Package org.apache.cayenne.query

Class Ordering

java.lang.Object
org.apache.cayenne.query.Ordering
All Implemented Interfaces:
Serializable, Comparator<Object>, XMLSerializable
public class Ordering extends Object implements Comparator<Object>, Serializable, XMLSerializable
Defines object sorting criteria, used either for in-memory sorting of object lists or as a specification for building ORDER BY clause of a SelectQuery query. Note that in case of in-memory sorting, Ordering can be used with any JavaBeans, not just DataObjects.
See Also:

  • Field Details

    • sortSpecString

      protected String sortSpecString

    • sortSpec

      protected transient Expression sortSpec

    • sortOrder

      protected SortOrder sortOrder

    • pathExceptionSuppressed

      protected boolean pathExceptionSuppressed

    • nullSortedFirst

      protected boolean nullSortedFirst

  • Constructor Details

    • Ordering

      public Ordering()

    • Ordering

      public Ordering(String sortPathSpec)
      Create an ordering instance with a provided path and ascending sorting strategy.
      Since:
      4.0

    • Ordering

      public Ordering(String sortPathSpec, SortOrder sortOrder)
      Since:
      3.0

    • Ordering

      public Ordering(Expression sortSpec)
      Since:
      4.0

    • Ordering

      public Ordering(Expression sortSpec, SortOrder sortOrder)
      Since:
      4.0

  • Method Details

    • orderList

      public static void orderList(List<?> objects, List<? extends Ordering> orderings)
      Orders a given list of objects, using a List of Orderings applied according the default iteration order of the Orderings list. I.e. each Ordering with lower index is more significant than any other Ordering with higher index. List being ordered is modified in place.
      Parameters:
      objects - elements to sort
      orderings - list of Orderings to be applied

    • orderedList

      public static <E> List<E> orderedList(Collection<E> objects, List<? extends Ordering> orderings)
      Orders a given list of objects, using a List of Orderings applied according the default iteration order of the Orderings list. I.e. each Ordering with lower index is more significant than any other Ordering with higher index.
      Parameters:
      objects - elements to sort
      orderings - list of Orderings to be applied
      Returns:
      new List with ordered elements
      Since:
      4.0

    • equals

      public boolean equals(Object object)
      Specified by:
      equals in interface Comparator<Object>
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • setSortSpecString

      public void setSortSpecString(String sortSpecString)
      Sets sortSpec to be an expression represented by string argument.
      Since:
      1.1

    • setNullSortedFirst

      public void setNullSortedFirst(boolean nullSortedFirst)
      Sets sort order for whether nulls are at the top or bottom of the resulting list. Default is true. Affects only in-memory sorting.
      Parameters:
      nullSortedFirst - true sorts nulls to the top of the list, false sorts nulls to the bottom

    • isNullSortedFirst

      public boolean isNullSortedFirst()
      Get sort order for nulls.
      Returns:
      true if nulls are sorted to the top of the list, false if sorted to the bottom

    • setPathExceptionSupressed

      public void setPathExceptionSupressed(boolean pathExceptionSuppressed)
      Sets whether a path with a null in the middle is ignored. For example, a sort from painting on artist.name would by default throw an exception if the artist was null. If set to true, then this is treated just like a null value. Default is false.
      Parameters:
      pathExceptionSuppressed - true to suppress exceptions and sort as null

    • isPathExceptionSuppressed

      public boolean isPathExceptionSuppressed()
      Is a path with a null in the middle is ignored.
      Returns:
      true is exception is suppressed and sorted as null

    • getSortSpecString

      public String getSortSpecString()
      Returns sortSpec string representation.
      Since:
      1.1

    • setSortOrder

      public void setSortOrder(SortOrder order)
      Sets the sort order for this ordering.
      Since:
      3.0

    • isAscending

      public boolean isAscending()
      Returns true if sorting is done in ascending order.

    • isDescending

      public boolean isDescending()
      Returns true if the sorting is done in descending order.
      Since:
      3.0

    • setAscending

      public void setAscending()
      If the sort order is DESCENDING or DESCENDING_INSENSITIVE, sets the sort order to ASCENDING or ASCENDING_INSENSITIVE, respectively.
      Since:
      3.0

    • setDescending

      public void setDescending()
      If the sort order is ASCENDING or ASCENDING_INSENSITIVE, sets the sort order to DESCENDING or DESCENDING_INSENSITIVE, respectively.
      Since:
      3.0

    • isCaseInsensitive

      public boolean isCaseInsensitive()
      Returns true if the sorting is case insensitive

    • isCaseSensitive

      public boolean isCaseSensitive()
      Returns true if the sorting is case sensitive.
      Since:
      3.0

    • setCaseInsensitive

      public void setCaseInsensitive()
      If the sort order is ASCENDING or DESCENDING, sets the sort order to ASCENDING_INSENSITIVE or DESCENDING_INSENSITIVE, respectively.
      Since:
      3.0

    • setCaseSensitive

      public void setCaseSensitive()
      If the sort order is ASCENDING_INSENSITIVE or DESCENDING_INSENSITIVE, sets the sort order to ASCENDING or DESCENDING, respectively.
      Since:
      3.0

    • getSortSpec

      public Expression getSortSpec()
      Returns the expression defining a ordering Java Bean property.

    • setSortSpec

      public void setSortSpec(Expression sortSpec)
      Sets the expression defining a ordering Java Bean property.

    • orderList

      public void orderList(List<?> objects)
      Orders the given list of objects according to the ordering that this object specifies. List is modified in-place.
      Parameters:
      objects - a List of objects to be sorted

    • orderedList

      public <E> List<E> orderedList(Collection<E> objects)
      Since:
      4.0

    • compare

      public int compare(Object o1, Object o2)
      Comparable interface implementation. Can compare two Java Beans based on the stored expression.
      Specified by:
      compare in interface Comparator<Object>

    • encodeAsXML

      public void encodeAsXML(XMLEncoder encoder, ConfigurationNodeVisitor delegate)
      Encodes itself as a query ordering.
      Specified by:
      encodeAsXML in interface XMLSerializable
      Since:
      1.1

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getSortOrder

      public SortOrder getSortOrder()
      Returns sort order for this ordering
      Since:
      3.1

    • then

      public Orderings then(Ordering nextOrdering)
      Returns Orderings with this Ordering followed by the provided next Ordering.
      Parameters:
      nextOrdering - the next Ordering to chain to this
      Returns:
      a new Orderings with both Ordering
      Since:
      4.1

    • then

      public Orderings then(Orderings nextOrderings)
      Returns Orderings with this Ordering followed by the provided list of next Orderings.
      Parameters:
      nextOrderings - the next Orderings to chain to this
      Returns:
      an array of sort orderings
      Since:
      4.1

    • then

      public Orderings then(List<Ordering> nextOrderings)
      Parameters:
      nextOrderings - the next Orderings to chain to this
      Returns:
      an array of sort orderings
      Since:
      4.1
      See Also: