Package com.hazelcast.query.extractor

Interface ValueReader

  • public interface ValueReader
    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.

    • Method Summary

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

    • Method Detail

      • read

        <T> void read​(java.lang.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

        <T> void read​(java.lang.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