Module org.refcodes.runtime

Package org.refcodes.runtime

Class Host

java.lang.Object

org.refcodes.runtime.Host

public final class Host
extends Object

The Host type abstracts the computer system on which this application runs on.

Method Summary

Modifier and Type	Method	Description
static String	exec(int aTimeoutMillis, String aCommandLine)	Executes a command and returns the output.
static String	exec(int aTimeoutMillis, String... aCommandLine)	Executes a command and returns the output.
static String	exec(String aCommandLine)	Executes a command and returns the output.
static String	exec(String... aCommandLine)	Executes a command and returns the output.
static String	getComputerName()	Determines the computer's name.
static Long	getPid()	Bad hack to get the JVM's (process TID) PID of the process running your JVM instance.
static String	getTempDir()	Determines the temporary directory for scratch space.
static String	getUname()	If on a *nix alike system, this method returns the output of the "uname -a" command: "uname" prints system information, "-a" instructs it to print all information.
static boolean	kill(Long aPid)	Bad hack to kill an OS thread by PID.
static Process	killProcess(long aPid)	Bad hack to kill an OS thread by PID.
static byte[]	toHostIpAddress()	Tries to determine a no-localhost IP-Address for this machine.
static byte[]	toHostMacAddress()	Tries to determine the host Mac-Address for this machine.
static String	toPrettySystemInfo()	Gathers all available system information from this Artifac's point of view.
static Map<String,String>	toSystemInfo()	Gathers all available system information from this Artifac's point of view.
static File	toUserWorkingDir()	Tries to determine the current directory from which the Java programm was started for example as of bash's pwd command.

Methods inherited from class java.lang.Object

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

Method Details

getComputerName

public static String getComputerName()

Determines the computer's name. First it tries to get it from the InetAddress, if it fails it tries to get it from the system's environment using the EnvironmentVariable.COMPUTERNAME (on Windows machines only) and if both fails, it returns the default Literal.LOCALHOST identifier.

Returns:

The computer's name, as fallback, Literal.LOCALHOST ("localhost") is returned.

getUname

public static String getUname()

If on a *nix alike system, this method returns the output of the "uname -a" command: "uname" prints system information, "-a" instructs it to print all information.

Returns:

The "uname -a" output or null if "uname" is not known.

exec

public static String exec(int aTimeoutMillis,
 String aCommandLine)
                   throws IOException,
InterruptedException

Executes a command and returns the output.

Parameters:

aTimeoutMillis - The time in milliseconds to wait till the process is killed when not terminated yet.

aCommandLine - the command

Returns:

Null if execution failed, else the according output. An empty String stands fur successful execution.

Throws:

IOException - in case there were problems executing the command.

InterruptedException - thrown in case execution as been interrupted.

exec

public static String exec(int aTimeoutMillis,
 String... aCommandLine)
                   throws IOException,
InterruptedException

Executes a command and returns the output.

Parameters:

aTimeoutMillis - The time in milliseconds to wait till the process is killed when not terminated yet.

aCommandLine - the command with the arguments to be passed to the command.

Returns:

Null if execution failed, else the according output. An empty String stands fur successful execution.

Throws:

IOException - in case there were problems executing the command.

InterruptedException - thrown in case execution as been interrupted.

exec

public static String exec(String aCommandLine)
                   throws IOException

Executes a command and returns the output.

Parameters:

aCommandLine - the command

Returns:

Null if execution failed, else the according output. An empty String stands fur successful execution.

Throws:

IOException - in case there were problems executing the command.

exec

public static String exec(String... aCommandLine)
                   throws IOException

Executes a command and returns the output.

Parameters:

aCommandLine - the command with the arguments to be passed to the command.

Returns:

Null if execution failed, else the according output. An empty String stands fur successful execution.

Throws:

IOException - in case there were problems executing the command.

toSystemInfo

public static Map<String,String> toSystemInfo()

Gathers all available system information from this Artifac's point of view.

Returns:

A Map containing the available information being gathered.

getTempDir

public static String getTempDir()

Determines the temporary directory for scratch space.

Returns:

The according temporary directory.

toPrettySystemInfo

public static String toPrettySystemInfo()

Gathers all available system information from this Artifac's point of view. This method may rely on the output of toSystemInfo().

Returns:

A String containing the available information being gathered.

toHostIpAddress

public static byte[] toHostIpAddress()
                              throws SocketException,
UnknownHostException

Tries to determine a no-localhost IP-Address for this machine. The best guess is returned. If none no-localhost address is found, then the localhost's IP-Address may be returned (as of InetAddress.getLocalHost()).

Returns:

The best guest for a no-localhost IP-Address or as a fall back the localhost's IP-Address (as of InetAddress.getLocalHost() may be returned.

Throws:

SocketException - Thrown to indicate that accessing the network interfaces caused a problem.

UnknownHostException - Thrown to indicate that the IP address of the local host could not be determined.

toHostMacAddress

public static byte[] toHostMacAddress()
                               throws SocketException,
UnknownHostException

Tries to determine the host Mac-Address for this machine. The best guess is returned.

Returns:

The best guest for a Mac-Address is returned.

Throws:

SocketException - Thrown to indicate that accessing the network interfaces caused a problem.

UnknownHostException - Thrown to indicate that the IP address of the local host could not be determined.

getPid

public static Long getPid()

Bad hack to get the JVM's (process TID) PID of the process running your JVM instance.

Returns:

The PID (process TID) of the JVM running your thread.

See Also:

• "http://stackoverflow.com/questions/35842/how-can-a-java-program-get-its-own-process-id"

killProcess

public static Process killProcess(long aPid)
                           throws IOException

Bad hack to kill an OS thread by PID. The current threads does not wait till the operation finished.

Parameters:

aPid - The process TID (PID) of the process to kill.

Returns:

The Process object representing the kill operation. This instance will let you wait till the operation finished Process.waitFor() and provides access to the Process.exitValue()

Throws:

IOException - Thrown in case of failing to successfully execute the kill operation.

See Also:

• "http://stackoverflow.com/questions/9573696/kill-a-process-based-on-pid-in-java"
• "http://stackoverflow.com/questions/2950338/how-can-i-kill-a-linux-process-in-java-with-sigkill-process-destroy-does-sigte"

kill

public static boolean kill(Long aPid)
                    throws IOException,
InterruptedException

Bad hack to kill an OS thread by PID. The current threads does wait till the operation finished.

Parameters:

aPid - The process TID (PID) of the process to kill.

Returns:

True in case killing the process was successful (e.g. the kill operation returned an exit code 0), else false.

Throws:

IOException - Thrown in case of failing to successfully execute the kill operation.

InterruptedException - the interrupted exception

See Also:

• "http://stackoverflow.com/questions/9573696/kill-a-process-based-on-pid-in-java"
• "http://stackoverflow.com/questions/2950338/how-can-i-kill-a-linux-process-in-java-with-sigkill-process-destroy-does-sigte"

toUserWorkingDir

public static File toUserWorkingDir()

Tries to determine the current directory from which the Java programm was started for example as of bash's pwd command. Pass as JVM argument via "-Dcurrent.dir=/path/to/current/dir".

Returns:

The current path of the user invoking the Java programm or null if the current path cannot be determined.