org.apache.tools.ant
Class ProjectHelper

java.lang.Object
  |
  +--org.apache.tools.ant.ProjectHelper
Direct Known Subclasses:
ProjectHelper2, ProjectHelperImpl

public class ProjectHelper
extends java.lang.Object

Configures a Project (complete with Targets and Tasks) based on a XML build file. It'll rely on a plugin to do the actual processing of the xml file. This class also provide static wrappers for common introspection. All helper plugins must provide backward compatibility with the original ant patterns, unless a different behavior is explicitly specified. For example, if namespace is used on the <project> tag the helper can expect the entire build file to be namespace-enabled. Namespaces or helper-specific tags can provide meta-information to the helper, allowing it to use new ( or different policies ). However, if no namespace is used the behavior should be exactly identical with the default helper.


Field Summary
static java.lang.String ANT_CORE_URI
          The URI for ant name space
static java.lang.String ANT_CURRENT_URI
          The URI for antlib current definitions
static java.lang.String ANT_TYPE
          Polymorphic attribute
static java.lang.String ANTLIB_URI
          The URI for defined types/tasks - the format is antlib:
static java.lang.String HELPER_PROPERTY
          Name of JVM system property which provides the name of the ProjectHelper class to use.
static java.lang.String SERVICE_ID
          The service identifier in jars which provide Project Helper implementations.
 
Constructor Summary
ProjectHelper()
          Default constructor
 
Method Summary
static BuildException addLocationToBuildException(BuildException ex, Location newLocation)
          Add location to build exception.
static void addText(Project project, java.lang.Object target, char[] buf, int start, int count)
          Adds the content of #PCDATA sections to an element.
static void addText(Project project, java.lang.Object target, java.lang.String text)
          Adds the content of #PCDATA sections to an element.
static void configure(java.lang.Object target, org.xml.sax.AttributeList attrs, Project project)
          Deprecated. Use IntrospectionHelper for each property
static void configureProject(Project project, java.io.File buildFile)
          Deprecated. Use the non-static parse method
static java.lang.String extractNameFromComponentName(java.lang.String componentName)
          extract the element name from a component name
static java.lang.String extractUriFromComponentName(java.lang.String componentName)
          extract a uri from a component name
static java.lang.String genComponentName(java.lang.String uri, java.lang.String name)
          Map a namespaced {uri,name} to an internal string format.
static java.lang.ClassLoader getContextClassLoader()
          Deprecated. Use LoaderUtils.getContextClassLoader()
 java.util.Vector getImportStack()
          EXPERIMENTAL WILL_CHANGE Import stack.
static ProjectHelper getProjectHelper()
          Discovers a project helper instance.
 void parse(Project project, java.lang.Object source)
          Parses the project file, configuring the project as it goes.
static void parsePropertyString(java.lang.String value, java.util.Vector fragments, java.util.Vector propertyRefs)
          Deprecated. Use PropertyHelper
static java.lang.String replaceProperties(Project project, java.lang.String value)
          Deprecated. Use project.replaceProperties()
static java.lang.String replaceProperties(Project project, java.lang.String value, java.util.Hashtable keys)
          Deprecated. Use PropertyHelper
static void storeChild(Project project, java.lang.Object parent, java.lang.Object child, java.lang.String tag)
          Stores a configured child element within its parent object.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

ANT_CORE_URI

public static final java.lang.String ANT_CORE_URI
The URI for ant name space

See Also:
Constant Field Values

ANT_CURRENT_URI

public static final java.lang.String ANT_CURRENT_URI
The URI for antlib current definitions

See Also:
Constant Field Values

ANTLIB_URI

public static final java.lang.String ANTLIB_URI
The URI for defined types/tasks - the format is antlib:

See Also:
Constant Field Values

ANT_TYPE

public static final java.lang.String ANT_TYPE
Polymorphic attribute

See Also:
Constant Field Values

HELPER_PROPERTY

public static final java.lang.String HELPER_PROPERTY
Name of JVM system property which provides the name of the ProjectHelper class to use.

See Also:
Constant Field Values

SERVICE_ID

public static final java.lang.String SERVICE_ID
The service identifier in jars which provide Project Helper implementations.

See Also:
Constant Field Values
Constructor Detail

ProjectHelper

public ProjectHelper()
Default constructor

Method Detail

configureProject

public static void configureProject(Project project,
                                    java.io.File buildFile)
                             throws BuildException
Deprecated. Use the non-static parse method

Configures the project with the contents of the specified XML file.

Parameters:
project - The project to configure. Must not be null.
buildFile - An XML file giving the project's configuration. Must not be null.
Throws:
BuildException - if the configuration is invalid or cannot be read

getImportStack

public java.util.Vector getImportStack()
EXPERIMENTAL WILL_CHANGE Import stack. Used to keep track of imported files. Error reporting should display the import path.

Returns:
the stack of import source objects.

parse

public void parse(Project project,
                  java.lang.Object source)
           throws BuildException
Parses the project file, configuring the project as it goes.

Parameters:
project - The project for the resulting ProjectHelper to configure. Must not be null.
source - The source for XML configuration. A helper must support at least File, for backward compatibility. Helpers may support URL, InputStream, etc or specialized types.
Throws:
BuildException - if the configuration is invalid or cannot be read
Since:
Ant1.5

getProjectHelper

public static ProjectHelper getProjectHelper()
                                      throws BuildException
Discovers a project helper instance. Uses the same patterns as JAXP, commons-logging, etc: a system property, a JDK1.3 service discovery, default.

Returns:
a ProjectHelper, either a custom implementation if one is available and configured, or the default implementation otherwise.
Throws:
BuildException - if a specified helper class cannot be loaded/instantiated.

getContextClassLoader

public static java.lang.ClassLoader getContextClassLoader()
Deprecated. Use LoaderUtils.getContextClassLoader()

JDK1.1 compatible access to the context class loader. Cut&paste from JAXP.

Returns:
the current context class loader, or null if the context class loader is unavailable.

configure

public static void configure(java.lang.Object target,
                             org.xml.sax.AttributeList attrs,
                             Project project)
                      throws BuildException
Deprecated. Use IntrospectionHelper for each property

Configures an object using an introspection handler.

Parameters:
target - The target object to be configured. Must not be null.
attrs - A list of attributes to configure within the target. Must not be null.
project - The project containing the target. Must not be null.
Throws:
BuildException - if any of the attributes can't be handled by the target

addText

public static void addText(Project project,
                           java.lang.Object target,
                           char[] buf,
                           int start,
                           int count)
                    throws BuildException
Adds the content of #PCDATA sections to an element.

Parameters:
project - The project containing the target. Must not be null.
target - The target object to be configured. Must not be null.
buf - A character array of the text within the element. Will not be null.
start - The start element in the array.
count - The number of characters to read from the array.
Throws:
BuildException - if the target object doesn't accept text

addText

public static void addText(Project project,
                           java.lang.Object target,
                           java.lang.String text)
                    throws BuildException
Adds the content of #PCDATA sections to an element.

Parameters:
project - The project containing the target. Must not be null.
target - The target object to be configured. Must not be null.
text - Text to add to the target. May be null, in which case this method call is a no-op.
Throws:
BuildException - if the target object doesn't accept text

storeChild

public static void storeChild(Project project,
                              java.lang.Object parent,
                              java.lang.Object child,
                              java.lang.String tag)
Stores a configured child element within its parent object.

Parameters:
project - Project containing the objects. May be null.
parent - Parent object to add child to. Must not be null.
child - Child object to store in parent. Should not be null.
tag - Name of element which generated the child. May be null, in which case the child is not stored.

replaceProperties

public static java.lang.String replaceProperties(Project project,
                                                 java.lang.String value)
                                          throws BuildException
Deprecated. Use project.replaceProperties()

Replaces ${xxx} style constructions in the given value with the string value of the corresponding properties.

Parameters:
project - The project containing the properties to replace. Must not be null.
value - The string to be scanned for property references. May be null.
Returns:
the original string with the properties replaced, or null if the original string is null.
Throws:
BuildException - if the string contains an opening ${ without a closing }
Since:
1.5

replaceProperties

public static java.lang.String replaceProperties(Project project,
                                                 java.lang.String value,
                                                 java.util.Hashtable keys)
                                          throws BuildException
Deprecated. Use PropertyHelper

Replaces ${xxx} style constructions in the given value with the string value of the corresponding data types.

Parameters:
project - The container project. This is used solely for logging purposes. Must not be null.
value - The string to be scanned for property references. May be null, in which case this method returns immediately with no effect.
keys - Mapping (String to String) of property names to their values. Must not be null.
Returns:
the original string with the properties replaced, or null if the original string is null.
Throws:
BuildException - if the string contains an opening ${ without a closing }

parsePropertyString

public static void parsePropertyString(java.lang.String value,
                                       java.util.Vector fragments,
                                       java.util.Vector propertyRefs)
                                throws BuildException
Deprecated. Use PropertyHelper

Parses a string containing ${xxx} style property references into two lists. The first list is a collection of text fragments, while the other is a set of string property names. null entries in the first list indicate a property reference from the second list.

Parameters:
value - Text to parse. Must not be null.
fragments - List to add text fragments to. Must not be null.
propertyRefs - List to add property names to. Must not be null.
Throws:
BuildException - if the string contains an opening ${ without a closing }

genComponentName

public static java.lang.String genComponentName(java.lang.String uri,
                                                java.lang.String name)
Map a namespaced {uri,name} to an internal string format. For BC purposes the names from the ant core uri will be mapped to "name", other names will be mapped to uri + ":" + name.

Parameters:
uri - The namepace URI
name - The localname
Returns:
The stringified form of the ns name

extractUriFromComponentName

public static java.lang.String extractUriFromComponentName(java.lang.String componentName)
extract a uri from a component name

Parameters:
componentName - The stringified form for {uri, name}
Returns:
The uri or "" if not present

extractNameFromComponentName

public static java.lang.String extractNameFromComponentName(java.lang.String componentName)
extract the element name from a component name

Parameters:
componentName - The stringified form for {uri, name}
Returns:
The element name of the component

addLocationToBuildException

public static BuildException addLocationToBuildException(BuildException ex,
                                                         Location newLocation)
Add location to build exception.

Parameters:
ex - the build exception, if the build exception does not include
newLocation - the location of the calling task (may be null)
Returns:
a new build exception based in the build exception with location set to newLocation. If the original exception did not have a location, just return the build exception


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