info.magnolia.module.rssaggregator.util
Class MagnoliaTemplate

java.lang.Object
  info.magnolia.module.rssaggregator.util.MagnoliaTemplate

All Implemented Interfaces:

MagnoliaQueryOperations

public class MagnoliaTemplate
extends Object
implements MagnoliaQueryOperations

Convenience class to simplify use of Magnolia queries and the mapping of their results to types.

Note that all queries performed by this class are logged at DEBUG level for convenient debugging when necessary.

Author:

Rob van der Linden Vooren

See Also:

ContentMapper

Field Summary

protected org.slf4j.Logger

logger Logger for this instance.

Constructor Summary

MagnoliaTemplate()

Method Summary

protected <T> Collection<T>	doExceptionThrowingQuery(String repository, String query, String language, String type)
protected <T> List<T>	query(String repository, String query, String language, String type, ContentMapper<T> mapper)
<T> List<T>	queryForList(String repository, String query, String language, String type, ContentMapper<T> mapper) Execute a query for a result list of type T, for the given query.
<T> T	queryForObject(String repository, String query, String language, String type, ContentMapper<T> mapper) Execute a query for a single or null result object, for the given query.
protected <T> Collection<T>	queryInternal(String repository, String query, String language, String type) Performs the actual query execution.
protected static <T> T	singleResult(Collection<T> results) Return a single result object from the given collection or null if the collection is empty or null.
javax.jcr.Node	xpathQueryForContent(String repository, String query, String type) Execute an XPath query for a Content node.
<T> List<T>	xpathQueryForList(String repository, String query, String type, ContentMapper<T> mapper) Execute an XPath query for a result list of type T, for the given query.
<T> T	xpathQueryForObject(String repository, String query, String type, ContentMapper<T> mapper) Execute an XPath query for a single or null result object, for the given query.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected org.slf4j.Logger logger

Logger for this instance.

Constructor Detail

MagnoliaTemplate

public MagnoliaTemplate()

Method Detail

queryForList

public <T> List<T> queryForList(String repository,
                                String query,
                                String language,
                                String type,
                                ContentMapper<T> mapper)

Execute a query for a result list of type T, for the given query.

Specified by:

queryForList in interface MagnoliaQueryOperations

Parameters:

repository - the repository to execute query against

query - query to execute

language - query language (either XPATH or SQL).

type - the type of the item to query for

mapper - the mapper used

Returns:

the result object of the required type, or null in case of a null query

queryForObject

public <T> T queryForObject(String repository,
                            String query,
                            String language,
                            String type,
                            ContentMapper<T> mapper)

Execute a query for a single or null result object, for the given query.

This method is useful for running queries with a known outcome. The query is expected to be a single result query; the returned result will be directly mapped to the corresponding object type.

Specified by:

queryForObject in interface MagnoliaQueryOperations

Parameters:

repository - the repository to execute query against

query - query to execute

language - query language (either XPATH or SQL).

type - the type of the item to query for

mapper - the mapper used

Returns:

the result object of the required type, or null in case of a null query

xpathQueryForList

public <T> List<T> xpathQueryForList(String repository,
                                     String query,
                                     String type,
                                     ContentMapper<T> mapper)
                          throws DataAccessException

Execute an XPath query for a result list of type T, for the given query.

Specified by:

xpathQueryForList in interface MagnoliaQueryOperations

Parameters:

repository - the repository to execute query against

query - query to execute

type - the type of the item to query for

mapper - the mapper used

Returns:

the result object of the required type, or null in case of a null Xpath query

Throws:

DataAccessException - if there is any problem executing the query

xpathQueryForObject

public <T> T xpathQueryForObject(String repository,
                                 String query,
                                 String type,
                                 ContentMapper<T> mapper)
                      throws DataAccessException

Execute an XPath query for a single or null result object, for the given query.

This method is useful for running queries with a known outcome. The query is expected to be a single result query; the returned result will be directly mapped to the corresponding object type.

Specified by:

xpathQueryForObject in interface MagnoliaQueryOperations

Parameters:

repository - the repository to execute query against

query - query to execute

type - the type of the item to query for

mapper - the mapper used

Returns:

the result object of the required type, or null in case of a null query

Throws:

IncorrectResultSizeDataAccessException - if the query returns more than one results

DataAccessException - if there is any problem executing the query

xpathQueryForContent

public javax.jcr.Node xpathQueryForContent(String repository,
                                           String query,
                                           String type)
                                    throws DataAccessException

Execute an XPath query for a Content node.

Specified by:

xpathQueryForContent in interface MagnoliaQueryOperations

Parameters:

repository - the repository to execute query against

query - query to execute

type - the type of the item to query for

Returns:

the result Content node, or null if no such node exists

Throws:

DataAccessException - if there is any problem executing the query

query

protected <T> List<T> query(String repository,
                            String query,
                            String language,
                            String type,
                            ContentMapper<T> mapper)
                 throws DataAccessException

Throws:

DataAccessException

queryInternal

protected <T> Collection<T> queryInternal(String repository,
                                          String query,
                                          String language,
                                          String type)

Performs the actual query execution. Purposely delegates to QueryUtil.exceptionThrowingQuery(..) in order to provide flexibility with regards to error handling, by translating any RepositoryException into an unchecked DataAccessException. This allows for optional exception handling and logging, making it a better alternative then using QueryUtil.query(..) directly, which logs the error and then directly swallows the exception. Execute a query for a result list of type T, for the given query.

Parameters:

repository - the repository to execute query against

query - query to execute

language - query language (either or ).

type - the type of the item to query for

Returns:

the result object of the required type, or null in case of a null query

Throws:

DataAccessException - if there is any problem executing the query

doExceptionThrowingQuery

protected <T> Collection<T> doExceptionThrowingQuery(String repository,
                                                     String query,
                                                     String language,
                                                     String type)
                                          throws javax.jcr.RepositoryException

Throws:

javax.jcr.RepositoryException

singleResult

protected static <T> T singleResult(Collection<T> results)
                         throws IncorrectResultSizeDataAccessException

Return a single result object from the given collection or null if the collection is empty or null.

Parameters:

results - the result collection (may be null)

Returns:

the single result object, or null when no result

Throws:

IncorrectResultSizeDataAccessException - if collection contains more than one element