org.datanucleus.store.mapped.expression
Class ClassExpression

java.lang.Object
  org.datanucleus.store.mapped.expression.ScalarExpression
      org.datanucleus.store.mapped.expression.ClassExpression

public class ClassExpression
extends ScalarExpression

An expression representing a class. This is used as follows :-

• JDOQL : access public static final fields. Here we invoke accessField on the ClassExpression.
• JDOQL : use the "instanceof" operator. Here we invoke instanceOf on an ObjectExpression pass in a ClassExpression
• JPQL : process the FROM candidates so each candidate is a ClassExpression. Here we set the join(s) for later processing

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.store.mapped.expression.ScalarExpression

ScalarExpression.DatastoreFieldExpression, ScalarExpression.DyadicOperator, ScalarExpression.ExpressionList, ScalarExpression.IllegalArgumentTypeException, ScalarExpression.IllegalOperationException, ScalarExpression.MethodInvocationException, ScalarExpression.MonadicOperator, ScalarExpression.Operator

Field Summary

Fields inherited from class org.datanucleus.store.mapped.expression.ScalarExpression

aliasIdentifier, checkForTypeAssignability, expressionList, FILTER, LOCALISER, lowestOperator, mapping, OP_ADD, OP_AND, OP_BETWEEN, OP_COM, OP_CONCAT, OP_DIV, OP_EQ, OP_GT, OP_GTEQ, OP_IN, OP_IS, OP_ISNOT, OP_LIKE, OP_LT, OP_LTEQ, OP_MOD, OP_MUL, OP_NEG, OP_NOT, OP_NOTEQ, OP_NOTIN, OP_NOTLIKE, OP_OR, OP_SUB, parameterName, PROJECTION, qs, st, te

Constructor Summary

ClassExpression(QueryExpression qs, java.lang.Class cls)
Constructor.

Method Summary

ScalarExpression	accessField(java.lang.String fieldName, boolean innerJoin) Method called when wanting to call public static final methods on the class.
java.lang.Class	getCls() Accessor for the class being represented.
JoinExpression[]	getJoins() Accessor for the join expression(s) for this class.
ScalarExpression	join(JoinExpression expr) Method to add a join expression for this class.

Methods inherited from class org.datanucleus.store.mapped.expression.ScalarExpression

add, and, as, assertValidTypeForParameterComparison, callMethod, cast, checkForTypeAssignability, com, div, encloseWithInParentheses, eor, eq, equals, getAlias, getConsistentTypeForParameterComparison, getExpressionList, getLogicSetExpression, getMapping, getNonAliasExpression, getQueryExpression, gt, gteq, in, instanceOf, ior, lt, lteq, mod, mul, neg, not, noteq, setParameterName, sub, toStatementText, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ClassExpression

public ClassExpression(QueryExpression qs,
                       java.lang.Class cls)

Constructor.

Parameters:

qs - The Query Statement

cls - The class

Method Detail

getCls

public java.lang.Class getCls()

Accessor for the class being represented.

Returns:

The class

accessField

public ScalarExpression accessField(java.lang.String fieldName,
                                    boolean innerJoin)

Method called when wanting to call public static final methods on the class.

Overrides:

accessField in class ScalarExpression

Parameters:

fieldName - Name of the public static final field

innerJoin - Not used

Returns:

Expression for the field access

join

public ScalarExpression join(JoinExpression expr)

Method to add a join expression for this class.

Parameters:

expr - Expression to join to

Returns:

This expression

getJoins

public JoinExpression[] getJoins()

Accessor for the join expression(s) for this class.

Returns:

Join expressions