org.apache.tools.ant.taskdefs

Class Execute


public class Execute
extends java.lang.Object

Runs an external program.
Since:
Ant 1.2

Field Summary

static int
INVALID
Invalid exit code.

Constructor Summary

Execute()
Creates a new execute object using PumpStreamHandler for stream handling.
Execute(ExecuteStreamHandler streamHandler)
Creates a new execute object.
Execute(ExecuteStreamHandler streamHandler, ExecuteWatchdog watchdog)
Creates a new execute object.

Method Summary

static void
closeStreams(Process process)
Close the streams belonging to the given Process.
int
execute()
Runs a process defined by the command line and returns its exit status.
String[]
getCommandline()
Returns the commandline used to create a subprocess.
String[]
getEnvironment()
Returns the environment used to create a subprocess.
int
getExitValue()
Query the exit value of the process.
static Vector
getProcEnvironment()
Find the list of environment variables for this process.
File
getWorkingDirectory()
Return the working directory.
boolean
isFailure()
Did this execute return in a failure.
static boolean
isFailure(int exitValue)
Checks whether exitValue signals a failure on the current system (OS specific).
boolean
killedProcess()
Test for an untimely death of the process.
static Process
launch(Project project, String[] command, String[] env, File dir, boolean useVM)
Creates a process that runs a command.
static void
runCommand(Task task, String[] cmdline)
A utility method that runs an external command.
void
setAntRun(Project project)
Set the name of the antRun script using the project's value.
void
setCommandline(String[] commandline)
Sets the commandline of the subprocess to launch.
void
setEnvironment(String[] env)
Sets the environment variables for the subprocess to launch.
protected void
setExitValue(int value)
Set the exit value.
void
setNewenvironment(boolean newenv)
Set whether to propagate the default environment or not.
void
setSpawn(boolean spawn)
Set whether or not you want the process to be spawned.
void
setStreamHandler(ExecuteStreamHandler streamHandler)
Set the stream handler to use.
void
setVMLauncher(boolean useVMLauncher)
Launch this execution through the VM, where possible, rather than through the OS's shell.
void
setWorkingDirectory(File wd)
Sets the working directory of the process to execute.
void
spawn()
Starts a process defined by the command line.
static String
toString(ByteArrayOutputStream bos)
ByteArrayOutputStream#toString doesn't seem to work reliably on OS/390, at least not the way we use it in the execution context.
protected void
waitFor(Process process)
Wait for a given process.

Field Details

INVALID

public static final int INVALID
Invalid exit code. set to Integer.MAX_VALUE

Constructor Details

Execute

public Execute()
Creates a new execute object using PumpStreamHandler for stream handling.

Execute

public Execute(ExecuteStreamHandler streamHandler)
Creates a new execute object.
Parameters:
streamHandler - the stream handler used to handle the input and output streams of the subprocess.

Execute

public Execute(ExecuteStreamHandler streamHandler,
               ExecuteWatchdog watchdog)
Creates a new execute object.
Parameters:
streamHandler - the stream handler used to handle the input and output streams of the subprocess.
watchdog - a watchdog for the subprocess or null to to disable a timeout for the subprocess.

Method Details

closeStreams

public static void closeStreams(Process process)
Close the streams belonging to the given Process.
Parameters:
process - the Process.

execute

public int execute()
            throws IOException
Runs a process defined by the command line and returns its exit status.
Returns:
the exit status of the subprocess or INVALID.

getCommandline

public String[] getCommandline()
Returns the commandline used to create a subprocess.
Returns:
the commandline used to create a subprocess.

getEnvironment

public String[] getEnvironment()
Returns the environment used to create a subprocess.
Returns:
the environment used to create a subprocess.

getExitValue

public int getExitValue()
Query the exit value of the process.
Returns:
the exit value or Execute.INVALID if no exit value has been received.

getProcEnvironment

public static Vector getProcEnvironment()
Find the list of environment variables for this process.
Returns:
a vector containing the environment variables. The vector elements are strings formatted like variable = value.

getWorkingDirectory

public File getWorkingDirectory()
Return the working directory.
Returns:
the directory as a File.
Since:
Ant 1.7

isFailure

public boolean isFailure()
Did this execute return in a failure.
Returns:
true if and only if the exit code is interpreted as a failure
Since:
Ant1.7

isFailure

public static boolean isFailure(int exitValue)
Checks whether exitValue signals a failure on the current system (OS specific).

Note that this method relies on the conventions of the OS, it will return false results if the application you are running doesn't follow these conventions. One notable exception is the Java VM provided by HP for OpenVMS - it will return 0 if successful (like on any other platform), but this signals a failure on OpenVMS. So if you execute a new Java VM on OpenVMS, you cannot trust this method.

Parameters:
exitValue - the exit value (return code) to be checked.
Returns:
true if exitValue signals a failure.

killedProcess

public boolean killedProcess()
Test for an untimely death of the process.
Returns:
true if a watchdog had to kill the process.
Since:
Ant 1.5

launch

public static Process launch(Project project,
                             String[] command,
                             String[] env,
                             File dir,
                             boolean useVM)
            throws IOException
Creates a process that runs a command.
Parameters:
project - the Project, only used for logging purposes, may be null.
command - the command to run.
env - the environment for the command.
dir - the working directory for the command.
useVM - use the built-in exec command for JDK 1.3 if available.
Returns:
the process started.
Since:
Ant 1.5

runCommand

public static void runCommand(Task task,
                              String[] cmdline)
            throws BuildException
A utility method that runs an external command. Writes the output and error streams of the command to the project log.
Parameters:
task - The task that the command is part of. Used for logging
cmdline - The command to execute.
Throws:
BuildException - if the command does not exit successfully.

setAntRun

public void setAntRun(Project project)
            throws BuildException
Set the name of the antRun script using the project's value.
Parameters:
project - the current project.
Throws:
BuildException - not clear when it is going to throw an exception, but it is the method's signature.

setCommandline

public void setCommandline(String[] commandline)
Sets the commandline of the subprocess to launch.
Parameters:
commandline - the commandline of the subprocess to launch.

setEnvironment

public void setEnvironment(String[] env)
Sets the environment variables for the subprocess to launch.
Parameters:
env - array of Strings, each element of which has an environment variable settings in format key=value.

setExitValue

protected void setExitValue(int value)
Set the exit value.
Parameters:
value - exit value of the process.

setNewenvironment

public void setNewenvironment(boolean newenv)
Set whether to propagate the default environment or not.
Parameters:
newenv - whether to propagate the process environment.

setSpawn

public void setSpawn(boolean spawn)
Set whether or not you want the process to be spawned. Default is not spawned.
Parameters:
spawn - if true you do not want Ant to wait for the end of the process.
Since:
Ant 1.6

setStreamHandler

public void setStreamHandler(ExecuteStreamHandler streamHandler)
Set the stream handler to use.
Parameters:
streamHandler - ExecuteStreamHandler.
Since:
Ant 1.6

setVMLauncher

public void setVMLauncher(boolean useVMLauncher)
Launch this execution through the VM, where possible, rather than through the OS's shell. In some cases and operating systems using the shell will allow the shell to perform additional processing such as associating an executable with a script, etc.
Parameters:
useVMLauncher - true if exec should launch through the VM, false if the shell should be used to launch the command.

setWorkingDirectory

public void setWorkingDirectory(File wd)
Sets the working directory of the process to execute.

This is emulated using the antRun scripts unless the OS is Windows NT in which case a cmd.exe is spawned, or MRJ and setting user.dir works, or JDK 1.3 and there is official support in java.lang.Runtime.

Parameters:
wd - the working directory of the process.

spawn

public void spawn()
            throws IOException
Starts a process defined by the command line. Ant will not wait for this process, nor log its output.
Since:
Ant 1.6

toString

public static String toString(ByteArrayOutputStream bos)
ByteArrayOutputStream#toString doesn't seem to work reliably on OS/390, at least not the way we use it in the execution context.
Parameters:
bos - the output stream that one wants to read.
Returns:
the output stream as a string, read with special encodings in the case of z/os and os/400.
Since:
Ant 1.5

waitFor

protected void waitFor(Process process)
Wait for a given process.
Parameters:
process - the process one wants to wait for.