org.apache.commons.launcher

Class LaunchTask

public class LaunchTask extends Task

A class that eliminates the need for a batch or shell script to launch a Java class. Some situations where elimination of a batch or shell script may be desirable are:

Author: Patrick Luby

Field Summary
static StringARG_PROP_NAME
The argument property name.
static StringTASK_NAME
The name of this task.
Method Summary
voidaddArg(ConditionalArgument arg)
Add a nested arg element.
voidaddArgset(ArgumentSet set)
Add a nested argset element.
voidaddJvmarg(ConditionalArgument jvmArg)
Add a nested jvmarg element.
voidaddJvmargset(JVMArgumentSet set)
Add a nested jvmargset element.
voidaddSysproperty(ConditionalVariable var)
Add a nested sysproperty element.
voidaddSyspropertyset(SysPropertySet set)
Add a nested syspropertyset element.
PathcreateClasspath()
Create a nested classpath element.
PathcreateFilterclasspath()
Create a nested filter classpath element.
voidexecute()
Construct a Java command and execute it using the settings that Ant parsed from the Launcher's XML file.
static Process[]getChildProcesses()
Get the synchronous child processes for all instances of this class.
voidsetAppendoutput(boolean appendOutput)
Set the appendOutput flag.
voidsetClassname(String mainClassName)
Set the class name.
voidsetClasspath(Path classpath)
Set the classpath.
voidsetClasspathref(Reference ref)
Adds a reference to a classpath defined elsewhere.
voidsetDebug(boolean debug)
Set the debug flag.
voidsetDisplayminimizedwindow(boolean displayMinimizedWindow)
Set the displayMinimizedWindow flag.
voidsetDisposeminimizedwindow(boolean disposeMinimizedWindow)
Set the disposeMinimizedWindow flag.
voidsetFailonerror(boolean failOnError)
Set the failOnError flag.
voidsetFilterclassname(String filterClassName)
Set the filter class name.
voidsetFilterclasspath(Path filterClasspath)
Set the filter class' classpath.
voidsetMinimizedwindowicon(File minimizedWindowIcon)
Set the icon file for the minimized window that will be displayed in the Windows taskbar.
voidsetMinimizedwindowtitle(String minimizedWindowTitle)
Set the title for the minimized window that will be displayed in the Windows taskbar.
voidsetOutput(File outputFile)
Set the file that the child JVM's System.out and System.err will be redirected to.
voidsetPrint(boolean print)
Set the print flag.
voidsetRedirectoutput(boolean redirect)
Set the redirect flag.
voidsetRequiretools(boolean requireTools)
Set the requireTools flag.
voidsetUseargs(boolean useArgs)
Set the useArgs flag.
voidsetUsesystemin(boolean useSystemIn)
Set the useSystemIn flag.
voidsetWaitforchild(boolean waitForChild)
Set the waitForChild flag.

Field Detail

ARG_PROP_NAME

public static final String ARG_PROP_NAME
The argument property name.

TASK_NAME

public static final String TASK_NAME
The name of this task.

Method Detail

addArg

public void addArg(ConditionalArgument arg)
Add a nested arg element. Note that Ant will not invoke the specified arg object's setter methods until after Ant invokes this method so processing of the specified arg object is handled in the execute method.

Parameters: arg the arg element

addArgset

public void addArgset(ArgumentSet set)
Add a nested argset element.

Parameters: set the argset element

addJvmarg

public void addJvmarg(ConditionalArgument jvmArg)
Add a nested jvmarg element. Note that Ant will not invoke the specified jvmarg object's setter methods until after Ant invokes this method so processing of the specified jvmarg object is handled in the execute method.

Parameters: jvmArg the jvmarg element

addJvmargset

public void addJvmargset(JVMArgumentSet set)
Add a nested jvmargset element.

Parameters: set the jvmargset element

addSysproperty

public void addSysproperty(ConditionalVariable var)
Add a nested sysproperty element. Note that Ant will not invoke the specified sysproperty object's setter methods until after Ant invokes this method so processing of the specified sysproperty object is handled in the execute method.

Parameters: var the sysproperty element

addSyspropertyset

public void addSyspropertyset(SysPropertySet set)
Add a nested syspropertyset element.

Parameters: set the syspropertyset element

createClasspath

public Path createClasspath()
Create a nested classpath element.

Returns: the Path object that contains all nested classpath elements

createFilterclasspath

public Path createFilterclasspath()
Create a nested filter classpath element.

Returns: the Path object that contains all nested filter classpath elements

execute

public void execute()
Construct a Java command and execute it using the settings that Ant parsed from the Launcher's XML file. This method is called by the Ant classes.

Throws: BuildException if there is a configuration or other error

getChildProcesses

public static Process[] getChildProcesses()
Get the synchronous child processes for all instances of this class.

Returns: the instances of this class.

setAppendoutput

public void setAppendoutput(boolean appendOutput)
Set the appendOutput flag. Setting this flag to true will cause the child JVM to append System.out and System.err to the file specified by the setOutput method. Setting this flag to false will cause the child to overwrite the file.

Parameters: appendOutput true if output should be appended to the output file

setClassname

public void setClassname(String mainClassName)
Set the class name.

Parameters: mainClassName the class to execute main(String[])

setClasspath

public void setClasspath(Path classpath)
Set the classpath.

Parameters: classpath the classpath

setClasspathref

public void setClasspathref(Reference ref)
Adds a reference to a classpath defined elsewhere.

Parameters: ref reference to the classpath

setDebug

public void setDebug(boolean debug)
Set the debug flag. Setting this flag to true will cause this task to run the child JVM using the JDB debugger.

Parameters: debug the debug flag

setDisplayminimizedwindow

public void setDisplayminimizedwindow(boolean displayMinimizedWindow)
Set the displayMinimizedWindow flag. Note that this flag has no effect on non-Windows platforms. On Windows platform, setting this flag to true will cause a minimized window to be displayed in the Windows task bar while the child process is executing. This flag is usually set to true for server applications that also have their "waitForChild" attribute set to false via the LaunchTask method.

Parameters: displayMinimizedWindow true if a minimized window should be displayed in the Windows task bar while the child process is executing

setDisposeminimizedwindow

public void setDisposeminimizedwindow(boolean disposeMinimizedWindow)
Set the disposeMinimizedWindow flag. Note that this flag has no effect on non-Windows platforms. On Windows platform, setting this flag to true will cause any minimized window that is display by setting the "displayMinimizedWindow" attribute to true via the LaunchTask to be automatically disposed of when the child JVM's main(String[]) returns. This flag is normally used for applications that don't explicitly call System#exit(int). If an application does not explicitly call System#exit(int), an minimized windows need to be disposed of for the child JVM to exit.

Parameters: disposeMinimizedWindow true if a minimized window in the Windows taskbar should be automatically disposed of after the child JVM's main(String[]) returns

setFailonerror

public void setFailonerror(boolean failOnError)
Set the failOnError flag.

Parameters: failOnError true if the launch process should stop if the child JVM returns an exit value other than 0

setFilterclassname

public void setFilterclassname(String filterClassName)
Set the filter class name.

Parameters: filterClassName the class that implements the LaunchFilter interface

setFilterclasspath

public void setFilterclasspath(Path filterClasspath)
Set the filter class' classpath.

Parameters: classpath the classpath for the filter class

setMinimizedwindowicon

public void setMinimizedwindowicon(File minimizedWindowIcon)
Set the icon file for the minimized window that will be displayed in the Windows taskbar. Note that this property has no effect on non-Windows platforms.

Parameters: minimizedWindowIcon the icon file to use for any minimized window that is displayed in the Windows taskbar

setMinimizedwindowtitle

public void setMinimizedwindowtitle(String minimizedWindowTitle)
Set the title for the minimized window that will be displayed in the Windows taskbar. Note that this property has no effect on non-Windows platforms.

Parameters: minimizedWindowTitle the title to set for any minimized window that is displayed in the Windows taskbar

setOutput

public void setOutput(File outputFile)
Set the file that the child JVM's System.out and System.err will be redirected to. Output will only be redirected if the redirect flag is set to true via the LaunchTask method.

Parameters: outputFile a File to redirect System.out and System.err to

setPrint

public void setPrint(boolean print)
Set the print flag. Setting this flag to true will cause the full child JVM command to be printed to System#out.

Parameters: print the print flag

setRedirectoutput

public void setRedirectoutput(boolean redirect)
Set the redirect flag. Setting this flag to true will cause the child JVM's System.out and System.err to be redirected to file set using the setOutput method. Setting this flag to false will cause no redirection.

Parameters: redirect true if System.out and System.err should be redirected

setRequiretools

public void setRequiretools(boolean requireTools)
Set the requireTools flag. Setting this flag to true will cause the JVM's tools.jar to be added to the child JVM's classpath. This sets an explicit requirement that the user use a JDK instead of a JRE. Setting this flag to false explicitly allows the user to use a JRE.

Parameters: redirect true if a JDK is required and false if only a JRE is required

setUseargs

public void setUseargs(boolean useArgs)
Set the useArgs flag. Setting this flag to true will cause this task to append all of the command line arguments used to start the (String[]) method to the arguments passed to the child JVM.

Parameters: useArgs the useArgs flag

setUsesystemin

public void setUsesystemin(boolean useSystemIn)
Set the useSystemIn flag. Setting this flag to false will cause this task to not read System.in. This will cause the child JVM to never receive any bytes when it reads System.in. Setting this flag to false is useful in some Unix environments where processes cannot be put in the background when they read System.in.

Parameters: useSystemIn the useSystemIn flag

setWaitforchild

public void setWaitforchild(boolean waitForChild)
Set the waitForChild flag. Setting this flag to true will cause this task to wait for the child JVM to finish executing before the task completes. Setting this flag to false will cause this task to complete immediately after it starts the execution of the child JVM. Setting it false emulates the "&" background operator in most Unix shells and is most of set to false when launching server or GUI applications.

Parameters: waitForChild the waitForChild flag

Copyright (c) 2001-2002 - Apache Software Foundation