Package org.apache.tools.ant.taskdefs

Class Property

java.lang.Object

org.apache.tools.ant.ProjectComponent

org.apache.tools.ant.Task

org.apache.tools.ant.taskdefs.Property

All Implemented Interfaces:

Cloneable

public class Property
extends Task

Sets a property by name, or set of properties (from file or resource) in the project.

Properties are immutable: whoever sets a property first freezes it for the rest of the build; they are most definitely not variable.

There are seven ways to set properties:

• By supplying both the name and value attribute.
• By supplying the name and nested text.
• By supplying both the name and refid attribute.
• By setting the file attribute with the filename of the property file to load. This property file has the format as defined by the file used in the class java.util.Properties.
• By setting the url attribute with the url from which to load the properties. This url must be directed to a file that has the format as defined by the file used in the class java.util.Properties.
• By setting the resource attribute with the resource name of the property file to load. This property file has the format as defined by the file used in the class java.util.Properties.
• By setting the environment attribute with a prefix to use. Properties will be defined for every environment variable by prefixing the supplied name and a period to the name of the variable.
• By setting the runtime attribute with a prefix to use. Properties prefix.availableProcessors, prefix.freeMemory, prefix.totalMemory and prefix.maxMemory will be defined with values that correspond to the corresponding methods of the Runtime class.

Although combinations of these ways are possible, only one should be used at a time. Problems might occur with the order in which properties are set, for instance.

The value part of the properties being set, might contain references to other properties. These references are resolved at the time these properties are set. This also holds for properties loaded from a property file.

Properties are case sensitive.

Since:

Ant 1.1

Field Summary

Fields

Modifier and Type	Field	Description
protected Path	classpath
protected String	env
protected File	file
protected String	name
protected String	prefix
protected Reference	ref
protected String	resource
protected URL	url
protected boolean	userProperty
protected String	value

Fields inherited from class org.apache.tools.ant.Task

target, taskName, taskType, wrapper

Fields inherited from class org.apache.tools.ant.ProjectComponent

description, location, project

Constructor Summary

Constructors

Modifier	Constructor	Description
	Property()	Constructor for Property.
protected	Property(boolean userProperty)	Constructor for Property.
protected	Property(boolean userProperty, Project fallback)	Constructor for Property.

Method Summary

Modifier and Type	Method	Description
protected void	addProperties(Properties props)	iterate through a set of properties, resolve them then assign them
protected void	addProperty(String n, Object v)	add a name value pair to the project property set
protected void	addProperty(String n, String v)	add a name value pair to the project property set
void	addText(String msg)	Set a (multiline) property as nested text.
Path	createClasspath()	The classpath to use when looking up a resource.
void	execute()	set the property in the project to the value.
Path	getClasspath()	Get the classpath used when looking up a resource.
String	getEnvironment()	Get the environment attribute.
File	getFile()	Get the file attribute.
String	getName()	Get the property name.
String	getPrefix()	Get the prefix attribute.
boolean	getPrefixValues()	Whether to apply the prefix when expanding properties on the right hand side of a properties file as well.
Reference	getRefid()	Get the refid attribute.
String	getResource()	Get the resource attribute.
String	getRuntime()	Get the runtime attribute.
URL	getUrl()	Get the url attribute.
String	getValue()	Get the property value.
protected void	loadEnvironment(String prefix)	load the environment values
protected void	loadFile(File file)	load properties from a file
protected void	loadResource(String name)	load properties from a resource in the current classpath
protected void	loadRuntime(String prefix)	load the runtime values
protected void	loadUrl(URL url)	load properties from a url
void	setBasedir(File basedir)	Sets 'basedir' attribute.
void	setClasspath(Path classpath)	The classpath to use when looking up a resource.
void	setClasspathRef(Reference r)	the classpath to use when looking up a resource, given as reference to a <path> defined elsewhere
void	setEnvironment(String env)	Prefix to use when retrieving environment variables.
void	setFile(File file)	Filename of a property file to load.
void	setLocation(File location)	Sets the property to the absolute filename of the given file.
void	setName(String name)	The name of the property to set.
void	setPrefix(String prefix)	Prefix to apply to properties loaded using file or resource.
void	setPrefixValues(boolean b)	Whether to apply the prefix when expanding properties on the right hand side of a properties file as well.
void	setRefid(Reference ref)	Sets a reference to an Ant datatype declared elsewhere.
void	setRelative(boolean relative)	Sets 'relative' attribute.
void	setResource(String resource)	The resource name of a property file to load
void	setRuntime(String prefix)	Prefix to use when retrieving Runtime properties.
void	setUrl(URL url)	The url from which to load properties.
void	setUserProperty(boolean userProperty)	Deprecated. since 1.5.x.
void	setValue(Object value)	Set the value of the property.
void	setValue(String value)	Set the value of the property as a String.
String	toString()	get the value of this property

Methods inherited from class org.apache.tools.ant.Task

bindToOwner, getOwningTarget, getRuntimeConfigurableWrapper, getTaskName, getTaskType, getWrapper, handleErrorFlush, handleErrorOutput, handleFlush, handleInput, handleOutput, init, isInvalid, log, log, log, log, maybeConfigure, perform, reconfigure, setOwningTarget, setRuntimeConfigurableWrapper, setTaskName, setTaskType

Methods inherited from class org.apache.tools.ant.ProjectComponent

clone, getDescription, getLocation, getProject, setDescription, setLocation, setProject

Methods inherited from class java.lang.Object

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

Field Details

name

protected String name

value

protected String value

file

protected File file

url

protected URL url

resource

protected String resource

classpath

protected Path classpath

env

protected String env

ref

protected Reference ref

prefix

protected String prefix

userProperty

protected boolean userProperty

Constructor Details

Property

public Property()

Constructor for Property.

Property

protected Property(boolean userProperty)

Constructor for Property.

Parameters:

userProperty - if true this is a user property

Since:

Ant 1.5

Property

protected Property(boolean userProperty,
 Project fallback)

Constructor for Property.

Parameters:

userProperty - if true this is a user property

fallback - a project to use to look for references if the reference is not in the current project

Since:

Ant 1.5

Method Details

setRelative

public void setRelative(boolean relative)

Sets 'relative' attribute.

Parameters:

relative - new value

Since:

Ant 1.8.0

setBasedir

public void setBasedir(File basedir)

Sets 'basedir' attribute.

Parameters:

basedir - new value

Since:

Ant 1.8.0

setName

public void setName(String name)

The name of the property to set.

Parameters:

name - property name

getName

public String getName()

Get the property name.

Returns:

the property name

setLocation

public void setLocation(File location)

Sets the property to the absolute filename of the given file. If the value of this attribute is an absolute path, it is left unchanged (with / and \ characters converted to the current platforms conventions). Otherwise it is taken as a path relative to the project's basedir and expanded.

Parameters:

location - path to set

setValue

public void setValue(Object value)

Set the value of the property.

Parameters:

value - the value to use.

setValue

public void setValue(String value)

Set the value of the property as a String.

Parameters:

value - value to assign

addText

public void addText(String msg)

Set a (multiline) property as nested text.

Parameters:

msg - the text to append to the output text

Since:

Ant 1.8.0

getValue

public String getValue()

Get the property value.

Returns:

the property value

setFile

public void setFile(File file)

Filename of a property file to load.

Parameters:

file - filename

getFile

public File getFile()

Get the file attribute.

Returns:

the file attribute

setUrl

public void setUrl(URL url)

The url from which to load properties.

Parameters:

url - url string

getUrl

public URL getUrl()

Get the url attribute.

Returns:

the url attribute

setPrefix

public void setPrefix(String prefix)

Prefix to apply to properties loaded using file or resource. A "." is appended to the prefix if not specified.

Parameters:

prefix - prefix string

Since:

Ant 1.5

getPrefix

public String getPrefix()

Get the prefix attribute.

Returns:

the prefix attribute

Since:

Ant 1.5

setPrefixValues

public void setPrefixValues(boolean b)

Whether to apply the prefix when expanding properties on the right hand side of a properties file as well.

Parameters:

b - boolean

Since:

Ant 1.8.2

getPrefixValues

public boolean getPrefixValues()

Whether to apply the prefix when expanding properties on the right hand side of a properties file as well.

Returns:

boolean

Since:

Ant 1.8.2

setRefid

public void setRefid(Reference ref)

Sets a reference to an Ant datatype declared elsewhere. Only yields reasonable results for references PATH like structures or properties.

Parameters:

ref - reference

getRefid

public Reference getRefid()

Get the refid attribute.

Returns:

the refid attribute

setResource

public void setResource(String resource)

The resource name of a property file to load

Parameters:

resource - resource on classpath

getResource

public String getResource()

Get the resource attribute.

Returns:

the resource attribute

setEnvironment

public void setEnvironment(String env)

Prefix to use when retrieving environment variables. Thus if you specify environment="myenv" you will be able to access OS-specific environment variables via property names "myenv.PATH" or "myenv.TERM".

Note that if you supply a property name with a final "." it will not be doubled. ie environment="myenv." will still allow access of environment variables through "myenv.PATH" and "myenv.TERM". This functionality is currently only implemented on select platforms. Feel free to send patches to increase the number of platforms this functionality is supported on ;).

Note also that properties are case sensitive, even if the environment variables on your operating system are not, e.g. it will be ${env.Path} not ${env.PATH} on Windows 2000.

Parameters:

env - prefix

getEnvironment

public String getEnvironment()

Get the environment attribute.

Returns:

the environment attribute

Since:

Ant 1.5

setRuntime

public void setRuntime(String prefix)

Prefix to use when retrieving Runtime properties.

Properties prefix.availableProcessors, prefix.freeMemory, prefix.totalMemory and prefix.maxMemory will be defined with values that correspond to the corresponding methods of the Runtime class.

Note that if you supply a prefix name with a final "." it will not be doubled. ie runtime="myrt." will still allow access of property through "myrt.availableProcessors" and "myrt.freeMemory".

The property values are snapshots taken at the point in time when the property has been executed.

Parameters:

prefix - prefix

Since:

Ant 1.10.4

getRuntime

public String getRuntime()

Get the runtime attribute.

Returns:

the runtime attribute

Since:

Ant 1.10.4

setClasspath

public void setClasspath(Path classpath)

The classpath to use when looking up a resource.

Parameters:

classpath - to add to any existing classpath

createClasspath

public Path createClasspath()

The classpath to use when looking up a resource.

Returns:

a path to be configured

setClasspathRef

public void setClasspathRef(Reference r)

the classpath to use when looking up a resource, given as reference to a <path> defined elsewhere

Parameters:

r - a reference to a classpath

getClasspath

public Path getClasspath()

Get the classpath used when looking up a resource.

Returns:

the classpath

Since:

Ant 1.5

setUserProperty

@Deprecated
public void setUserProperty(boolean userProperty)

Deprecated.

since 1.5.x. This was never a supported feature and has been deprecated without replacement.

Parameters:

userProperty - ignored

toString

public String toString()

get the value of this property

Overrides:

toString in class Object

Returns:

the current value or the empty string

execute

public void execute()
             throws BuildException

set the property in the project to the value. if the task was give a file, resource, env or runtime attribute here is where it is loaded

Overrides:

execute in class Task

Throws:

BuildException - on error

loadUrl

protected void loadUrl(URL url)
                throws BuildException

load properties from a url

Parameters:

url - url to load from

Throws:

BuildException - on error

loadFile

protected void loadFile(File file)
                 throws BuildException

load properties from a file

Parameters:

file - file to load

Throws:

BuildException - on error

loadResource

protected void loadResource(String name)

load properties from a resource in the current classpath

Parameters:

name - name of resource to load

loadEnvironment

protected void loadEnvironment(String prefix)

load the environment values

Parameters:

prefix - prefix to place before them

loadRuntime

protected void loadRuntime(String prefix)

load the runtime values

Parameters:

prefix - prefix to place before them

Since:

1.10.4

addProperties

protected void addProperties(Properties props)

iterate through a set of properties, resolve them then assign them

Parameters:

props - the properties to iterate over

addProperty

protected void addProperty(String n,
 String v)

add a name value pair to the project property set

Parameters:

n - name of property

v - value to set

addProperty

protected void addProperty(String n,
 Object v)

add a name value pair to the project property set

Parameters:

n - name of property

v - value to set

Since:

Ant 1.8