org.mule.module.json

Class JsonExpressionEvaluator

java.lang.Object

org.mule.expression.AbstractExpressionEvaluator

org.mule.module.json.JsonExpressionEvaluator

All Implemented Interfaces:

ExpressionEvaluator, NamedObject

Direct Known Subclasses:

JsonNodeExpressionEvaluator

public class JsonExpressionEvaluator
extends AbstractExpressionEvaluator

An expression evaluator to allow users to define json expressions in their mule configuration, i.e. #[json:person/addresses[0]/postcode]

See the JsonData object for mor information about the query syntax.

It is also possible to use this evaluator in ExpressionFilter objects. For example a filter could be defined as -

#[json:person/registered]

Where 'registered' is a boolean value. It is also possible to filter on the existence of a value i.e.

#[json:person/favouriteColour]

Which would return true if 'favouriteColour' has been set. This evaluator also dds two logic operators you can use to create more sophisticated boolean expressions; equals and not equals -

#[json:person/favouriteColour = red]

or

#[json:person/favouriteColour != brown]

See Also:

JsonData

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.commons.logging.Log	logger logger used by this class

Constructor Summary

Constructors

Constructor and Description
JsonExpressionEvaluator()

Method Summary

Methods

Modifier and Type	Method and Description
Object	evaluate(String expression, MuleMessage message) Extracts a single property from the message
protected Object	extractResultFromNode(org.codehaus.jackson.JsonNode result)
String	getName() Gets the name of the object

Methods inherited from class org.mule.expression.AbstractExpressionEvaluator

evaluateTyped

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final transient org.apache.commons.logging.Log logger

logger used by this class

Constructor Detail

JsonExpressionEvaluator

public JsonExpressionEvaluator()

Method Detail

evaluate

public Object evaluate(String expression,
              MuleMessage message)

Description copied from interface: ExpressionEvaluator

Extracts a single property from the message

Parameters:

expression - the property expression or expression

message - the message to extract from

Returns:

the result of the extraction or null if the property was not found

extractResultFromNode

protected Object extractResultFromNode(org.codehaus.jackson.JsonNode result)

getName

public String getName()

Description copied from interface: NamedObject

Gets the name of the object

Returns:

the name of the object