Package dev.morphia.aggregation.experimental.expressions

Class Expressions

  • public final class Expressions
extends Object
    Defines helper methods for various expressions.
    Since:
    2.0

    • Method Detail

      • field

        public static Expression field​(String name)
        Creates a field expression for the given value. If the value does not already start with '$', it will be prepended automatically.
        Parameters:
        name - the field name
        Returns:
        the new expression

      • literal

        public static Expression literal​(Object value)
        Returns a value without parsing. Use for values that the aggregation pipeline may interpret as an expression.
        Parameters:
        value - the value
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $literal

      • meta

        public static Expression meta()
        Returns the metadata associated with a document in a pipeline operations, e.g. "textScore" when performing text search.
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $meta

      • of

        public static DocumentExpression of()
        Creates a new DocumentExpression.
        Returns:
        the new expression

      • toList

        public static <T> List<T> toList​(T first,
                                 T... additional)
        Type Parameters:
        T - the element type
        Parameters:
        first - the first item
        additional - additional items
        Returns:
        a list of them all
        Developer note.
        This is an internal item. Its function and presence are subject to change without warning. Its use is highly discouraged.

      • value

        public static Expression value​(Object value)
        Returns a value without parsing. Note that this is different from literal(Object) in that the given value will dropped directly in to the pipeline for use/evaluation in whatever context the value is used.
        Parameters:
        value - the value
        Returns:
        the new expression