Java The Complete Reference, Seventh Edition

408 Part II: The Java Library

To create a process usingProcessBuilder, simply create an instance ofProcessBuilder,

specifying the name of the program and any needed arguments. To begin execution of the

program, callstart( )on that instance. Here is an example that executes the Windows text

editornotepad. Notice that it specifies the name of the file to edit as an argument.

class PBDemo {

public static void main(String args[]) {

try {

ProcessBuilder proc =

new ProcessBuilder("notepad.exe", "testfile");

proc.start();

} catch (Exception e) {

System.out.println("Error executing notepad.");

}

}

}

Method Description

List<String> command( ) Returns a reference to aListthat contains the

name of the program and its arguments. Changes

to this list affect the invoking process.

ProcessBuilder command(List<String>args) Sets the name of the program and its arguments

to those specified byargs.Changes to this list

affect the invoking process. Returns a reference to

the invoking object.

ProcessBuilder command(String ...args) Sets the name of the program and its arguments

to those specified byargs.Returns a reference to

the invoking object.

File director y( ) Returns the current working director y of the invoking

object. This value will benullif the director y is the

same as that of the Java program that started the

process.

ProcessBuilder director y(Filedir) Sets the current working director y of the invoking

object. Returns a reference to the invoking object.

Map<String, String> environment( ) Returns the environmental variables associated

with the invoking object as key/value pairs.

boolean redirectErrorStream( ) Returnstrueif the standard error stream has been

redirected to the standard output stream. Returns

falseif the streams are separate.

ProcessBuilder

redirectErrorStream(booleanmerge)

Ifmergeistrue, then the standard error stream is

redirected to standard output. Ifmergeisfalse,

the streams are separated, which is the default

state. Returns a reference to the invoking object.

Process start( )

throws IOException

Begins the process specified by the invoking object.

In other words, it runs the specified program.

TABLE 16-12 The Methods Defined byProcessBuilder