org.jolokia.converter.json.simplifier

Class SimplifierExtractor<T>

java.lang.Object

org.jolokia.converter.json.simplifier.SimplifierExtractor<T>

All Implemented Interfaces:

Extractor

Direct Known Subclasses:

ClassSimplifier, DomElementSimplifier, FileSimplifier, ObjectNameSimplifier, UrlSimplifier

public abstract class SimplifierExtractor<T>
extends Object
implements Extractor

Base class for all simplifiers. A simplifier is a special Extractor which condense full blown Java beans (like File) to a more compact representation. Simplifier extractors cannot be written to and are only used for downstream serialization. Simplifier are registered by listing the classes in a META-INF/simplifiers plain text file and then picked up by the converter. The default simplifiers coming prepackaged are taken from META-INF/simplifiers-default

Since:

Jul 27, 2009

Author:

roland

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SimplifierExtractor.AttributeExtractor<T> Helper interface for extracting and simplifying values

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimplifierExtractor(Class<T> pType) Super constructor taking the value type as argument

Method Summary

Modifier and Type	Method and Description
protected void	addExtractor(String pName, SimplifierExtractor.AttributeExtractor<T> pExtractor) Add a single extractor
protected void	addExtractors(Object[][] pAttrExtractors) Add given extractors to the map.
boolean	canSetValue() No setting for simplifying extractors
Object	extractObject(ObjectToJsonConverter pConverter, Object pValue, Stack<String> pPathParts, boolean jsonify) Extract an object from pValue.
Class	getType() Type for which this extractor can objects of this type
Object	setObjectValue(StringToObjectConverter pConverter, Object pInner, String pAttribute, Object pValue) Throws always IllegalArgumentException since a simplifier cannot be written to

Methods inherited from class java.lang.Object

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

Constructor Detail

SimplifierExtractor

protected SimplifierExtractor(Class<T> pType)

Super constructor taking the value type as argument

Parameters:

pType - type for which this extractor is responsible

Method Detail

getType

public Class getType()

Type for which this extractor can objects of this type

Specified by:

getType in interface Extractor

Returns:

type which can be handled

extractObject

public Object extractObject(ObjectToJsonConverter pConverter,
                            Object pValue,
                            Stack<String> pPathParts,
                            boolean jsonify)
                     throws AttributeNotFoundException

Extract an object from pValue. In the simplest case, this is the value itself. For more complex data types, it is converted into a JSON structure if possible (and if 'jsonify' is true). pExtraArgs is not null, this returns only a substructure, specified by the path represented by this stack

Specified by:

extractObject in interface Extractor

Parameters:

pConverter - the global converter in order to be able do dispatch for serializing inner data types

pValue - the value to convert

pPathParts - extra arguments which contain e.g. a path

jsonify - whether to convert to a JSON object/list or whether the plain object should be returned. The later is required for writing an inner value

Returns:

the extracted object

Throws:

AttributeNotFoundException - if the inner path does not exist.

canSetValue

public boolean canSetValue()

No setting for simplifying extractors

Specified by:

canSetValue in interface Extractor

Returns:

always false

setObjectValue

public Object setObjectValue(StringToObjectConverter pConverter,
                             Object pInner,
                             String pAttribute,
                             Object pValue)
                      throws IllegalAccessException,
                             InvocationTargetException

Throws always IllegalArgumentException since a simplifier cannot be written to

Specified by:

setObjectValue in interface Extractor

Parameters:

pConverter - the global converter in order to be able do dispatch for serializing inner data types

pInner - object on which to set the value

pAttribute - attribute of the object to set

pValue - the new value to set

Returns:

the old value

Throws:

IllegalAccessException - if the attribute to set to is not accessible

InvocationTargetException - reflection error

addExtractors

protected final void addExtractors(Object[][] pAttrExtractors)

Add given extractors to the map. Should be called by a subclass from within init()

Parameters:

pAttrExtractors - extractors

addExtractor

protected final void addExtractor(String pName,
                                  SimplifierExtractor.AttributeExtractor<T> pExtractor)

Add a single extractor

Parameters:

pName - name of the extractor

pExtractor - the extractor itself