org.datanucleus.store.rdbms.query

Class ResultClassROF

java.lang.Object

org.datanucleus.store.rdbms.query.ResultClassROF

All Implemented Interfaces:

ResultObjectFactory

public class ResultClassROF
extends Object
implements ResultObjectFactory

Take a ResultSet, and for each row retrieves an object of a specified type. Follows the rules in JDO2 spec [14.6.12] regarding the result class.

The resultClass will be used to create objects of that type when calling getObject(). The resultClass can be one of the following

• Simple type - String, Long, Integer, Float, Boolean, Byte, Character, Double, Short, BigDecimal, BigInteger, java.util.Date, java.sql.Date, java.sql.Time, java.sql.Timestamp
• java.util.Map - the JDO impl will choose the concrete impl of java.util.Map to use
• Object[]
• User defined type with either a constructor taking the result set fields, or a default constructor and setting the fields using a put(Object,Object) method, setXXX methods, or public fields

Objects of this class are created in 2 distinct situations. The first is where a candidate class is available, and consequently field position mappings are available. The second is where no candidate class is available and so only the field names are available, and the results are taken in ResultSet order. These 2 modes have their own constructor.

Constructor Summary

Constructors

Constructor and Description
ResultClassROF(RDBMSStoreManager storeMgr, Class cls, StatementClassMapping classDefinition) Constructor for a resultClass object factory where we have no result clause specified but a result class.
ResultClassROF(RDBMSStoreManager storeMgr, Class cls, StatementResultMapping resultDefinition) Constructor for a resultClass object factory where we have a result clause specified.
ResultClassROF(RDBMSStoreManager storeMgr, Class cls, String[] resultFieldNames) Constructor for cases where we have no candidate class and so have no mapping information to base field positions on.

Method Summary

Modifier and Type	Method and Description
Object	getObject(org.datanucleus.ExecutionContext ec, ResultSet rs) Method to convert the ResultSet row into an Object of the ResultClass type.
protected Object	getValueForNewObject(StatementNewObjectMapping newMap, org.datanucleus.ExecutionContext ec, ResultSet rs) Convenience method to return the value of a NewObject mapping for the current row of the provided query results.

Methods inherited from class java.lang.Object

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

Constructor Detail

ResultClassROF

public ResultClassROF(RDBMSStoreManager storeMgr,
                      Class cls,
                      StatementResultMapping resultDefinition)

Constructor for a resultClass object factory where we have a result clause specified.

Parameters:

storeMgr - RDBMS StoreManager

cls - The result class to use (if any)

resultDefinition - The mapping information for the result expressions

ResultClassROF

public ResultClassROF(RDBMSStoreManager storeMgr,
                      Class cls,
                      StatementClassMapping classDefinition)

Constructor for a resultClass object factory where we have no result clause specified but a result class. In this case the result will match the candidate class, but may not be the actual candidate class (e.g Object[])

Parameters:

storeMgr - RDBMS StoreManager

cls - The result class to use

classDefinition - The mapping information for the (candidate) class

ResultClassROF

public ResultClassROF(RDBMSStoreManager storeMgr,
                      Class cls,
                      String[] resultFieldNames)

Constructor for cases where we have no candidate class and so have no mapping information to base field positions on. The fields will be retrieved in the ResultSet order. Used for SQL queries.

Parameters:

storeMgr - RDBMS StoreManager

cls - The result class to use

resultFieldNames - Names for the result fields

Method Detail

getObject

public Object getObject(org.datanucleus.ExecutionContext ec,
                        ResultSet rs)

Method to convert the ResultSet row into an Object of the ResultClass type. We have a special handling for "result" expressions when they include literals or "new Object()" expression due to the fact that complex literals and "new Object()" cannot be added to the SQL queries.

Specified by:

getObject in interface ResultObjectFactory

Parameters:

ec - execution context

rs - The ResultSet from the Query.

Returns:

The ResultClass object.

getValueForNewObject

protected Object getValueForNewObject(StatementNewObjectMapping newMap,
                                      org.datanucleus.ExecutionContext ec,
                                      ResultSet rs)

Convenience method to return the value of a NewObject mapping for the current row of the provided query results.

Parameters:

newMap - new object mapping

ec - ExecutionContext

rs - Query results

Returns:

The value of the new object