org.apache.xpath.objects
Class XObject

java.lang.Object
  |
  +--org.apache.xpath.Expression
        |
        +--org.apache.xpath.objects.XObject

Direct Known Subclasses:

XBoolean, XNodeSet, XNull, XNumber, XRTreeFrag, XString, XUnresolvedVariable

public class XObject

extends Expression

implements java.io.Serializable

This class represents an XPath object, and is capable of converting the object to various types, such as a string. This class acts as the base class to other XPath type objects, such as XString, and provides polymorphic casting capabilities.

See Also:

Serialized Form

Field Summary

static int	CLASS_BOOLEAN Constant for BOOLEAN object type
static int	CLASS_NODESET Constant for NODESET object type
static int	CLASS_NULL Constant for NULL object type
static int	CLASS_NUMBER Constant for NUMBER object type
static int	CLASS_RTREEFRAG Constant for RESULT TREE FRAGMENT object type
static int	CLASS_STRING Constant for STRING object type
static int	CLASS_UNKNOWN Constant for UNKNOWN object type
static int	CLASS_UNRESOLVEDVARIABLE Represents an unresolved variable type as an integer.

Constructor Summary

XObject()
Create an XObject.

XObject(java.lang.Object obj)
Create an XObject.

Method Summary

boolean	bool() Cast result object to a boolean.
java.lang.Object	castToType(int t, XPathContext support) Cast object to type t.
static XObject	create(java.lang.Object val) Create the right XObject based on the type of the object passed.
boolean	equals(XObject obj2) Tell if two objects are functionally equal.
XObject	execute(XPathContext xctxt) For support of literal objects in xpaths.
int	getType() Tell what kind of class this is.
java.lang.String	getTypeString() Given a request type, return the equivalent string.
boolean	greaterThan(XObject obj2) Tell if one object is greater than the other.
boolean	greaterThanOrEqual(XObject obj2) Tell if one object is greater than or equal to the other.
boolean	lessThan(XObject obj2) Tell if one object is less than the other.
boolean	lessThanOrEqual(XObject obj2) Tell if one object is less than or equal to the other.
NodeSet	mutableNodeset() Cast result object to a nodelist.
NodeIterator	nodeset() Cast result object to a nodelist.
boolean	notEquals(XObject obj2) Tell if two objects are functionally not equal.
double	num() Cast result object to a number.
java.lang.Object	object() Return a java object that's closest to the representation that should be handed to an extension.
DocumentFragment	rtree() For functions to override.
DocumentFragment	rtree(XPathContext support) Cast result object to a result tree fragment.
java.lang.String	str() Cast result object to a string.
java.lang.String	toString() Return the string representation of the object

Methods inherited from class org.apache.xpath.Expression

assert, canTraverseOutsideSubtree, error, setSourceLocator, warn

Methods inherited from class java.lang.Object

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

Field Detail

CLASS_NULL

public static final int CLASS_NULL

Constant for NULL object type

CLASS_UNKNOWN

public static final int CLASS_UNKNOWN

Constant for UNKNOWN object type

CLASS_BOOLEAN

public static final int CLASS_BOOLEAN

Constant for BOOLEAN object type

CLASS_NUMBER

public static final int CLASS_NUMBER

Constant for NUMBER object type

CLASS_STRING

public static final int CLASS_STRING

Constant for STRING object type

CLASS_NODESET

public static final int CLASS_NODESET

Constant for NODESET object type

CLASS_RTREEFRAG

public static final int CLASS_RTREEFRAG

Constant for RESULT TREE FRAGMENT object type

CLASS_UNRESOLVEDVARIABLE

public static final int CLASS_UNRESOLVEDVARIABLE

Represents an unresolved variable type as an integer.

Constructor Detail

XObject

public XObject()

Create an XObject.

XObject

public XObject(java.lang.Object obj)

Create an XObject.

Parameters:

obj - Can be any object, should be a specific type for derived classes, or null.

Method Detail

execute

public XObject execute(XPathContext xctxt)
                throws TransformerException

For support of literal objects in xpaths.

Parameters:

xctxt - The XPath execution context.

Returns:

This object.

Throws:

TransformerException -

Overrides:

execute in class Expression

create

public static XObject create(java.lang.Object val)

Create the right XObject based on the type of the object passed.

Parameters:

val - The java object which this object will wrap.

Returns:

the right XObject based on the type of the object passed.

getType

public int getType()

Tell what kind of class this is.

Returns:

CLASS_UNKNOWN

getTypeString

public java.lang.String getTypeString()

Given a request type, return the equivalent string. For diagnostic purposes.

Returns:

type string "#UNKNOWN" + object class name

num

public double num()
           throws TransformerException

Cast result object to a number. Always issues an error.

Returns:

0.0

Throws:

TransformerException -

bool

public boolean bool()
             throws TransformerException

Cast result object to a boolean. Always issues an error.

Returns:

false

Throws:

TransformerException -

str

public java.lang.String str()

Cast result object to a string.

Returns:

The object as a string

toString

public java.lang.String toString()

Return the string representation of the object

Returns:

the string representation of the object

Overrides:

toString in class java.lang.Object

rtree

public DocumentFragment rtree(XPathContext support)

Cast result object to a result tree fragment.

Parameters:

support - XPath context to use for the conversion

Returns:

the objec as a result tree fragment.

rtree

public DocumentFragment rtree()

For functions to override.

Returns:

null

object

public java.lang.Object object()

Return a java object that's closest to the representation that should be handed to an extension.

Returns:

The object that this class wraps

nodeset

public NodeIterator nodeset()
                     throws TransformerException

Cast result object to a nodelist. Always issues an error.

Returns:

null

Throws:

TransformerException -

mutableNodeset

public NodeSet mutableNodeset()
                       throws TransformerException

Cast result object to a nodelist. Always issues an error.

Returns:

The object as a NodeSet.

Throws:

TransformerException -

castToType

public java.lang.Object castToType(int t,
                                   XPathContext support)
                            throws TransformerException

Cast object to type t.

Parameters:

t - Type of object to cast this to

support - XPath context to use for the conversion

Returns:

This object as the given type t

Throws:

TransformerException -

lessThan

public boolean lessThan(XObject obj2)
                 throws TransformerException

Tell if one object is less than the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is less than the given object

Throws:

TransformerException -

lessThanOrEqual

public boolean lessThanOrEqual(XObject obj2)
                        throws TransformerException

Tell if one object is less than or equal to the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is less than or equal to the given object

Throws:

TransformerException -

greaterThan

public boolean greaterThan(XObject obj2)
                    throws TransformerException

Tell if one object is greater than the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is greater than the given object

Throws:

TransformerException -

greaterThanOrEqual

public boolean greaterThanOrEqual(XObject obj2)
                           throws TransformerException

Tell if one object is greater than or equal to the other.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is greater than or equal to the given object

Throws:

TransformerException -

equals

public boolean equals(XObject obj2)
               throws TransformerException

Tell if two objects are functionally equal.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is equal to the given object

Throws:

TransformerException -

notEquals

public boolean notEquals(XObject obj2)
                  throws TransformerException

Tell if two objects are functionally not equal.

Parameters:

obj2 - Object to compare this to

Returns:

True if this object is not equal to the given object

Throws:

TransformerException -