com.hazelcast.query.extractor

Class ValueReader

java.lang.Object

com.hazelcast.query.extractor.ValueReader

Direct Known Subclasses:

DefaultPortableReader

public abstract class ValueReader
extends Object

Enables reading the value of the attribute specified by the path

The path may be:

1. simple -> it includes a single attribute only, like "name"
2. nested -> it includes more than a single attribute separated with a dot (.), e.g. "person.address.city"

The path may also include array elements:

1. specific quantifier, like "person.leg[1]" -> returns the leg with index 1
2. wildcard quantifier, like "person.leg[any]" -> returns all legs

The wildcard quantifier may be used multiple times, like "person.leg[any].finger[any]" which returns all fingers from all legs.

Constructor Summary

Constructors

Constructor and Description
ValueReader()

Method Summary

Modifier and Type	Method and Description
abstract <T> void	read(String path, ValueCallback<T> callback) Read the value of the attribute specified by the path and returns the result via the callback.
abstract <T> void	read(String path, ValueCollector<T> collector) Read the value of the attribute specified by the path and returns the result directly to the collector.

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueReader

public ValueReader()

Method Detail

read

public abstract <T> void read(String path,
                              ValueCallback<T> callback)
                       throws ValueReadingException

Read the value of the attribute specified by the path and returns the result via the callback.

Type Parameters:

T - Type of the value to read

Parameters:

path - attribute to read the value from

callback - callback to call with the value. May be called more than once in case of wildcards.

Throws:

ValueReadingException - in case of any reading errors. If an exception occurs the callback won't be called at all

read

public abstract <T> void read(String path,
                              ValueCollector<T> collector)
                       throws ValueReadingException

Read the value of the attribute specified by the path and returns the result directly to the collector.

Type Parameters:

T - Type of the value to read

Parameters:

path - attribute to read the value from

collector - collector to collect the result with. May collect more than one result in case of wildcards.

Throws:

ValueReadingException - in case of any reading errors. If an exception occurs the collector won't be called at all