Package com.caplin.jtm.persistence

Interface Persistence

public interface Persistence

Provides access to the Transformer persistence service.

If a module uses the persistence service any data persisted is saved over restarts of Transformer and - if a central database is used - is also available on multiple Transformers is they are clustered together.

Method Summary

Modifier and Type	Method	Description
Map<String,String>	call(String procedure, String[] args)	Calls a stored procedure in the persistence service
int	delete(String table, Map<String,String> selector)	Deletes entries from the persistence service given the provided selector
List<Map<String,String>>	get(String table, Map<String,String> selector)
List<Map<String,String>>	get(String table, Map<String,String> selector, long limit)
List<Map<String,String>>	get(String table, Map<String,String> selector, LinkedHashMap<String,Ordering> ordering)
List<Map<String,String>>	get(String table, Map<String,String> selector, LinkedHashMap<String,Ordering> ordering, long limit)	Gets entries from the persistence service given the provided selector
List<Map<String,String>>	query(String table, String query, QueryParams params)	Gets entries from the persistence service matching the provided query
int	upsert(String table, Map<String,String> keys, Map<String,String> data)	Updates or inserts an entry to be stored by the persistence service

Method Details

upsert

int upsert(String table,
 Map<String,String> keys,
 Map<String,String> data)
    throws PersistenceException

Updates or inserts an entry to be stored by the persistence service

Parameters:

table - The name of the table used for persistence

keys - keys The key value pairs are used for building the WHERE clause of the SQL query, where key='value' for each key-value pair.

data - Key value pairs representing the field names and their values to be set on the 'upsertion'

Returns:

The number of entries affected by the update / insertion

Throws:

PersistenceException - when the upsert fails

get

List<Map<String,String>> get(String table,
 Map<String,String> selector)
                      throws PersistenceException

Parameters:

selector - query(String, String, QueryParams)

table - query(String, String, QueryParams) limit defaults to 0 - no limit ordering defaults to null - no ordering

Returns:

query(String, String, QueryParams)

Throws:

PersistenceException - if the persistence get fails

See Also:

• get(String, Map, LinkedHashMap, long)

get

List<Map<String,String>> get(String table,
 Map<String,String> selector,
 long limit)
                      throws PersistenceException

Parameters:

table - query(String, String, QueryParams)

selector - query(String, String, QueryParams)

limit - query(String, String, QueryParams) ordering defaults to null - no ordering

Returns:

query(String, String, QueryParams)

Throws:

PersistenceException - if the persistence get fails

See Also:

• get(String, Map, LinkedHashMap, long)

get

List<Map<String,String>> get(String table,
 Map<String,String> selector,
 LinkedHashMap<String,Ordering> ordering)
                      throws PersistenceException

Parameters:

selector - query(String, String, QueryParams)

ordering - query(String, String, QueryParams)

table - query(String, String, QueryParams) limit defaults to 0 - no limit

Returns:

query(String, String, QueryParams)

Throws:

PersistenceException - if the persistence get fails

See Also:

• get(String, Map, LinkedHashMap, long)

get

List<Map<String,String>> get(String table,
 Map<String,String> selector,
 LinkedHashMap<String,Ordering> ordering,
 long limit)
                      throws PersistenceException

Gets entries from the persistence service given the provided selector

Parameters:

table - The name of the table used for persistence

selector - Key value pairs representing field names to field values. These are used for constructing the WHERE clause of the SELECT query, where the value for each given field name is matched against the field value.

ordering - LinkedMap specifying the ordering criteria for this query in priority order. First element returned via iterating over this map represents the primary sort column. Null for database sort order.

limit - Limits the number of rows returned by this query. The first limit rows with respect to the sort order will be returned, 0 for no limit

Returns:

The rows matching the selector. This consists of a Java List of Maps. Each Map represents a row (key value pairs corresponding to field names and their values). The List is empty if no rows match the search query.

Throws:

PersistenceException - if the persistence get fails Note: This method is a convenience wrapper for query(String, String, QueryParams)

See Also:

• query(String, String, QueryParams)

query

List<Map<String,String>> query(String table,
 String query,
 QueryParams params)
                        throws PersistenceException

Gets entries from the persistence service matching the provided query

Parameters:

table - The name of the table used for persistence

query - Used as the predicate for the WHERE clause when constructing an SQL query. The query should be formatted as a JDBC Prepared Statement using '?' placeholders.

params - QueryParams to specify arguments to be bound to '?' characters in the query string, custom sort criteria and a 'limit' specifying the maximum number of rows to be returned

Returns:

The rows matching the selector. This consists of a Java List of Maps. Each Map represents a row (key value pairs corresponding to field names and their values). The List is empty if no rows match the search query.

Throws:

PersistenceException - if the persistence query fails.

delete

int delete(String table,
 Map<String,String> selector)
    throws PersistenceException

Deletes entries from the persistence service given the provided selector

Parameters:

table - The name of the table used for persistence

selector - Key value pairs representing field names to field values. These are used for constructing the WHERE clause of the SELECT query, where the value for each given field name is matched against the field value.

Returns:

The number of rows deleted

Throws:

PersistenceException - if the persistence delete fails.

call

Map<String,String> call(String procedure,
 String[] args)
                 throws PersistenceException

Calls a stored procedure in the persistence service

Parameters:

procedure - The name of the procedure to be called

args - An ordered list of input arguments to be provided as input parameters to the procedure call.

Returns:

The output parameters. Keys are always uppercase for DBMS independence.

Throws:

PersistenceException - if the procedure call fails.