Package org.apache.commons.jexl3

Class JxltEngine

java.lang.Object

org.apache.commons.jexl3.JxltEngine

public abstract class JxltEngine
extends Object

A simple "JeXL Template" engine.

At the base is an evaluator similar to the Unified EL evaluator used in JSP/JSF based on JEXL. At the top is a template engine inspired by Velocity that uses JEXL (instead of OGNL/VTL) as the scripting language.

The evaluator is intended to be used in configuration modules, XML based frameworks or JSP taglibs and facilitate the implementation of expression evaluation.

The template engine is intended to output any form of text; html, XML, CSV...

Since:

3.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	JxltEngine.Exception	The sole type of (runtime) exception the JxltEngine can throw.
static interface	JxltEngine.Expression	A unified expression that can mix immediate, deferred and nested sub-expressions as well as string constants; The "immediate" syntax is of the form "...${jexl-expr}..." The "deferred" syntax is of the form "...#{jexl-expr}..." The "nested" syntax is of the form "...#{...${jexl-expr0}...}..." The "composite" syntax is of the form "...${jexl-expr0}...

Constructor Summary

Constructors

Constructor	Description
JxltEngine()

Method Summary

Modifier and Type	Method	Description
abstract void	clearCache()	Clears the cache.
JxltEngine.Expression	createExpression(String expression)	Creates a JxltEngine.Expression from an expression string.
abstract JxltEngine.Expression	createExpression(JexlInfo info, String expression)	Creates a JxltEngine.Expression from an expression string.
JxltEngine.Template	createTemplate(String source)	Creates a new template.
JxltEngine.Template	createTemplate(String prefix, Reader source, String... parms)	Creates a new template.
JxltEngine.Template	createTemplate(String source, String... parms)	Creates a new template.
JxltEngine.Template	createTemplate(JexlInfo info, String source)	Creates a new template.
abstract JxltEngine.Template	createTemplate(JexlInfo info, String prefix, Reader source, String... parms)	Creates a new template.
JxltEngine.Template	createTemplate(JexlInfo info, String source, String... parms)	Creates a new template.
abstract JexlEngine	getEngine()	Gets the JexlEngine underlying this template engine.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

JxltEngine

public JxltEngine()

Method Details

clearCache

public abstract void clearCache()

Clears the cache.

createExpression

public abstract JxltEngine.Expression createExpression(JexlInfo info,
 String expression)

Creates a JxltEngine.Expression from an expression string. Uses and fills up the expression cache if any.

If the underlying JEXL engine is silent, errors will be logged through its logger as warnings.

Parameters:

info - the JexlInfo source information

expression - the JxltEngine.Template string expression

Returns:

the JxltEngine.Expression, null if silent and an error occurred

Throws:

JxltEngine.Exception - if an error occurs and the JexlEngine is not silent

createExpression

public JxltEngine.Expression createExpression(String expression)

Creates a JxltEngine.Expression from an expression string. Uses and fills up the expression cache if any.

If the underlying JEXL engine is silent, errors will be logged through its logger as warnings.

Parameters:

expression - the JxltEngine.Template string expression

Returns:

the JxltEngine.Expression, null if silent and an error occurred

Throws:

JxltEngine.Exception - if an error occurs and the JexlEngine is not silent

createTemplate

public JxltEngine.Template createTemplate(JexlInfo info,
 String source)

Creates a new template.

Parameters:

info - the source info

source - the source

Returns:

the template

createTemplate

public abstract JxltEngine.Template createTemplate(JexlInfo info,
 String prefix,
 Reader source,
 String... parms)

Creates a new template.

Parameters:

info - the jexl info (file, line, column)

prefix - the directive prefix

source - the source

parms - the parameter names

Returns:

the template

createTemplate

public JxltEngine.Template createTemplate(JexlInfo info,
 String source,
 String... parms)

Creates a new template.

Parameters:

info - the source info

parms - the parameter names

source - the source

Returns:

the template

createTemplate

public JxltEngine.Template createTemplate(String source)

Creates a new template.

Parameters:

source - the source

Returns:

the template

createTemplate

public JxltEngine.Template createTemplate(String prefix,
 Reader source,
 String... parms)

Creates a new template.

Parameters:

prefix - the directive prefix

source - the source

parms - the parameter names

Returns:

the template

createTemplate

public JxltEngine.Template createTemplate(String source,
 String... parms)

Creates a new template.

Parameters:

source - the source

parms - the parameter names

Returns:

the template

getEngine

public abstract JexlEngine getEngine()

Gets the JexlEngine underlying this template engine.

Returns:

the JexlEngine