com.zaxxer.nuprocess

Class NuProcessBuilder

java.lang.Object

com.zaxxer.nuprocess.NuProcessBuilder

public class NuProcessBuilder
extends Object

This class is used to create operating system processes.

Each NuProcessBuilder instance manages a collection of process attributes. The start() method creates a new NuProcess instance with those attributes. The start() method can be invoked repeatedly from the same instance to create new subprocesses with identical or related attributes.

Each NuProcessBuilder manages these attributes:

• a command, a list of strings which signifies the external program file to be invoked and its arguments, if any. Which string lists represent a valid operating system command is system-dependent. For example, it is common for each conceptual argument to be an element in this list, but there are operating systems where programs are expected to tokenize command line strings themselves - on such a system a Java implementation might require commands to contain exactly two elements.
• an environment, which is a system-dependent mapping from variables to values. The initial value is a copy of the environment of the current process. See System.getenv().

Modifying a process builder's attributes will affect processes subsequently started by that object's start() method, but will never affect previously started processes or the Java process itself.

Author:

Brett Wooldridge

Constructor Summary

Constructors

Constructor and Description
NuProcessBuilder(List<String> commands) Constructs a process builder with the specified operating system program and arguments.
NuProcessBuilder(List<String> commands, Map<String,String> environment) Constructs a process builder with the specified operating system program and arguments.
NuProcessBuilder(NuProcessHandler nuProcessHandler, List<String> commands) Constructs a process builder with the specified NuProcessHandler and operating system program and arguments.
NuProcessBuilder(NuProcessHandler nuProcessHandler, String... commands) Constructs a process builder with the specified NuProcessHandler and operating system program and arguments.
NuProcessBuilder(String... commands) Constructs a process builder with the specified operating system program and arguments.

Method Summary

Modifier and Type	Method and Description
List<String>	command() Get the List of commands that were used to construct this NuProcessBuilder.
Map<String,String>	environment() Returns a string map view of this process builder's environment.
void	setCwd(Path cwd) Set the Path to which the current working directory (cwd) of the subsequent launch of a NuProcess will be set when calling the start() method.
void	setProcessListener(NuProcessHandler listener) Set the NuProcessHandler instance that will be used for the next and subsequent launch of a NuProcess when calling the start() method.
NuProcess	start() Spawn the child process with the configured commands, environment, and NuProcessHandler.

Methods inherited from class java.lang.Object

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

Constructor Detail

NuProcessBuilder

public NuProcessBuilder(List<String> commands,
                        Map<String,String> environment)

Constructs a process builder with the specified operating system program and arguments. This constructor makes a copy of the command list. Invokers of this constructor must later call setProcessListener(NuProcessHandler) in order to set a NuProcessHandler instance.

Parameters:

commands - a List of commands

environment - The environment for the process

NuProcessBuilder

public NuProcessBuilder(List<String> commands)

Constructs a process builder with the specified operating system program and arguments. This constructor makes a copy of the command list. Invokers of this constructor must later call setProcessListener(NuProcessHandler) in order to set a NuProcessHandler instance.

Parameters:

commands - a List of commands

NuProcessBuilder

public NuProcessBuilder(String... commands)

Constructs a process builder with the specified operating system program and arguments. Invokers of this constructor must later call setProcessListener(NuProcessHandler) in order to set a NuProcessHandler instance.

Parameters:

commands - a list of commands

NuProcessBuilder

public NuProcessBuilder(NuProcessHandler nuProcessHandler,
                        String... commands)

Constructs a process builder with the specified NuProcessHandler and operating system program and arguments.

Parameters:

nuProcessHandler - a NuProcessHandler instance

commands - a list of commands

NuProcessBuilder

public NuProcessBuilder(NuProcessHandler nuProcessHandler,
                        List<String> commands)

Constructs a process builder with the specified NuProcessHandler and operating system program and arguments. This constructor makes a copy of the command list.

Parameters:

nuProcessHandler - a NuProcessHandler instance

commands - a List of commands

Method Detail

command

public List<String> command()

Get the List of commands that were used to construct this NuProcessBuilder.

Returns:

a List of commands

environment

public Map<String,String> environment()

Returns a string map view of this process builder's environment. Whenever a process builder is created, the environment is initialized to a copy of the current process environment. Subprocesses subsequently started by this object's start() method will use this map as their environment.

The returned object may be modified using ordinary Map operations prior to invoking the start() method. The returned map is typically case-sensitive on all platforms.

Returns:

This process builder's environment

setProcessListener

public void setProcessListener(NuProcessHandler listener)

Set the NuProcessHandler instance that will be used for the next and subsequent launch of a NuProcess when calling the start() method.

Parameters:

listener - a NuProcessHandler instance

setCwd

public void setCwd(Path cwd)

Set the Path to which the current working directory (cwd) of the subsequent launch of a NuProcess will be set when calling the start() method.

Parameters:

cwd - a Path to use for the process's current working directory, or null to disable setting the cwd of subsequently launched proceses

start

public NuProcess start()

Spawn the child process with the configured commands, environment, and NuProcessHandler.

Returns:

a NuProcess instance or null if there is an immediately detectable launch failure