com.sap.tc.col.client.generic.api
Class SortingCriteria

java.lang.Object
  |
  +--com.sap.tc.col.client.generic.api.SortingCriteria

public class SortingCriteria

extends java.lang.Object

Defines the sort order for data contained in an aspect. The sort order is defined by specifing an indexed list of sorting crtieria. Criteria with lower indexes have higher priority. Each criterion defines a column of the aspect (by naming the field), a comparison rule that defines how data in that column is compared and a sorting direction that indicates whether lower values (with respect to the comparison rule) are listed before (ascending) or after (descending) higher values.

Data is sorted according to criterion 0 first. If two rows are equal with respect to the sorting rule of criterion 0, then these rows are sorted according to the sorting rule specified in criterion 1 and so on.

Backend implementations might add further criteria to guarantee a stable sort order. They can do this by forcing all key fields to be part of the sort order or by appending a sorting criterion for a unique row identifier (GUID, local row index etc.). Such additional sorting criteria are not expected to be visible through this class.

Note that it is allowed to define several criteria with the same field name. In the current implementation which supports only a single comparison rule (default rule) this makes no sense, but doesn't break the above definition. If in the future, several comparison rules might be supported, it makes perfectly sense to define several criteria (with differing rules) for the same field.

 Example usage:
 
  // create and define a sort order
  SortingCriteria sorting = new SortingCriteria();
  sorting.addCriterion("CUSTID", SortingCriteria.ASCENDING);
  sorting.addCriterion("CONNID", SortingCriteria.DESCENDING);
 
  IAspect bookings = aspect.getRelatedAspect("Bookings", sorting, LockMode.NONE);
  System.out.println(bookings.getSortingCriteria());
 

Expected usage in API: IAspect SortingCriteria getSortingCriteria(); IAspect getAspect(String aspectName, SortingCriteria sorting, LockMode lockMode); IAspect getRelatedAspect(String relationName, SortingCriteria sorting, LockMode lockMode); IAspectRow IAspect getRelatedAspect(String relationName, SortingCriteria sorting, LockMode lockMode); IQuery void setSortingCriteria(SortingCriteria sorting); // better way ???? IServiceModule IAspect getAspect(String aspectName, IKeyList keys, SortingCriteria sorting, LockMode lockMode);

Field Summary

static boolean	ASCENDING
static boolean	DESCENDING

Constructor Summary

SortingCriteria()

Method Summary

void	addCriterion(java.lang.String fieldName) Adds a new criterion at the end of the list (with lowest priority).
void	addCriterion(java.lang.String fieldName, boolean ascending) Adds a new criterion at the end of the list (with lowest priority).
java.lang.String	getComparisonRule(int i) Returnes the (currently unspecified) name of the comparison rule to be used or null if the (backend or data type defined) default comparison rule is to be used.
boolean	getDirection(int i) Returns true if the criterion with the given index defines ascending order, false for descending order.
java.lang.String	getFieldName(int i) Returns the name of the field that is sorted by the criterion with the given index.
void	removeCriterion(int i) Removes the criterion with the given index.
int	size() Returns the number of sorting criteria.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

ASCENDING

public static final boolean ASCENDING

DESCENDING

public static final boolean DESCENDING

Constructor Detail

SortingCriteria

public SortingCriteria()

Method Detail

size

public int size()

Returns the number of sorting criteria. A value of zero means that no sorting criteria have been defined. The implementation is allowed to ignore sort orders with size() == 0.

getFieldName

public java.lang.String getFieldName(int i)

Returns the name of the field that is sorted by the criterion with the given index.

Throws:

IndexOutOfBoundsException - if the index is not in the range 0 <= index < size().

getDirection

public boolean getDirection(int i)

Returns true if the criterion with the given index defines ascending order, false for descending order.

Throws:

IndexOutOfBoundsException - if the index is not in the range 0 <= index < size().

getComparisonRule

public java.lang.String getComparisonRule(int i)

Returnes the (currently unspecified) name of the comparison rule to be used or null if the (backend or data type defined) default comparison rule is to be used.

As of today, only the default comparison rule is supported. Therefore this method will always return null and there is no method to set a comparison rule.

In the future there might be support for other comparison rules, like

• binary (chars ar compared by their binary representation)
• lexical (lexical sort order, only defined for fields of type String)
• lexical-ignore-case (same as above, but ignoring case)
• number (by value, defined for fields with numeric types)
• day-of-week (sort strings according to the list Mo, Tu, We, ...
• month-of-year ... ...

Throws:

IndexOutOfBoundsException - if the index is not in the range 0 <= index < size().

addCriterion

public void addCriterion(java.lang.String fieldName)

Adds a new criterion at the end of the list (with lowest priority). The criterion is based on the field with the given name and the sort direction defaults to ASCENDING.

Throws:

IllegalArgumenException - if the fieldname is null or empty.

addCriterion

public void addCriterion(java.lang.String fieldName,
                         boolean ascending)

Adds a new criterion at the end of the list (with lowest priority). The criterion is based on the field with the given name and has the given sort direction.

Throws:

IllegalArgumenException - if the fieldname is null or empty.

removeCriterion

public void removeCriterion(int i)

Removes the criterion with the given index. All following criteria are moved to the next lower index postion, so SortingCriteria is always compact.

Throws:

IndexOutOfBoundsException - if the index is not in the range 0 <= index < size().

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object