org.datanucleus.store.mapped.mapping
Class NullMapping

java.lang.Object
  extended by org.datanucleus.store.mapped.mapping.JavaTypeMapping
      extended by org.datanucleus.store.mapped.mapping.SingleFieldMapping
          extended by org.datanucleus.store.mapped.mapping.NullMapping

public class NullMapping
extends SingleFieldMapping

Simple mapping for a null literal. Only used when the type is not determined


Field Summary
 
Fields inherited from class org.datanucleus.store.mapped.mapping.JavaTypeMapping
datastoreContainer, datastoreMappings, LOCALISER, mmd, referenceMapping, roleForMember, storeMgr, type
 
Constructor Summary
NullMapping(MappedStoreManager storeMgr)
           
 
Method Summary
 java.lang.Class getJavaType()
          Accessor for the java type being mapped.
 java.lang.Object getObject(ExecutionContext ec, java.lang.Object resultSet, int[] exprIndex)
          Obtains a value from datastoreResults at position specified by exprIndex.
 java.lang.Object getSampleValue(ClassLoaderResolver clr)
          Return a sample value of the mapping type to be used for internal evaluation of type/conversion.
 ScalarExpression newLiteral(QueryExpression qs, java.lang.Object value)
          Creates a literal from an value for use in TJDO-style JDOQL.
 ScalarExpression newScalarExpression(QueryExpression qs, LogicSetExpression te)
          Creates a expression from a field name/table.
 void setObject(ExecutionContext ec, java.lang.Object preparedStatement, int[] exprIndex, java.lang.Object value)
          Sets a value into datastoreStatement at position specified by exprIndex.
 
Methods inherited from class org.datanucleus.store.mapped.mapping.SingleFieldMapping
equals, getBoolean, getByte, getChar, getDefaultLength, getDouble, getFloat, getInt, getJavaTypeForDatastoreMapping, getLong, getShort, getString, getValidValues, initialize, prepareDatastoreMapping, setBoolean, setByte, setChar, setDouble, setFloat, setInt, setLong, setShort, setString
 
Methods inherited from class org.datanucleus.store.mapped.mapping.JavaTypeMapping
addDatastoreMapping, failureMessage, getColumnMetaDataForMember, getDatastoreContainer, getDatastoreMapping, getDatastoreMappings, getMemberMetaData, getNumberOfDatastoreMappings, getObject, getReferenceMapping, getRoleForMember, getType, getValueForDatastoreMapping, hashCode, hasSimpleDatastoreRepresentation, includeInFetchStatement, includeInInsertStatement, includeInUpdateStatement, initialize, isNullable, isSerialised, setDatastoreContainer, setDefault, setMemberMetaData, setObject, setReferenceMapping, setRoleForMember
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

NullMapping

public NullMapping(MappedStoreManager storeMgr)
Method Detail

getJavaType

public java.lang.Class getJavaType()
Description copied from class: JavaTypeMapping
Accessor for the java type being mapped. This is the java type that the mapping represents. Some examples : The "java type" is the java-type name used in the plugin.xml mapping file

Specified by:
getJavaType in class JavaTypeMapping
Returns:
The java type

getObject

public java.lang.Object getObject(ExecutionContext ec,
                                  java.lang.Object resultSet,
                                  int[] exprIndex)
Description copied from class: JavaTypeMapping
Obtains a value from datastoreResults at position specified by exprIndex.

Overrides:
getObject in class SingleFieldMapping
Parameters:
ec - ExecutionContext
resultSet - an object returned from the datastore with values
exprIndex - the position of the value in the result
Returns:
the value

setObject

public void setObject(ExecutionContext ec,
                      java.lang.Object preparedStatement,
                      int[] exprIndex,
                      java.lang.Object value)
Description copied from class: JavaTypeMapping
Sets a value into datastoreStatement at position specified by exprIndex.

Overrides:
setObject in class SingleFieldMapping
Parameters:
ec - ExecutionContext
preparedStatement - a datastore object that executes statements in the database
exprIndex - the position of the value in the statement
value - the value

getSampleValue

public java.lang.Object getSampleValue(ClassLoaderResolver clr)
Description copied from class: JavaTypeMapping
Return a sample value of the mapping type to be used for internal evaluation of type/conversion. TODO Delete when we drop legacy support

Overrides:
getSampleValue in class JavaTypeMapping
Parameters:
clr - ClassLoader resolver
Returns:
The sample value.

newLiteral

public ScalarExpression newLiteral(QueryExpression qs,
                                   java.lang.Object value)
Description copied from class: JavaTypeMapping
Creates a literal from an value for use in TJDO-style JDOQL. This implementation just throws a NucleusException.

Overrides:
newLiteral in class JavaTypeMapping
Parameters:
qs - The Query statement
value - The object
Returns:
A Scalar Expression TODO Remove this when we drop legacy query mechanism

newScalarExpression

public ScalarExpression newScalarExpression(QueryExpression qs,
                                            LogicSetExpression te)
Description copied from class: JavaTypeMapping
Creates a expression from a field name/table. e.g. tablename.fieldname; tablealias.fieldalias For use in TJDO-style JDOQL. This implementation just throws a NucleusException.

Overrides:
newScalarExpression in class JavaTypeMapping
Parameters:
qs - The Query statement
te - the alias for the table
Returns:
A Scalar Expression TODO Remove this when we drop legacy query mechanism


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