org.ujac.util.exi.type
Class BaseType

java.lang.Object
  org.ujac.util.exi.type.BaseType

All Implemented Interfaces:

ExpressionType

Direct Known Subclasses:

BaseDateType, BaseNumberType, BooleanType, ByteArrayType, CharArrayType, CharType, CollectionType, ConditionResultHolderType, DefaultType, DoubleArrayType, FloatArrayType, IntArrayType, LongArrayType, MapEntryType, MapType, NullValueType, ObjectArrayType, ResourceBundleType, RowType, ShortArrayType, StringType, TableType

public abstract class BaseType
extends Object
implements ExpressionType

Name: BaseType
Description: A base implementation for expression type handlers.

Author:

lauerc

Nested Class Summary

class	BaseType.EqualOperation The equal compare operation.
class	BaseType.InstanceofOperation The 'instanceof' operation.
class	BaseType.NotEqualOperation The 'not equal' compare operation.
class	BaseType.ObjectDefinedOperation Checks the existance of the given object.
class	BaseType.ObjectNotDefinedOperation Checks the existance of the given object.
class	BaseType.ToStringOperation Determines the textual representation of the given object.

Field Summary

protected ExpressionInterpreter	interpreter The expression interpreter.
protected Map	operations The operation map.

Constructor Summary

BaseType(ExpressionInterpreter interpreter)
Constructs a BaseType instace with specific attributes.

Method Summary

void	addOperation(String name, ExpressionOperation operation) Adds an operation.
Object	evalTuple(ExpressionTuple expr, ExpressionContext ctx) Evaluates the given expression tuple.
protected String	execToString(ExpressionTuple expr, FormatHelper formatHelper) Executes the toString operation.
String	getAlias() Gets the alias of the expression type.
String	getDescription() Gets a description for the operation.
ExpressionOperation	getOperation(Operation operation) Gets the operation implementation that matches the given operation.
Set	getOperationNames() Gets all registered operation names.
Map	getOperations() Gets all registered operations.
String	getTypeName() Gets the type name of the expression type.
void	removeAllOperations() Removes all operations.
void	removeOperation(String name) Removes an operation.
Object	typeCast(Object value) Casts the given value into the handler-specific type.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.ujac.util.exi.ExpressionType

getType

Field Detail

interpreter

protected ExpressionInterpreter interpreter

The expression interpreter.

operations

protected Map operations

The operation map.

Constructor Detail

BaseType

public BaseType(ExpressionInterpreter interpreter)

Constructs a BaseType instace with specific attributes.

Parameters:

interpreter - The expression interpreter.

Method Detail

execToString

protected String execToString(ExpressionTuple expr,
                              FormatHelper formatHelper)

Executes the toString operation.

Parameters:

expr - The expression, holding the object to get as string.

formatHelper - The format helper to use.

Returns:

The textual representation of the expression value.

getOperation

public ExpressionOperation getOperation(Operation operation)

Description copied from interface: ExpressionType

Gets the operation implementation that matches the given operation.

Specified by:

getOperation in interface ExpressionType

Parameters:

operation - gets the expression operation for the given operation definition.

Returns:

The operation object if a operation for this name is defined else null.

See Also:

ExpressionType.getOperation(org.ujac.util.exi.Operation)

getOperationNames

public Set getOperationNames()

Gets all registered operation names.

Specified by:

getOperationNames in interface ExpressionType

Returns:

The names of the operations, registerd with this type handler.

getOperations

public Map getOperations()

Gets all registered operations.

Specified by:

getOperations in interface ExpressionType

Returns:

The operations, registerd with this type handler.

addOperation

public void addOperation(String name,
                         ExpressionOperation operation)

Adds an operation.

Parameters:

name - The name of the operation.

operation - The operation.

removeOperation

public void removeOperation(String name)

Removes an operation.

Parameters:

name - The name of the operation.

removeAllOperations

public void removeAllOperations()

Removes all operations.

evalTuple

public Object evalTuple(ExpressionTuple expr,
                        ExpressionContext ctx)
                 throws ExpressionException

Evaluates the given expression tuple.

Specified by:

evalTuple in interface ExpressionType

Parameters:

expr - The expression tuple to evaluate.

ctx - The expression context.

Returns:

The result of the tuple evaluation.

Throws:

ExpressionException - If the evaluation failed.

getTypeName

public String getTypeName()

Gets the type name of the expression type.

Specified by:

getTypeName in interface ExpressionType

Returns:

The name of the class the expression type is valid for.

getAlias

public String getAlias()

Gets the alias of the expression type.

Specified by:

getAlias in interface ExpressionType

Returns:

The type alias.

getDescription

public String getDescription()

Gets a description for the operation.

Specified by:

getDescription in interface ExpressionType

Returns:

The item's description.

typeCast

public Object typeCast(Object value)
                throws TypeCastException

Casts the given value into the handler-specific type.

Specified by:

typeCast in interface ExpressionType

Parameters:

value - The value to cast.

Returns:

The transformed value.

Throws:

TypeCastException - In case the type cast failed.