Package io.openems.edge.common.channel.value

Class Value<T>

  • Type Parameters:
    T - the type of the value
    public class Value<T>
extends java.lang.Object
    It is important to understand, that a Channel Value could be UNDEFINED (i.e. 'null') at any point in time - e.g. due to lost communication connection to a Device or Service, or because the system is just starting up and does not yet have any data. This class wraps a 'value' information for a Channel and provides convenience methods for retrieving it.

    To get the actual value of a Channel using this object, typically one of the following methods will fit:

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.lang.String UNDEFINED_VALUE_STRING
      The String for UNDEFINED, i.e.

    • Constructor Summary

      Constructors 
      Constructor Description
      Value​(Channel<T> parent, T value)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      <O extends OptionsEnum>
      O      		 asEnum()
      Gets the value as its Enum option.
      com.google.gson.JsonElement asJson()
      Gets the value in GSON JSON format.
      java.util.Optional<T> asOptional()
      Gets the value as an Optional.
      java.lang.String asOptionString()
      Gets the value as its String option.
      java.lang.String asString()
      Gets the value as a formatted String with its unit.
      java.lang.String asStringWithoutUnit()
      Gets the value as a formatted String without its unit.
      T get()
      Gets the value or null.
      T getOrError()
      Gets the value or throws an Exception on null.
      java.time.LocalDateTime getTimestamp()
      Gets the timestamp when the value was created.
      boolean isDefined()
      Is the value defined?.
      T orElse​(T alternativeValue)
      Gets the value or the given alternativeValue.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • UNDEFINED_VALUE_STRING

        public static final java.lang.String UNDEFINED_VALUE_STRING
        The String for UNDEFINED, i.e. 'null' value channels.
        See Also:
        Constant Field Values

    • Constructor Detail

      • Value

        public Value​(Channel<T> parent,
             T value)

    • Method Detail

      • asString

        public java.lang.String asString()
        Gets the value as a formatted String with its unit. (Same as toString())
        Returns:
        the value as formatted String

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • asStringWithoutUnit

        public java.lang.String asStringWithoutUnit()
        Gets the value as a formatted String without its unit.
        Returns:
        formatted string without unit

      • get

        public T get()
        Gets the value or null.
        Returns:
        the value

      • asOptional

        public java.util.Optional<T> asOptional()
        Gets the value as an Optional.
        Returns:
        the value as Optional

      • isDefined

        public boolean isDefined()
        Is the value defined?. This is an abbreviation for Value.asOptional().isPresent().
        Returns:
        true if the value is defined; false if it is UNDEFINED

      • orElse

        public T orElse​(T alternativeValue)
        Gets the value or the given alternativeValue. This is short for '.asOptional().or()'.
        Parameters:
        alternativeValue - the alternative value
        Returns:
        the value; or an alternative value if the value is null

      • asOptionString

        public java.lang.String asOptionString()
        Gets the value as its String option. Enum options are converted to Strings.
        Returns:
        the String option of Enum values
        Throws:
        java.lang.IllegalArgumentException - no matching option existing

      • asEnum

        public <O extends OptionsEnum> O asEnum()
        Gets the value as its Enum option.
        Type Parameters:
        O - the OptionsEnum type
        Returns:
        the Enum value
        Throws:
        java.lang.IllegalArgumentException - no matching Enum option existing

      • asJson

        public com.google.gson.JsonElement asJson()
        Gets the value in GSON JSON format.
        Returns:
        the value as JsonElement

      • getTimestamp

        public java.time.LocalDateTime getTimestamp()
        Gets the timestamp when the value was created.
        Returns:
        the timestamp