org.apache.chemistry.opencmis.jcr.query

Class QueryTranslator

java.lang.Object

org.apache.chemistry.opencmis.jcr.query.QueryTranslator

public abstract class QueryTranslator
extends Object

Abstract base class for translating a CMIS query statement to a JCR XPath query statement. Overriding class need to implement methods for mapping CMIS ids to JCR paths, CMIS property names to JCR property names, CMIS type names to JCR type name and in addition a method for adding further constraints to a query based on a CMIS type.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	QueryTranslator(JcrTypeManager typeManager) Create a new query translator which uses the provided typeManager to resolve CMIS type names to CMIS types.

Method Summary

Methods

Modifier and Type	Method and Description
protected String	buildElementTest(TypeDefinition fromType) Build a XPath element test for the given CMIS type.
protected String	buildOrderByClause(TypeDefinition fromType, List<QueryObject.SortSpec> orderBys) Build a XPath order by clause for the given CMIS type and a list of QueryObject.SortSpecs.
protected String	buildPathExpression(TypeDefinition fromType, String folderPredicate) Build a XPath path expression for the CMIS type queried for and a folder predicate.
protected String	buildPredicates(TypeDefinition fromType, String condition) Build a XPath predicate for the given CMIS type and an additional condition.
QueryObject	getQueryObject()
protected abstract String	jcrPathFromCol(TypeDefinition fromType, String name) Map a column name in the CMIS query to the corresponding relative JCR path.
protected abstract String	jcrPathFromId(String id) Map a CMIS objectId to an absolute JCR path.
protected abstract String	jcrTypeCondition(TypeDefinition fromType) Create and additional condition in order for the query to only return nodes of the right type.
protected abstract String	jcrTypeName(TypeDefinition fromType) Map a CMIS type to the corresponding JCR type name.
String	translateToXPath(String statement) Translate a CMIS query statement to a JCR XPath query statement.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryTranslator

protected QueryTranslator(JcrTypeManager typeManager)

Create a new query translator which uses the provided typeManager to resolve CMIS type names to CMIS types.

Parameters:

typeManager -

Method Detail

getQueryObject

public QueryObject getQueryObject()

Returns:

the QueryObject from the last translation performed through translateToXPath(String).

translateToXPath

public String translateToXPath(String statement)

Translate a CMIS query statement to a JCR XPath query statement.

Parameters:

statement -

Returns:

jcrPathFromId

protected abstract String jcrPathFromId(String id)

Map a CMIS objectId to an absolute JCR path. This method is called to resolve the folder if of folder predicates (i.e. IN_FOLDER, IN_TREE).

Parameters:

id - objectId

Returns:

absolute JCR path corresponding to id.

jcrPathFromCol

protected abstract String jcrPathFromCol(TypeDefinition fromType,
                    String name)

Map a column name in the CMIS query to the corresponding relative JCR path. The path must be relative to the context node.

Parameters:

fromType - Type on which the CMIS query is performed

name - column name

Returns:

relative JCR path

jcrTypeName

protected abstract String jcrTypeName(TypeDefinition fromType)

Map a CMIS type to the corresponding JCR type name.

Parameters:

fromType - CMIS type

Returns:

name of the JCR type corresponding to fromType

See Also:

jcrTypeCondition(TypeDefinition)

jcrTypeCondition

protected abstract String jcrTypeCondition(TypeDefinition fromType)

Create and additional condition in order for the query to only return nodes of the right type. This condition and-ed to the condition determined by the CMIS query's where clause.

A CMIS query for non versionable documents should for example result in the following XPath query:

   element(*, nt:file)[not(@jcr:mixinTypes = 'mix:simpleVersionable')]
 

Here the element test is covered by jcrTypeName(TypeDefinition) while the predicate is covered by this method.

Parameters:

fromType -

Returns:

Additional condition or null if none.

See Also:

jcrTypeName(TypeDefinition)

buildPathExpression

protected String buildPathExpression(TypeDefinition fromType,
                         String folderPredicate)

Build a XPath path expression for the CMIS type queried for and a folder predicate.

Parameters:

fromType - CMIS type queried for

folderPredicate - folder predicate

Returns:

a valid XPath path expression or null if none.

buildElementTest

protected String buildElementTest(TypeDefinition fromType)

Build a XPath element test for the given CMIS type.

Parameters:

fromType - CMIS type queried for

Returns:

a valid XPath element test.

buildPredicates

protected String buildPredicates(TypeDefinition fromType,
                     String condition)

Build a XPath predicate for the given CMIS type and an additional condition. The additional condition should be and-ed to the condition resulting from evaluating fromType.

Parameters:

fromType - CMIS type queried for

condition - additional condition.

Returns:

a valid XPath predicate or null if none.

buildOrderByClause

protected String buildOrderByClause(TypeDefinition fromType,
                        List<QueryObject.SortSpec> orderBys)

Build a XPath order by clause for the given CMIS type and a list of QueryObject.SortSpecs.

Parameters:

fromType - CMIS type queried for

orderBys - SortSpecs

Returns:

a valid XPath order by clause