org.apache.tools.ant.types
Class DataType

java.lang.Object
  extended by org.apache.tools.ant.ProjectComponent
      extended by org.apache.tools.ant.types.DataType
All Implemented Interfaces:
java.lang.Cloneable
Direct Known Subclasses:
AbstractFileSet, AbstractResourceCollectionWrapper, AbstractSelectorContainer, AntFilterReader, Archives, Assertions, BaseResourceCollectionContainer, BaseSelector, Compare, Description, ExtensionAdapter, ExtensionSet, FileList, FilterChain, FilterSet, ImageOperation, IsSigned, MappedResourceCollection, Mapper, Path, PatternSet, PropertySet, RedirectorElement, RegularExpression, Resource, ResourceComparator, ResourceList, Resources, ResourceSelectorContainer, SignedSelector, Substitution, XMLCatalog

public abstract class DataType
extends ProjectComponent
implements java.lang.Cloneable

Base class for those classes that can appear inside the build file as stand alone data types.

This class handles the common description attribute and provides a default implementation for reference handling and checking for circular references that is appropriate for types that can not be nested inside elements of the same type (i.e. <patternset> but not <path>).


Field Summary
protected  boolean checked
          Deprecated. since 1.7. The user should not be directly referencing variable. Please use setChecked(boolean) or isChecked() instead.
protected  Reference ref
          Deprecated. since 1.7. The user should not be directly referencing variable. Please use getRefid() instead.
 
Fields inherited from class org.apache.tools.ant.ProjectComponent
description, location, project
 
Constructor Summary
DataType()
           
 
Method Summary
protected  void checkAttributesAllowed()
          check that it is ok to set attributes, i.e that no reference is defined
protected  void checkChildrenAllowed()
          check that it is ok to add children, i.e that no reference is defined
protected  BuildException circularReference()
          Creates an exception that indicates the user has generated a loop of data types referencing each other.
 java.lang.Object clone()
           
protected  void dieOnCircularReference()
          Convenience method.
protected  void dieOnCircularReference(Project p)
          Convenience method.
protected  void dieOnCircularReference(java.util.Stack<java.lang.Object> stack, Project project)
          Check to see whether any DataType we hold references to is included in the Stack (which holds all DataType instances that directly or indirectly reference this instance, including this instance itself).
protected  java.lang.Object getCheckedRef()
          Performs the check for circular references and returns the referenced object.
protected
<T> T
getCheckedRef(java.lang.Class<T> requiredClass, java.lang.String dataTypeName)
          Performs the check for circular references and returns the referenced object.
protected
<T> T
getCheckedRef(java.lang.Class<T> requiredClass, java.lang.String dataTypeName, Project project)
          Performs the check for circular references and returns the referenced object.
protected  java.lang.Object getCheckedRef(Project p)
          Performs the check for circular references and returns the referenced object.
protected  java.lang.String getDataTypeName()
          Gets as descriptive as possible a name used for this datatype instance.
 Reference getRefid()
          get the reference set on this object
static void invokeCircularReferenceCheck(DataType dt, java.util.Stack<java.lang.Object> stk, Project p)
          Allow DataTypes outside org.apache.tools.ant.types to indirectly call dieOnCircularReference on nested DataTypes.
protected  boolean isChecked()
          The flag that is used to indicate that circular references have been checked.
 boolean isReference()
          Has the refid attribute of this element been set?
protected  BuildException noChildrenAllowed()
          Creates an exception that indicates that this XML element must not have child elements if the refid attribute is set.
static void pushAndInvokeCircularReferenceCheck(DataType dt, java.util.Stack<java.lang.Object> stk, Project p)
          Allow DataTypes outside org.apache.tools.ant.types to indirectly call dieOnCircularReference on nested DataTypes.
protected  void setChecked(boolean checked)
          Set the flag that is used to indicate that circular references have been checked.
 void setRefid(Reference ref)
          Set the value of the refid attribute.
protected  BuildException tooManyAttributes()
          Creates an exception that indicates that refid has to be the only attribute if it is set.
 java.lang.String toString()
          Basic DataType toString().
 
Methods inherited from class org.apache.tools.ant.ProjectComponent
getDescription, getLocation, getProject, log, log, setDescription, setLocation, setProject
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

ref

protected Reference ref
Deprecated. since 1.7. The user should not be directly referencing variable. Please use getRefid() instead.
Value to the refid attribute.


checked

protected boolean checked
Deprecated. since 1.7. The user should not be directly referencing variable. Please use setChecked(boolean) or isChecked() instead.
Are we sure we don't hold circular references?

Subclasses are responsible for setting this value to false if we'd need to investigate this condition (usually because a child element has been added that is a subclass of DataType).

Constructor Detail

DataType

public DataType()
Method Detail

isReference

public boolean isReference()
Has the refid attribute of this element been set?

Returns:
true if the refid attribute has been set

setRefid

public void setRefid(Reference ref)
Set the value of the refid attribute.

Subclasses may need to check whether any other attributes have been set as well or child elements have been created and thus override this method. if they do the must call super.setRefid.

Parameters:
ref - the reference to use

getDataTypeName

protected java.lang.String getDataTypeName()
Gets as descriptive as possible a name used for this datatype instance.

Returns:
String name.

dieOnCircularReference

protected void dieOnCircularReference()
Convenience method.

Since:
Ant 1.7

dieOnCircularReference

protected void dieOnCircularReference(Project p)
Convenience method.

Parameters:
p - the Ant Project instance against which to resolve references.
Since:
Ant 1.7

dieOnCircularReference

protected void dieOnCircularReference(java.util.Stack<java.lang.Object> stack,
                                      Project project)
                               throws BuildException
Check to see whether any DataType we hold references to is included in the Stack (which holds all DataType instances that directly or indirectly reference this instance, including this instance itself).

If one is included, throw a BuildException created by circularReference.

This implementation is appropriate only for a DataType that cannot hold other DataTypes as children.

The general contract of this method is that it shouldn't do anything if checked is true and set it to true on exit.

Parameters:
stack - the stack of references to check.
project - the project to use to dereference the references.
Throws:
BuildException - on error.

invokeCircularReferenceCheck

public static void invokeCircularReferenceCheck(DataType dt,
                                                java.util.Stack<java.lang.Object> stk,
                                                Project p)
Allow DataTypes outside org.apache.tools.ant.types to indirectly call dieOnCircularReference on nested DataTypes.

Parameters:
dt - the DataType to check.
stk - the stack of references to check.
p - the project to use to dereference the references.
Throws:
BuildException - on error.
Since:
Ant 1.7

pushAndInvokeCircularReferenceCheck

public static void pushAndInvokeCircularReferenceCheck(DataType dt,
                                                       java.util.Stack<java.lang.Object> stk,
                                                       Project p)
Allow DataTypes outside org.apache.tools.ant.types to indirectly call dieOnCircularReference on nested DataTypes.

Pushes dt on the stack, runs dieOnCircularReference and pops it again.

Parameters:
dt - the DataType to check.
stk - the stack of references to check.
p - the project to use to dereference the references.
Throws:
BuildException - on error.
Since:
Ant 1.8.0

getCheckedRef

protected java.lang.Object getCheckedRef()
Performs the check for circular references and returns the referenced object.

Returns:
the dereferenced object.
Throws:
BuildException - if the reference is invalid (circular ref, wrong class, etc).
Since:
Ant 1.7

getCheckedRef

protected java.lang.Object getCheckedRef(Project p)
Performs the check for circular references and returns the referenced object.

Parameters:
p - the Ant Project instance against which to resolve references.
Returns:
the dereferenced object.
Throws:
BuildException - if the reference is invalid (circular ref, wrong class, etc).
Since:
Ant 1.7

getCheckedRef

protected <T> T getCheckedRef(java.lang.Class<T> requiredClass,
                              java.lang.String dataTypeName)
Performs the check for circular references and returns the referenced object.

Parameters:
requiredClass - the class that this reference should be a subclass of.
dataTypeName - the name of the datatype that the reference should be (error message use only).
Returns:
the dereferenced object.
Throws:
BuildException - if the reference is invalid (circular ref, wrong class, etc).

getCheckedRef

protected <T> T getCheckedRef(java.lang.Class<T> requiredClass,
                              java.lang.String dataTypeName,
                              Project project)
Performs the check for circular references and returns the referenced object. This version allows the fallback Project instance to be specified.

Parameters:
requiredClass - the class that this reference should be a subclass of.
dataTypeName - the name of the datatype that the reference should be (error message use only).
project - the fallback Project instance for dereferencing.
Returns:
the dereferenced object.
Throws:
BuildException - if the reference is invalid (circular ref, wrong class, etc), or if project is null.
Since:
Ant 1.7

tooManyAttributes

protected BuildException tooManyAttributes()
Creates an exception that indicates that refid has to be the only attribute if it is set.

Returns:
the exception to throw

noChildrenAllowed

protected BuildException noChildrenAllowed()
Creates an exception that indicates that this XML element must not have child elements if the refid attribute is set.

Returns:
the exception to throw

circularReference

protected BuildException circularReference()
Creates an exception that indicates the user has generated a loop of data types referencing each other.

Returns:
the exception to throw

isChecked

protected boolean isChecked()
The flag that is used to indicate that circular references have been checked.

Returns:
true if circular references have been checked

setChecked

protected void setChecked(boolean checked)
Set the flag that is used to indicate that circular references have been checked.

Parameters:
checked - if true, if circular references have been checked

getRefid

public Reference getRefid()
get the reference set on this object

Returns:
the reference or null

checkAttributesAllowed

protected void checkAttributesAllowed()
check that it is ok to set attributes, i.e that no reference is defined

Throws:
BuildException - if not allowed
Since:
Ant 1.6

checkChildrenAllowed

protected void checkChildrenAllowed()
check that it is ok to add children, i.e that no reference is defined

Throws:
BuildException - if not allowed
Since:
Ant 1.6

toString

public java.lang.String toString()
Basic DataType toString().

Overrides:
toString in class java.lang.Object
Returns:
this DataType formatted as a String.

clone

public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException
Overrides:
clone in class ProjectComponent
Returns:
a shallow copy of this DataType.
Throws:
java.lang.CloneNotSupportedException - if there is a problem.
Since:
Ant 1.7