com.prosysopc.ua.stack.utils

Class OSUtil

java.lang.Object

com.prosysopc.ua.stack.utils.OSUtil

public class OSUtil
extends Object

A utility class dealing with operating system specific functions.

Helps identifying the operating system on which the current application is running with getOsName(), isWindows(), isLinux()m isMacOs() and isAndroid().

Also enables finding the fully qualified domain name (FQDN) of the computer using various techniques. The getHostNameWithDomain() and getHostNameWithoutDomain() try to provide reliable results in the various operating systems using hostname() and getDomainNameFromOs() and diverting to getLocalHostName() if they fail.

Constructor Summary

Constructors

Constructor and Description
OSUtil()

Method Summary

Modifier and Type	Method and Description
static String	exec(String command) Execute a command in the operating system using Runtime.exec and return the output as a string.
static String	exec(String command, int timeout, TimeUnit timeoutUnit) Execute a command in the operating system using Runtime.exec and return the output as a string.
static int	getDefaultExecTimeout()
static String	getDomainNameFromOs() Finds the DomainName from the operating system.
protected static List<String>	getHostNamesFromNetworkInterfaces(boolean includeIpAddresses, boolean includeIpv6) Enumerates the NetworkInterfaces and finds the HostNames defined for those by InetAddress.
static String	getHostNameWithDomain() The HostName of the computer in which the application is run, with the Domain part, i.e.
static String	getHostNameWithoutDomain() The HostName of the computer in which the application is run, without the Domain part.
static String	getLocalCanonicalHostName() CanonicalHostName from InetAddress.
static String	getLocalHostName() HostName from InetAddress.
static String	getOsName() The current Operating System.
static boolean	isAndroid()
static boolean	isLinux()
static boolean	isMacOs()
static boolean	isWindows()
static void	setDefaultExecTimeout(int defaultExecTimeout) Sets the default timeout for commands in seconds.

Methods inherited from class java.lang.Object

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

Constructor Detail

OSUtil

public OSUtil()

Method Detail

exec

public static String exec(String command)
                   throws IOException

Execute a command in the operating system using Runtime.exec and return the output as a string. Uses getDefaultExecTimeout().

Parameters:

command - the command to run

Returns:

output from the command, if it succeeds

Throws:

SecurityException - - If a security manager exists and its checkExec method doesn't allow creation of the subprocess

IOException - - If an I/O error occurs

CancellationException - - If the command doesn't return earlier than timeout or is interrupted

NullPointerException - - If command is null

exec

public static String exec(String command,
                          int timeout,
                          TimeUnit timeoutUnit)
                   throws IOException

Execute a command in the operating system using Runtime.exec and return the output as a string.

Parameters:

command - the command to run

timeout - the timeout for the command

timeoutUnit - unit for timeout

Returns:

output from the command, if it succeeds

Throws:

SecurityException - - If a security manager exists and its checkExec method doesn't allow creation of the subprocess

IOException - - If an I/O error occurs

CancellationException - - If the command doesn't return earlier than timeout or is interrupted

NullPointerException - - If command is null

getDefaultExecTimeout

public static int getDefaultExecTimeout()

getDomainNameFromOs

public static String getDomainNameFromOs()
                                  throws IOException

Finds the DomainName from the operating system.

• Windows - reads it from the registry
• Linux - reads it from 'hostname -d'
• MacOS - reads it from 'scutil --dns'

Otherwise, returns an empty string.

Returns:

the output of the command as explained above

Throws:

IOException - if the OS command execution fails

getHostNameWithDomain

public static String getHostNameWithDomain()

The HostName of the computer in which the application is run, with the Domain part, i.e. the fully qualified domain name (FQDN).

Returns:

the output of hostname(), except in Windows the Domain part is retrieved with getDomainNameFromOs() and added to the hostname(). If hostname() fails, returns getLocalHostName() instead.

getHostNameWithoutDomain

public static String getHostNameWithoutDomain()
                                       throws IOException

The HostName of the computer in which the application is run, without the Domain part.

Returns:

the result of hostname() without the domain part in any operating system.

Throws:

IOException - if hostName call fails respectively.

getLocalCanonicalHostName

public static String getLocalCanonicalHostName()

CanonicalHostName from InetAddress.

Returns:

the CanonicalHostName provided by 'java.net.InetAdress#getLocalHost()'

getLocalHostName

public static String getLocalHostName()

HostName from InetAddress.

Returns:

the HostName (other operating systems) provided by InetAddress.getLocalHost()

getOsName

public static String getOsName()

The current Operating System.

Returns:

Name of the Operating System as provided by 'System.getProperty("os.name")'

isAndroid

public static boolean isAndroid()

isLinux

public static boolean isLinux()

isMacOs

public static boolean isMacOs()

isWindows

public static boolean isWindows()

setDefaultExecTimeout

public static void setDefaultExecTimeout(int defaultExecTimeout)

Sets the default timeout for commands in seconds. By default 5 seconds.

getHostNamesFromNetworkInterfaces

protected static List<String> getHostNamesFromNetworkInterfaces(boolean includeIpAddresses,
                                                                boolean includeIpv6)

Enumerates the NetworkInterfaces and finds the HostNames defined for those by InetAddress.

Parameters:

includeIpAddresses - if true, also adds pure IP addresses in the list. Otherwise, only returns proper HostNames.

includeIpv6 - if true, also searches IPV6 addresses. Otherwise, returns only addresses for IPV4.

Returns:

The HostName of the first non-loopback or non-pointToPoint network interface.