Package com.linkedin.alpini.io

Class ExternalCommand

java.lang.Object

com.linkedin.alpini.io.ExternalCommand

public class ExternalCommand
extends java.lang.Object

This class encapsulates a java Process to handle properly output and error and preventing potential deadlocks. The idea is that the command is executed and you can get the error or output. Simple to use. Should not be used for big outputs because they are buffered internally.

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	JDK_HOME_DIR
static org.apache.logging.log4j.Logger	LOG
static java.lang.String	MODULE

Constructor Summary

Constructors

Constructor	Description
ExternalCommand(java.lang.ProcessBuilder processBuilder)	Constructor

Method Summary

Modifier and Type	Method	Description
static ExternalCommand	create(java.lang.String... commands)	Creates an external process from the command.
static ExternalCommand	create(java.util.List<java.lang.String> commands)	Creates an external process from the command.
void	destroy()
static ExternalCommand	execute(java.io.File workingDirectory, java.lang.String command, java.lang.String... args)	Executes the external command in the given working directory and waits for it to be finished.
static ExternalCommand	executeWithTimeout(java.io.File workingDirectory, java.lang.String command, long timeout, java.lang.String... args)	Executes the external command in the given working directory and waits (until timeout is elapsed) for it to be finished.
static ExternalCommand	executeWithTimeoutWithEnv(java.io.File workingDirectory, java.lang.String command, long timeout, java.util.Map<java.lang.String,java.lang.String> env, java.lang.String... args)
int	exitValue()
java.util.Map<java.lang.String,java.lang.String>	getEnvironment()
byte[]	getError()
byte[]	getOutput()
boolean	getRedirectErrorStream()
java.lang.String	getStringError()	Returns the error as a string.
java.lang.String	getStringError(java.lang.String encoding)	Returns the error as a string.
java.lang.String	getStringError(java.nio.charset.Charset encoding)	Returns the error as a string.
java.lang.String	getStringOutput()	Returns the output as a string.
java.lang.String	getStringOutput(java.lang.String encoding)	Returns the output as a string.
java.lang.String	getStringOutput(java.nio.charset.Charset encoding)	Returns the output as a string.
java.io.File	getWorkingDirectory()
boolean	isTimedOut()
void	setRedirectErrorStream(boolean redirectErrorStream)
void	setTimedOut(boolean val)
void	setWorkingDirectory(java.io.File directory)
void	start()	After creating the command, you have to start it...
static ExternalCommand	start(java.lang.String... commands)	Creates an external process from the command.
int	waitFor()	Properly waits until everything is complete: joins on the thread that reads the output, joins on the thread that reads the error and finally wait for the process to be finished.
int	waitFor(long timeout)	Properly waits until everything is complete: joins on the thread that reads the output, joins on the thread that reads the error and finally wait for the process to be finished.
int	waitFor(long timeout, java.util.concurrent.TimeUnit unit)	Properly waits until everything is complete: joins on the thread that reads the output, joins on the thread that reads the error and finally wait for the process to be finished.

Methods inherited from class java.lang.Object

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

Field Detail

JDK_HOME_DIR

public static final java.lang.String JDK_HOME_DIR

MODULE

public static final java.lang.String MODULE

LOG

public static final org.apache.logging.log4j.Logger LOG

Constructor Detail

ExternalCommand

public ExternalCommand(java.lang.ProcessBuilder processBuilder)

Constructor

Method Detail

start

public void start()
           throws java.io.IOException

After creating the command, you have to start it...

Throws:

java.io.IOException

getEnvironment

public java.util.Map<java.lang.String,java.lang.String> getEnvironment()

See Also:

ProcessBuilder

getWorkingDirectory

public java.io.File getWorkingDirectory()

See Also:

ProcessBuilder

setWorkingDirectory

public void setWorkingDirectory(java.io.File directory)

See Also:

ProcessBuilder

getRedirectErrorStream

public boolean getRedirectErrorStream()

See Also:

ProcessBuilder

setRedirectErrorStream

public void setRedirectErrorStream(boolean redirectErrorStream)

See Also:

ProcessBuilder

setTimedOut

public void setTimedOut(boolean val)

isTimedOut

public boolean isTimedOut()

getOutput

public byte[] getOutput()
                 throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

getError

public byte[] getError()
                throws java.lang.InterruptedException

Throws:

java.lang.InterruptedException

getStringOutput

public java.lang.String getStringOutput(java.lang.String encoding)
                                 throws java.lang.InterruptedException,
                                        java.io.UnsupportedEncodingException

Returns the output as a string.

Parameters:

encoding -

Returns:

encoded string

Throws:

java.lang.InterruptedException

java.io.UnsupportedEncodingException

getStringOutput

public java.lang.String getStringOutput(java.nio.charset.Charset encoding)
                                 throws java.lang.InterruptedException

Returns the output as a string.

Parameters:

encoding -

Returns:

encoded string

Throws:

java.lang.InterruptedException

java.io.UnsupportedEncodingException

getStringOutput

public java.lang.String getStringOutput()
                                 throws java.lang.InterruptedException

Returns the output as a string. Uses encoding "UTF-8".

Returns:

utf8 encoded string

Throws:

java.lang.InterruptedException

getStringError

public java.lang.String getStringError(java.nio.charset.Charset encoding)
                                throws java.lang.InterruptedException

Returns the error as a string.

Parameters:

encoding -

Returns:

error as string

Throws:

java.lang.InterruptedException

getStringError

public java.lang.String getStringError(java.lang.String encoding)
                                throws java.lang.InterruptedException,
                                       java.io.UnsupportedEncodingException

Returns the error as a string.

Parameters:

encoding -

Returns:

error as string

Throws:

java.lang.InterruptedException

java.io.UnsupportedEncodingException

getStringError

public java.lang.String getStringError()
                                throws java.lang.InterruptedException

Returns the error as a string. Uses encoding "UTF-8".

Returns:

error as string

Throws:

java.lang.InterruptedException

waitFor

public int waitFor()
            throws java.lang.InterruptedException

Properly waits until everything is complete: joins on the thread that reads the output, joins on the thread that reads the error and finally wait for the process to be finished.

Returns:

the status code of the process.

Throws:

java.lang.InterruptedException

waitFor

public int waitFor(long timeout,
                   java.util.concurrent.TimeUnit unit)
            throws java.lang.InterruptedException,
                   java.util.concurrent.TimeoutException,
                   java.io.IOException

Properly waits until everything is complete: joins on the thread that reads the output, joins on the thread that reads the error and finally wait for the process to be finished. If the process has not completed before the timeout, throws a TimeoutException

Returns:

the status code of the process.

Throws:

java.util.concurrent.TimeoutException

java.lang.InterruptedException

java.io.IOException

waitFor

public int waitFor(long timeout)
            throws java.lang.InterruptedException,
                   java.util.concurrent.TimeoutException,
                   java.io.IOException

Properly waits until everything is complete: joins on the thread that reads the output, joins on the thread that reads the error and finally wait for the process to be finished. If the process has not completed before the timeout, throws a TimeoutException

Returns:

the status code of the process.

Throws:

java.util.concurrent.TimeoutException

java.lang.InterruptedException

java.io.IOException

exitValue

public int exitValue()

destroy

public void destroy()

create

public static ExternalCommand create(java.lang.String... commands)

Creates an external process from the command. It is not started and you have to call start on it!

Parameters:

commands - the command to execute

Returns:

the process

create

public static ExternalCommand create(java.util.List<java.lang.String> commands)

Creates an external process from the command. It is not started and you have to call start on it!

Parameters:

commands - the command to execute

Returns:

the process

start

@CheckReturnValue
public static ExternalCommand start(java.lang.String... commands)
                             throws java.io.IOException

Creates an external process from the command. The command is executed.

Parameters:

commands - the commands to execute

Returns:

the process

Throws:

java.io.IOException - if there is an error

execute

@CheckReturnValue
public static ExternalCommand execute(java.io.File workingDirectory,
                                      java.lang.String command,
                                      java.lang.String... args)
                               throws java.io.IOException,
                                      java.lang.InterruptedException

Executes the external command in the given working directory and waits for it to be finished.

Parameters:

workingDirectory - the root directory from where to run the command

command - the command to execute (should be relative to the working directory

args - the arguments to the command

Returns:

the process

Throws:

java.io.IOException

java.lang.InterruptedException

executeWithTimeout

@CheckReturnValue
public static ExternalCommand executeWithTimeout(java.io.File workingDirectory,
                                                 java.lang.String command,
                                                 long timeout,
                                                 java.lang.String... args)
                                          throws java.io.IOException,
                                                 java.lang.InterruptedException

Executes the external command in the given working directory and waits (until timeout is elapsed) for it to be finished.

Parameters:

workingDirectory - the root directory from where to run the command

command - the command to execute (should be relative to the working directory

timeout - the maximum amount of time to wait for this external command (in ms). If this value is less than or equal to 0, timeout is ignored

args - the arguments to the command

Returns:

the process

Throws:

java.io.IOException

java.lang.InterruptedException

executeWithTimeoutWithEnv

@CheckReturnValue
public static ExternalCommand executeWithTimeoutWithEnv(java.io.File workingDirectory,
                                                        java.lang.String command,
                                                        long timeout,
                                                        java.util.Map<java.lang.String,java.lang.String> env,
                                                        java.lang.String... args)
                                                 throws java.io.IOException,
                                                        java.lang.InterruptedException

Throws:

java.io.IOException

java.lang.InterruptedException