Package dev.morphia.aggregation.expressions

Class ArrayExpressions

  • public final class ArrayExpressions
extends Object
    Defines helper methods for the array expressions
    Since:
    2.0

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static dev.morphia.aggregation.expressions.impls.ArrayExpression array​(dev.morphia.aggregation.expressions.impls.Expression... expressions)
      Creates an array of the given expressions.
      static dev.morphia.aggregation.expressions.impls.ArrayExpression array​(Object... objects)
      Creates an array of the given objects.
      static dev.morphia.aggregation.expressions.impls.Expression arrayToObject​(dev.morphia.aggregation.expressions.impls.Expression array)
      Converts an array of key value pairs to a document.
      static dev.morphia.aggregation.expressions.impls.Expression concatArrays​(dev.morphia.aggregation.expressions.impls.Expression array, dev.morphia.aggregation.expressions.impls.Expression additional)
      Concatenates arrays to return the concatenated array.
      static dev.morphia.aggregation.expressions.impls.Expression elementAt​(dev.morphia.aggregation.expressions.impls.Expression array, dev.morphia.aggregation.expressions.impls.Expression index)
      Returns the element at the specified array index.
      static dev.morphia.aggregation.expressions.impls.ArrayFilterExpression filter​(dev.morphia.aggregation.expressions.impls.Expression array, dev.morphia.aggregation.expressions.impls.Expression conditional)
      Selects a subset of the array to return an array with only the elements that match the filter condition.
      static dev.morphia.aggregation.expressions.impls.Expression in​(dev.morphia.aggregation.expressions.impls.Expression search, dev.morphia.aggregation.expressions.impls.Expression array)
      Returns a boolean indicating whether a specified value is in an array.
      static dev.morphia.aggregation.expressions.impls.Expression indexOfArray​(dev.morphia.aggregation.expressions.impls.Expression array, dev.morphia.aggregation.expressions.impls.Expression search)
      Searches an array for an occurrence of a specified value and returns the array index of the first occurernce.
      static dev.morphia.aggregation.expressions.impls.Expression isArray​(dev.morphia.aggregation.expressions.impls.Expression array)
      Determines if the operand is an array.
      static dev.morphia.aggregation.expressions.impls.MapExpression map​(dev.morphia.aggregation.expressions.impls.Expression input, dev.morphia.aggregation.expressions.impls.Expression in)
      Applies a subexpression to each element of an array and returns the array of resulting values in order.
      static dev.morphia.aggregation.expressions.impls.Expression objectToArray​(dev.morphia.aggregation.expressions.impls.Expression array)
      Converts a document to an array of documents representing key-value pairs.
      static dev.morphia.aggregation.expressions.impls.RangeExpression range​(int start, int end)
      Outputs an array containing a sequence of integers according to user-defined inputs.
      static dev.morphia.aggregation.expressions.impls.Expression reduce​(dev.morphia.aggregation.expressions.impls.Expression input, dev.morphia.aggregation.expressions.impls.Expression initial, dev.morphia.aggregation.expressions.impls.Expression in)
      Applies an expression to each element in an array and combines them into a single value.
      static dev.morphia.aggregation.expressions.impls.Expression reverseArray​(dev.morphia.aggregation.expressions.impls.Expression array)
      Returns an array with the elements in reverse order.
      static dev.morphia.aggregation.expressions.impls.Expression size​(dev.morphia.aggregation.expressions.impls.Expression array)
      Counts and returns the total number of items in an array.
      static dev.morphia.aggregation.expressions.impls.Expression slice​(dev.morphia.aggregation.expressions.impls.Expression array, int size)
      Returns a subset of an array.
      static dev.morphia.aggregation.expressions.impls.Expression sortArray​(dev.morphia.aggregation.expressions.impls.Expression input, Sort... sort)
      Sorts an array based on its elements.
      static dev.morphia.aggregation.expressions.impls.ZipExpression zip​(dev.morphia.aggregation.expressions.impls.Expression... arrays)
      Merge two arrays together.

    • Method Detail

      • array

        public static dev.morphia.aggregation.expressions.impls.ArrayExpression array​(dev.morphia.aggregation.expressions.impls.Expression... expressions)
        Creates an array of the given expressions. This "expression" isn't so much a mongodb expression as it is a convenience method for building pipeline definitions.
        Parameters:
        expressions - the expressions
        Returns:
        the new expression

      • array

        @MorphiaExperimental
public static dev.morphia.aggregation.expressions.impls.ArrayExpression array​(Object... objects)
        Creates an array of the given objects. This method is an experiment in accepting a wider breadth of types and finding the expressions at encoding time and dealing with them appropriately. There might be bugs in this approach. This method might go away. But it's useful in some Morphia tests, at least.
        Parameters:
        objects - the objects
        Returns:
        the new expression
        Since:
        2.3
        Developer note.
        This is an experimental item. Its function and presence are subject to change. Feedback on features and usability extremely welcome.

      • arrayToObject

        public static dev.morphia.aggregation.expressions.impls.Expression arrayToObject​(dev.morphia.aggregation.expressions.impls.Expression array)
        Converts an array of key value pairs to a document.
        Parameters:
        array - the array to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $arrayToObject

      • concatArrays

        public static dev.morphia.aggregation.expressions.impls.Expression concatArrays​(dev.morphia.aggregation.expressions.impls.Expression array,
                                                                                dev.morphia.aggregation.expressions.impls.Expression additional)
        Concatenates arrays to return the concatenated array.
        Parameters:
        array - the array to use
        additional - any additional arrays to concatenate
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $concatArrays

      • elementAt

        public static dev.morphia.aggregation.expressions.impls.Expression elementAt​(dev.morphia.aggregation.expressions.impls.Expression array,
                                                                             dev.morphia.aggregation.expressions.impls.Expression index)
        Returns the element at the specified array index.
        Parameters:
        array - the array to use
        index - the index to return
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $arrayElemAt

      • filter

        public static dev.morphia.aggregation.expressions.impls.ArrayFilterExpression filter​(dev.morphia.aggregation.expressions.impls.Expression array,
                                                                                     dev.morphia.aggregation.expressions.impls.Expression conditional)
        Selects a subset of the array to return an array with only the elements that match the filter condition.
        Parameters:
        array - the array to use
        conditional - the conditional to use for filtering
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $filter

      • in

        public static dev.morphia.aggregation.expressions.impls.Expression in​(dev.morphia.aggregation.expressions.impls.Expression search,
                                                                      dev.morphia.aggregation.expressions.impls.Expression array)
        Returns a boolean indicating whether a specified value is in an array.
        Parameters:
        search - the expression to search for
        array - the array to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $in

      • indexOfArray

        public static dev.morphia.aggregation.expressions.impls.Expression indexOfArray​(dev.morphia.aggregation.expressions.impls.Expression array,
                                                                                dev.morphia.aggregation.expressions.impls.Expression search)
        Searches an array for an occurrence of a specified value and returns the array index of the first occurernce. If the substring is not found, returns -1.
        Parameters:
        array - the array to use
        search - the expression to search for
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $indexOfArray

      • isArray

        public static dev.morphia.aggregation.expressions.impls.Expression isArray​(dev.morphia.aggregation.expressions.impls.Expression array)
        Determines if the operand is an array. Returns a boolean.
        Parameters:
        array - the array to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $isArray

      • map

        public static dev.morphia.aggregation.expressions.impls.MapExpression map​(dev.morphia.aggregation.expressions.impls.Expression input,
                                                                          dev.morphia.aggregation.expressions.impls.Expression in)
        Applies a subexpression to each element of an array and returns the array of resulting values in order. Accepts named parameters.
        Parameters:
        input - the array to use
        in - An expression that is applied to each element of the input array.
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $map

      • objectToArray

        public static dev.morphia.aggregation.expressions.impls.Expression objectToArray​(dev.morphia.aggregation.expressions.impls.Expression array)
        Converts a document to an array of documents representing key-value pairs.
        Parameters:
        array - the array to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $objectToArray

      • range

        public static dev.morphia.aggregation.expressions.impls.RangeExpression range​(int start,
                                                                              int end)
        Outputs an array containing a sequence of integers according to user-defined inputs.
        Parameters:
        start - the starting value
        end - the ending value
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $range

      • reduce

        public static dev.morphia.aggregation.expressions.impls.Expression reduce​(dev.morphia.aggregation.expressions.impls.Expression input,
                                                                          dev.morphia.aggregation.expressions.impls.Expression initial,
                                                                          dev.morphia.aggregation.expressions.impls.Expression in)
        Applies an expression to each element in an array and combines them into a single value.
        Parameters:
        input - the array to use
        initial - The initial cumulative value set before in is applied to the first element of the input array.
        in - A valid expression that $reduce applies to each element in the input array in left-to-right order.
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $reduce

      • reverseArray

        public static dev.morphia.aggregation.expressions.impls.Expression reverseArray​(dev.morphia.aggregation.expressions.impls.Expression array)
        Returns an array with the elements in reverse order.
        Parameters:
        array - the array to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $reverseArray

      • size

        public static dev.morphia.aggregation.expressions.impls.Expression size​(dev.morphia.aggregation.expressions.impls.Expression array)
        Counts and returns the total number of items in an array.
        Parameters:
        array - the array to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $size

      • slice

        public static dev.morphia.aggregation.expressions.impls.Expression slice​(dev.morphia.aggregation.expressions.impls.Expression array,
                                                                         int size)
        Returns a subset of an array.
        Parameters:
        array - the array to use
        size - the number of elements to return
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $slice

      • sortArray

        public static dev.morphia.aggregation.expressions.impls.Expression sortArray​(dev.morphia.aggregation.expressions.impls.Expression input,
                                                                             Sort... sort)
        Sorts an array based on its elements. To sort by value, use Sort.naturalAscending() or Sort.naturalDescending(). See here for details.
        Parameters:
        input - the array to be sorted.
        sort - the sort order
        Returns:
        the new expression
        Since:
        2.3
        Since server release
        5.2
        MongoDB documentation
        Aggregration Expression: $sortArray

      • zip

        public static dev.morphia.aggregation.expressions.impls.ZipExpression zip​(dev.morphia.aggregation.expressions.impls.Expression... arrays)
        Merge two arrays together.
        Parameters:
        arrays - the arrays to use
        Returns:
        the new expression
        MongoDB documentation
        Aggregration Expression: $zip