePort

      public static int getFreePort() throws IllegalStateException
      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.

      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.

      Method is synchronized on this class.

      Returns:
      integer depicting the free port number available at this time
      Throws:
      IllegalStateException - if it was not possible to open and close the server socket.

    • 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 not in valid range.
      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 is already in use
      4. OK -- you can use it!
      Parameters:
      portNumber -
      Returns:
      one of the 4 possibilities for this port

    • isPortStringValid

      public static boolean isPortStringValid(String portNumber)

    • isPortValid

      public static boolean isPortValid(int portNumber)

    • isPortFree

      public static boolean isPortFree(int portNumber)

    • isPortFree

      public static boolean isPortFree(String hostName, int portNumber)

    • isRunning

      public static boolean isRunning(String host, int port)
      Calls isRunning(String, int, int) with 3000 ms timeout.
      Parameters:
      host -
      port - port to check.
      Returns:
      true if there's something listening on the port.

    • 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:
      timeoutMilliseconds - timeout in milliseconds
      Returns:
      true if there's something listening on th port.

    • isRemote

      public static boolean isRemote(String ip)

    • isLocal

      public static boolean isLocal(String ip)

    • 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

    • isSameHost

      public static boolean isSameHost(String host1, String host2)
      Resolves both hosts and then compares their internet addresses. If they match at least once, those hosts are considered as same. If there is no such address, returns false.
      Parameters:
      host1 -
      host2 -
      Returns:
      true if parameters resolved to same internet address(es)

    • getHostIPs

      public static String[] getHostIPs()

    • getHostAddresses

      public static InetAddress[] getHostAddresses()

    • 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
      Returns:
      fully qualified name of the local host.
      Throws:
      UnknownHostException - so it can be handled on a case by case basis