com.googlecode.icegem.query.pagination
Class PaginatedQuery<V>

java.lang.Object
  com.googlecode.icegem.query.pagination.PaginatedQuery<V>

public class PaginatedQuery<V>
extends java.lang.Object

This component allows to execute paginated queries both from client and peer/server sides. It caches paginated query results in a help region and allows to iterate on them using paginated query API. See http://code.google.com/p/icegem/wiki/Documentation#Paginated_Query for more details and examples. RESTRICTIONS: 1). A query string for paginated query can be arbitrarily complex but entry key must be part of projection list. 2). For partitioned regions a query string must meet the requirements described in a GemFire documentation for querying partitioned regions. ORDER BY on Partitioned Regions A paginated query supports order by functionality on partitioned regions. The fields specified in the order by clause must be part of the projection list. Limiting of results: Paginated query result can be limited. By default this limit is 1000 entries. You can specify a custom limit value via paginated query constructors argument. If query results exceeds this limit: - only a specified limit number of entries will be cached and returned; - flag 'limitExceeded' will be set to 'true'. Examples: SELECT * FROM /data.keySet; SELECT DISTINCT d.key, d.value.field1 FROM /data.entrySet d ORDER BY d.value.field1;

Author:

Andrey Stepanov aka standy

Field Summary

static int	DEFAULT_PAGE_SIZE page size by default
static int	DEFAULT_QUERY_LIMIT Default limit on query result
static int	PAGE_NUMBER_FOR_GENERAL_INFO number of page that will be store general information about paginated query (e.g.
static java.lang.String	PAGINATED_QUERY_INFO_REGION_NAME name of a help region for storing information about paginated queries

Constructor Summary

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, int queryLimit, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, int queryLimit, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString, int pageSize)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, int queryLimit, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString, java.lang.Object[] queryParameters)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, int queryLimit, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString, java.lang.Object[] queryParameters, int pageSize)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString, int pageSize)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString, java.lang.Object[] queryParameters)
Creates a new PaginatedQuery instance.

PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService, com.gemstone.gemfire.cache.Region<java.lang.Object,V> region, java.lang.String queryString, java.lang.Object[] queryParameters, int pageSize)
Creates a new PaginatedQuery instance.

Method Summary

int	getPageSize() Returns size of page.
int	getTotalNumberOfEntries() Returns a total number of query entries.
int	getTotalNumberOfPages() Returns a total number of query pages.
boolean	isLimitExceeded() Gets value of a flag that indicates excess of query limit.
java.util.List<V>	page(int pageNumber) Returns entries for a specified page number.
boolean	pageExists(int pageNumber) Checks that a specified page number exists.
protected void	storePage(int pageNumber, java.util.List<java.lang.Object> page)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_PAGE_SIZE

public static final int DEFAULT_PAGE_SIZE

page size by default

See Also:

Constant Field Values

DEFAULT_QUERY_LIMIT

public static final int DEFAULT_QUERY_LIMIT

Default limit on query result

See Also:

Constant Field Values

PAGE_NUMBER_FOR_GENERAL_INFO

public static final int PAGE_NUMBER_FOR_GENERAL_INFO

number of page that will be store general information about paginated query (e.g. total number of query entries)

See Also:

Constant Field Values

PAGINATED_QUERY_INFO_REGION_NAME

public static final java.lang.String PAGINATED_QUERY_INFO_REGION_NAME

name of a help region for storing information about paginated queries

See Also:

Constant Field Values

Constructor Detail

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      int queryLimit,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

queryLimit - limit on query result

region - The region for querying.

queryString - query string that must return entry keys

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      int queryLimit,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString,
                      int pageSize)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

queryLimit - limit on query result

region - The region for querying.

queryString - query string that must return entry keys

pageSize - size of page

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      int queryLimit,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString,
                      java.lang.Object[] queryParameters)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

queryLimit - limit on query result

region - The region for querying.

queryString - query string that must return entry keys

queryParameters - parameters for query execution

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      int queryLimit,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString,
                      java.lang.Object[] queryParameters,
                      int pageSize)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

queryLimit - limit on query result

region - The region for querying.

queryString - query string that must return entry keys

queryParameters - parameters for query execution

pageSize - size of page

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

region - The region for querying

queryString - query string that must return entry keys

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString,
                      int pageSize)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

region - The region for querying.

queryString - query string that must return entry keys

pageSize - size of page

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString,
                      java.lang.Object[] queryParameters)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

region - The region for querying.

queryString - query string that must return entry keys

queryParameters - parameters for query execution

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

PaginatedQuery

public PaginatedQuery(com.gemstone.gemfire.cache.query.QueryService queryService,
                      com.gemstone.gemfire.cache.Region<java.lang.Object,V> region,
                      java.lang.String queryString,
                      java.lang.Object[] queryParameters,
                      int pageSize)
               throws com.gemstone.gemfire.cache.query.RegionNotFoundException

Creates a new PaginatedQuery instance.

Parameters:

queryService - The service to run the query.

region - The region for querying.

queryString - query string that must return entry keys

queryParameters - parameters for query execution

pageSize - size of page

Throws:

com.gemstone.gemfire.cache.query.RegionNotFoundException - when query region or help region were not founded

Method Detail

getPageSize

public int getPageSize()

Returns size of page.

Returns:

page size

getTotalNumberOfEntries

public int getTotalNumberOfEntries()
                            throws com.gemstone.gemfire.cache.query.QueryException

Returns a total number of query entries.

Returns:

total number of entries

Throws:

com.gemstone.gemfire.cache.query.QueryException - during query execution

getTotalNumberOfPages

public int getTotalNumberOfPages()
                          throws com.gemstone.gemfire.cache.query.QueryException

Returns a total number of query pages.

Returns:

total number of pages

Throws:

com.gemstone.gemfire.cache.query.QueryException - during query execution

isLimitExceeded

public boolean isLimitExceeded()
                        throws com.gemstone.gemfire.cache.query.QueryException

Gets value of a flag that indicates excess of query limit.

Returns:

boolean

Throws:

com.gemstone.gemfire.cache.query.QueryException - during query execution

page

public java.util.List<V> page(int pageNumber)
                       throws com.gemstone.gemfire.cache.query.QueryException

Returns entries for a specified page number. Use getTotalNumberOfPages() method to know how many pages this query has.

Parameters:

pageNumber - number of page to return

Returns:

List list of entries

Throws:

com.gemstone.gemfire.cache.query.QueryException - during query execution

pageExists

public boolean pageExists(int pageNumber)
                   throws com.gemstone.gemfire.cache.query.QueryException

Checks that a specified page number exists.

Parameters:

pageNumber - of type int

Returns:

boolean

Throws:

com.gemstone.gemfire.cache.query.QueryException - during query execution

storePage

protected void storePage(int pageNumber,
                         java.util.List<java.lang.Object> page)