Package de.iip_ecosphere.platform.services.environment

Class ProcessSupport

java.lang.Object

de.iip_ecosphere.platform.services.environment.ProcessSupport

public class ProcessSupport
extends Object

Process execution support functions. Process scripts or binaries shall be packaged using a Maven assembly descriptor into a ZIP file in the "root" of the Jar/Service artifact (fallback for testing can be defined, e.g., src/main/python/...). Here, the name is free, but shall not collide with the default process artifacts of generated services.

Author:

Holger Eichelberger, SSE

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ProcessSupport.ScriptOwner	Holds the script context.

Field Summary

Fields

Modifier and Type	Field	Description
static final Consumer<ProcessBuilder>	INHERIT_IO	A simple default customizer always requesting to inherit the process IO (standard in/out/err).

Constructor Summary

Constructors

Constructor	Description
ProcessSupport()

Method Summary

Modifier and Type	Method	Description
static void	callPython(ProcessSupport.ScriptOwner owner, String script, Consumer<String> cmdResult, String... args)	Call python scripts, waiting for and killing finally.
static int	callPythonWaitForAndKill(File dir, String script, Consumer<String> cmdResult, String resultFile, Consumer<ProcessBuilder> cust, String... args)	Call python, wait for ending and kill it if needed.
static Process	createPythonProcess(File dir, String script, Consumer<ProcessBuilder> procCustomizer, String... args)	Creates and starts a Python process.
static int	waitForAndKill(Process proc, String script, Consumer<String> cmdResult, String resultFile)	Wait for a (scripted) process until it is really dead.

Methods inherited from class java.lang.Object

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

Field Details

INHERIT_IO

public static final Consumer<ProcessBuilder> INHERIT_IO

A simple default customizer always requesting to inherit the process IO (standard in/out/err). May particularly be helpful for debugging.

Constructor Details

ProcessSupport

public ProcessSupport()

Method Details

callPython

public static void callPython(ProcessSupport.ScriptOwner owner,
 String script,
 Consumer<String> cmdResult,
 String... args)

Call python scripts, waiting for and killing finally. Scripts shall be located in a Maven packaged ZIP represented by owner (including unpacking state).

Parameters:

owner - the script owner and data instance

script - the script file name to execute in the context of owner

cmdResult - a consumer for the result, may be null for none

args - the process arguments for the script including python arguments (first), script and script arguments

createPythonProcess

public static Process createPythonProcess(File dir,
 String script,
 Consumer<ProcessBuilder> procCustomizer,
 String... args)
                                   throws IOException

Creates and starts a Python process.

Parameters:

dir - the home dir where to find the script/run it within

script - the script to execute

procCustomizer - allows to customize the internal process builder, may be null for none

args - the process arguments for the script including python arguments (first), script and script arguments

Returns:

the created process

Throws:

IOException - if process creation fails

waitForAndKill

public static int waitForAndKill(Process proc,
 String script,
 Consumer<String> cmdResult,
 String resultFile)

Wait for a (scripted) process until it is really dead.

Parameters:

proc - the process to wait for

script - the script name for logging

cmdResult - a consumer for the result, may be null for none

resultFile - file to read result from, e.g., short lived processes, if null use standard in

Returns:

the process status, -1 if the process was not executed

See Also:

• AbstractProcessService.redirectIO(InputStream, PrintStream)

callPythonWaitForAndKill

public static int callPythonWaitForAndKill(File dir,
 String script,
 Consumer<String> cmdResult,
 String resultFile,
 Consumer<ProcessBuilder> cust,
 String... args)

Call python, wait for ending and kill it if needed. Catch all exceptions.

Parameters:

dir - the home dir where to find the script/run it within

script - the script to execute

cmdResult - a consumer for the result, may be null for none

resultFile - file to read result from, e.g., short lived processes, if null use standard in

cust - optional process customizer, may be null for none

args - the process arguments for the script including python arguments (first), script and script arguments

Returns:

the process status, -1 if the process was not executed

See Also:

• createPythonProcess(File, String, Consumer, String...)
• waitForAndKill(Process, String, Consumer, String)