org.exist.xquery
Class JavaCall
java.lang.Object
org.exist.xquery.AbstractExpression
org.exist.xquery.PathExpr
org.exist.xquery.Function
org.exist.xquery.JavaCall
- All Implemented Interfaces:
- CompiledExpression, CompiledXQuery, Expression
- public class JavaCall
- extends Function
A special function call to a Java method or constructor.
This class handles all function calls who's namespace URI
starts with "java:".
- Author:
- Wolfgang Meier (wolfgang@exist-db.org)
Methods inherited from class org.exist.xquery.Function |
createFunction, dump, getArgument, getArgumentCount, getArguments, getASTNode, getDependencies, getParent, getSignature, isCalledAs, setASTNode, setParent, setPrimaryAxis, toString |
Methods inherited from class org.exist.xquery.PathExpr |
accept, add, add, addPath, addPredicate, dump, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLiteralValue, getSource, isValid, replaceLastExpression, reset, resetState, setContext, setSource |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
JavaCall
public JavaCall(XQueryContext context,
QName qname)
throws XPathException
- Parameters:
context
- qname
- the of the function
getName
public QName getName()
- Description copied from class:
Function
- Return the name of this function.
- Overrides:
getName
in class Function
- Returns:
- name of this function
getCardinality
public int getCardinality()
- Description copied from class:
AbstractExpression
- The default cardinality is
Cardinality.EXACTLY_ONE
.
- Specified by:
getCardinality
in interface Expression
- Overrides:
getCardinality
in class Function
setArguments
public void setArguments(java.util.List arguments)
throws XPathException
- Description copied from class:
Function
- Set the (static) arguments for this function from a list of expressions.
This will also check the type and cardinality of the
passed argument expressions.
- Overrides:
setArguments
in class Function
- Parameters:
arguments
-
- Throws:
XPathException
analyze
public void analyze(AnalyzeContextInfo contextInfo)
throws XPathException
- Description copied from interface:
Expression
- Statically analyze the expression and its subexpressions.
During the static analysis phase, the query engine can detect
unknown variables and some type errors.
- Specified by:
analyze
in interface Expression
- Overrides:
analyze
in class Function
- Throws:
XPathException
eval
public Sequence eval(Sequence contextSequence,
Item contextItem)
throws XPathException
- Description copied from interface:
Expression
- Evaluate the expression represented by this object.
Depending on the context in which this expression is executed,
either the context sequence, the context item or both of them may
be set. An implementing class should know how to handle this.
The general contract is as follows: if the
Dependency.CONTEXT_ITEM
bit is set in the bit field returned by Expression.getDependencies()
, the eval method will
be called once for every item in the context sequence. The contextItem
parameter will be set to the current item. Otherwise, the eval method will only be called
once for the whole context sequence and contextItem will be null.
eXist tries to process the entire context set in one, single step whenever
possible. Thus, most classes only expect context to contain a list of
nodes which represents the current context of the expression.
The position() function in XPath is an example for an expression,
which requires both, context sequence and context item to be set.
The context sequence might be a node set, a sequence of atomic values or a single
node or atomic value.
- Specified by:
eval
in interface Expression
- Specified by:
eval
in class Function
- Throws:
XPathException
returnsType
public int returnsType()
- Description copied from interface:
Expression
- The static return type of the expression.
This method should return one of the type constants defined in class
Type
. If the return type cannot be determined
statically, return Type.ITEM.
- Specified by:
returnsType
in interface Expression
- Overrides:
returnsType
in class Function
Copyright (C) Wolfgang Meier. All rights reserved.