org.apache.commons.jelly.expression
Class ExpressionSupport
java.lang.Object
|
+--org.apache.commons.jelly.expression.ExpressionSupport
- All Implemented Interfaces:
- Expression
- Direct Known Subclasses:
- CompositeExpression, ConstantExpression, JexlExpression, XPathExpression
- public abstract class ExpressionSupport
- extends java.lang.Object
- implements Expression
ExpressionSupport
an abstract base class for Expression implementations
which provides default implementations of some of the
typesafe evaluation methods.
- Version:
- $Revision: 1.15 $
- Author:
- James Strachan
Method Summary |
boolean |
evaluateAsBoolean(JellyContext context)
Evaluates the expression with the given context
coercing the result to be a boolean. |
java.util.Iterator |
evaluateAsIterator(JellyContext context)
Evaluates the expression with the given context
coercing the result to be an Iterator. |
java.lang.String |
evaluateAsString(JellyContext context)
Evaluates the expression with the given context
coercing the result to be a String. |
java.lang.Object |
evaluateRecurse(JellyContext context)
This method evaluates the expression until a value (a non-Expression) object
is returned. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
EMPTY_ITERATOR
protected static final java.util.Iterator EMPTY_ITERATOR
ExpressionSupport
public ExpressionSupport()
evaluateAsString
public java.lang.String evaluateAsString(JellyContext context)
- Description copied from interface:
Expression
- Evaluates the expression with the given context
coercing the result to be a String.
- Specified by:
evaluateAsString
in interface Expression
evaluateRecurse
public java.lang.Object evaluateRecurse(JellyContext context)
- Description copied from interface:
Expression
- This method evaluates the expression until a value (a non-Expression) object
is returned.
If the expression returns another expression, then the nested expression is evaluated.
Sometimes when Jelly is used inside Maven the value
of an expression can actually be another expression.
For example if a properties file is read, the values of variables
can actually be expressions themselves.
e.g. ${foo.bar} can lookup "foo.bar" in a Maven context
which could actually be another expression.
So using this method, nested expressions can be evaluated to the
actual underlying value object.
- Specified by:
evaluateRecurse
in interface Expression
evaluateAsBoolean
public boolean evaluateAsBoolean(JellyContext context)
- Description copied from interface:
Expression
- Evaluates the expression with the given context
coercing the result to be a boolean.
- Specified by:
evaluateAsBoolean
in interface Expression
evaluateAsIterator
public java.util.Iterator evaluateAsIterator(JellyContext context)
- Description copied from interface:
Expression
- Evaluates the expression with the given context
coercing the result to be an Iterator.
- Specified by:
evaluateAsIterator
in interface Expression
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