Class XObject

java.lang.Object
org.apache.xpath.Expression
org.apache.xpath.objects.XObject
All Implemented Interfaces:
Serializable, Cloneable, SourceLocator, ExpressionNode, XPathVisitable
Direct Known Subclasses:
NodeSequence, XBoolean, XNumber, XRTreeFrag, XString, XUnresolvedVariable, XUnresolvedVariableSimple

public class XObject extends Expression implements Serializable, Cloneable
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.
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  • Field Details

    • CLASS_NULL

      public static final int CLASS_NULL
      Constant for NULL object type
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    • CLASS_UNKNOWN

      public static final int CLASS_UNKNOWN
      Constant for UNKNOWN object type
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    • CLASS_BOOLEAN

      public static final int CLASS_BOOLEAN
      Constant for BOOLEAN object type
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    • CLASS_NUMBER

      public static final int CLASS_NUMBER
      Constant for NUMBER object type
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    • CLASS_STRING

      public static final int CLASS_STRING
      Constant for STRING object type
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    • CLASS_NODESET

      public static final int CLASS_NODESET
      Constant for NODESET object type
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    • CLASS_RTREEFRAG

      public static final int CLASS_RTREEFRAG
      Constant for RESULT TREE FRAGMENT object type
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    • CLASS_UNRESOLVEDVARIABLE

      public static final int CLASS_UNRESOLVEDVARIABLE
      Represents an unresolved variable type as an integer.
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  • Constructor Details

    • XObject

      public XObject()
      Create an XObject.
    • XObject

      public XObject(Object obj)
      Create an XObject.
      Parameters:
      obj - Can be any object, should be a specific type for derived classes, or null.
  • Method Details

    • execute

      public XObject execute(XPathContext xctxt) throws TransformerException
      For support of literal objects in xpaths.
      Specified by:
      execute in class Expression
      Parameters:
      xctxt - The XPath execution context.
      Returns:
      This object.
      Throws:
      TransformerException
    • allowDetachToRelease

      public void allowDetachToRelease(boolean allowRelease)
      Specify if it's OK for detach to release the iterator for reuse. This function should be called with a value of false for objects that are stored in variables. Calling this with a value of false on a XNodeSet will cause the nodeset to be cached.
      Parameters:
      allowRelease - true if it is OK for detach to release this iterator for pooling.
    • detach

      public void detach()
      Detaches the DTMIterator from the set which it iterated over, releasing any computational resources and placing the iterator in the INVALID state. After detach has been invoked, calls to nextNode or previousNode will raise a runtime exception.
    • destruct

      public void destruct()
      Forces the object to release it's resources. This is more harsh than detach().
    • reset

      public void reset()
      Reset for fresh reuse.
    • dispatchCharactersEvents

      public void dispatchCharactersEvents(ContentHandler ch) throws SAXException
      Directly call the characters method on the passed ContentHandler for the string-value. Multiple calls to the ContentHandler's characters methods may well occur for a single call to this method.
      Parameters:
      ch - A non-null reference to a ContentHandler.
      Throws:
      SAXException
    • create

      public static XObject create(Object val)
      Create the right XObject based on the type of the object passed. This function can not make an XObject that exposes DOM Nodes, NodeLists, and NodeIterators to the XSLT stylesheet as node-sets.
      Parameters:
      val - The java object which this object will wrap.
      Returns:
      the right XObject based on the type of the object passed.
    • create

      public static XObject create(Object val, XPathContext xctxt)
      Create the right XObject based on the type of the object passed. This function can make an XObject that exposes DOM Nodes, NodeLists, and NodeIterators to the XSLT stylesheet as node-sets.
      Parameters:
      val - The java object which this object will wrap.
      xctxt - The XPath context.
      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 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
    • numWithSideEffects

      public double numWithSideEffects() throws TransformerException
      Cast result object to a number, but allow side effects, such as the incrementing of an iterator.
      Returns:
      numeric value of the string conversion from the next node in the NodeSetDTM, or NAN if no node was found
      Throws:
      TransformerException
    • bool

      public boolean bool() throws TransformerException
      Cast result object to a boolean. Always issues an error.
      Returns:
      false
      Throws:
      TransformerException
    • boolWithSideEffects

      public boolean boolWithSideEffects() throws TransformerException
      Cast result object to a boolean, but allow side effects, such as the incrementing of an iterator.
      Returns:
      True if there is a next node in the nodeset
      Throws:
      TransformerException
    • xstr

      public XMLString xstr()
      Cast result object to a string.
      Returns:
      The string this wraps or the empty string if null
    • str

      public String str()
      Cast result object to a string.
      Returns:
      The object as a string
    • toString

      public String toString()
      Return the string representation of the object
      Overrides:
      toString in class Object
      Returns:
      the string representation of the object
    • rtf

      public int rtf(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(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
    • rtf

      public int rtf()
      For functions to override.
      Returns:
      null
    • object

      public 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
    • iter

      public DTMIterator iter() throws TransformerException
      Cast result object to a nodelist. Always issues an error.
      Returns:
      null
      Throws:
      TransformerException
    • getFresh

      public XObject getFresh()
      Get a fresh copy of the object. For use with variables.
      Returns:
      This object, unless overridden by subclass.
    • nodeset

      public org.w3c.dom.traversal.NodeIterator nodeset() throws TransformerException
      Cast result object to a nodelist. Always issues an error.
      Returns:
      null
      Throws:
      TransformerException
    • nodelist

      public NodeList nodelist() throws TransformerException
      Cast result object to a nodelist. Always issues an error.
      Returns:
      null
      Throws:
      TransformerException
    • mutableNodeset

      public NodeSetDTM mutableNodeset() throws TransformerException
      Cast result object to a nodelist. Always issues an error.
      Returns:
      The object as a NodeSetDTM.
      Throws:
      TransformerException
    • castToType

      public 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)
      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
    • fixupVariables

      public void fixupVariables(Vector vars, int globalsSize)
      XObjects should not normally need to fix up variables.
      Specified by:
      fixupVariables in class Expression
      Parameters:
      vars - List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame). NEEDSDOC @param globalsSize
    • appendToFsb

      public void appendToFsb(FastStringBuffer fsb)
      Cast result object to a string. NEEDSDOC @param fsb
    • callVisitors

      public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
      Description copied from interface: XPathVisitable
      This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.
      Specified by:
      callVisitors in interface XPathVisitable
      Parameters:
      owner - The owner of the visitor, where that path may be rewritten if needed.
      visitor - The visitor whose appropriate method will be called.
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    • deepEquals

      public boolean deepEquals(Expression expr)
      Description copied from class: Expression
      Compare this object with another object and see if they are equal, include the sub heararchy.
      Specified by:
      deepEquals in class Expression
      Parameters:
      expr - Another expression object.
      Returns:
      true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
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