ojb.broker.accesslayer
Class RowReaderDefaultImpl

java.lang.Object
  |
  +--ojb.broker.accesslayer.RowReaderDefaultImpl

All Implemented Interfaces:

RowReader, java.io.Serializable

Direct Known Subclasses:

RowReaderTestImpl

public class RowReaderDefaultImpl

extends java.lang.Object

implements RowReader

See Also:

Serialized Form

Constructor Summary

RowReaderDefaultImpl()

Method Summary

protected java.lang.Object	buildWithMultiArgsConstructor(ClassDescriptor cld, java.lang.Object[] row, java.lang.reflect.Constructor multiArgsConstructor)
protected java.lang.Object	buildWithReflection(ClassDescriptor cld, java.lang.Object[] row)
void	readObjectArrayFrom(java.sql.ResultSet rs, ClassDescriptor descriptor, java.lang.Object[] row) materialize a single object, described by cld, from the first row of the ResultSet rs.
java.lang.Object	readObjectFrom(java.lang.Object[] row, ClassDescriptor descriptor) materialize a single object, described by cld, from the first row of the ResultSet rs.
void	readPkValuesFrom(java.sql.ResultSet rs, ClassDescriptor cld, java.lang.Object[] row) Read primary key fields from the current ResultRow into the Object[] row.# ConversionStrategies are applied here!
protected ClassDescriptor	selectClassDescriptor(java.lang.Object[] row, ClassDescriptor cld)

Methods inherited from class java.lang.Object

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

Constructor Detail

RowReaderDefaultImpl

public RowReaderDefaultImpl()

Method Detail

readObjectFrom

public java.lang.Object readObjectFrom(java.lang.Object[] row,
                                       ClassDescriptor descriptor)
                                throws PersistenceBrokerException

materialize a single object, described by cld, from the first row of the ResultSet rs. There are two possible strategies: 1. The persistent class defines a public constructor with arguments matching the persistent primitive attributes of the class. In this case we build an array args of arguments from rs and call Constructor.newInstance(args) to build an object. 2. The persistent class does not provide such a constructor, but only a public default constructor. In this case we create an empty instance with Class.newInstance(). This empty instance is then filled by calling Field::set(obj,getObject(matchingColumn)) for each attribute. The second strategy needs n calls to Field::set() which are much more expensive than the filling of the args array in the first strategy. client applications should therefore define adequate constructors to benefit from performance gain of the first strategy.

Specified by:

readObjectFrom in interface RowReader

PersistenceBrokerException

readObjectArrayFrom

public void readObjectArrayFrom(java.sql.ResultSet rs,
                                ClassDescriptor descriptor,
                                java.lang.Object[] row)
                         throws PersistenceBrokerException

materialize a single object, described by cld, from the first row of the ResultSet rs. There are two possible strategies: 1. The persistent class defines a public constructor with arguments matching the persistent primitive attributes of the class. In this case we build an array args of arguments from rs and call Constructor.newInstance(args) to build an object. 2. The persistent class does not provide such a constructor, but only a public default constructor. In this case we create an empty instance with Class.newInstance(). This empty instance is then filled by calling Field::set(obj,getObject(matchingColumn)) for each attribute. The second strategy needs n calls to Field::set() which are much more expensive than the filling of the args array in the first strategy. client applications should therefore define adequate constructors to benefit from performance gain of the first strategy.

Specified by:

readObjectArrayFrom in interface RowReader

PersistenceBrokerException

selectClassDescriptor

protected ClassDescriptor selectClassDescriptor(java.lang.Object[] row,
                                                ClassDescriptor cld)
                                         throws PersistenceBrokerException

PersistenceBrokerException

buildWithReflection

protected java.lang.Object buildWithReflection(ClassDescriptor cld,
                                               java.lang.Object[] row)
                                        throws java.lang.InstantiationException,
                                               java.lang.IllegalAccessException,
                                               java.sql.SQLException

java.lang.InstantiationException

java.lang.IllegalAccessException

java.sql.SQLException

buildWithMultiArgsConstructor

protected java.lang.Object buildWithMultiArgsConstructor(ClassDescriptor cld,
                                                         java.lang.Object[] row,
                                                         java.lang.reflect.Constructor multiArgsConstructor)
                                                  throws java.sql.SQLException,
                                                         java.lang.InstantiationException,
                                                         java.lang.IllegalAccessException,
                                                         java.lang.reflect.InvocationTargetException,
                                                         PersistenceBrokerException

java.sql.SQLException

java.lang.InstantiationException

java.lang.IllegalAccessException

java.lang.reflect.InvocationTargetException

PersistenceBrokerException

readPkValuesFrom

public void readPkValuesFrom(java.sql.ResultSet rs,
                             ClassDescriptor cld,
                             java.lang.Object[] row)

Description copied from interface: RowReader

Read primary key fields from the current ResultRow into the Object[] row.# ConversionStrategies are applied here!

Specified by:

readPkValuesFrom in interface RowReader