org.mmbase.storage.search.implementation
Class BasicStepField

java.lang.Object
  org.mmbase.storage.search.implementation.BasicStepField

All Implemented Interfaces:

Serializable, StepField, SizeMeasurable

Direct Known Subclasses:

BasicAggregatedField

public class BasicStepField
extends Object
implements StepField, SizeMeasurable, Serializable

Basic implementation. The field alias is not set on default.

Since:

MMBase-1.7

Version:

$Id: BasicStepField.java 42075 2010-04-29 11:50:14Z michiel $

Author:

Rob van Maris

See Also:

Serialized Form

Field Summary

protected boolean

modifiable

Constructor Summary

BasicStepField(Step step, Field f)
Constructor.

Method Summary

(package private) static boolean	compareSteps(Step step1, Step step2) Utility method, compares steps by their alias or table name.
(package private) static boolean	equalFieldValues(Object value1, Object value2) Compares two field values for equality.
boolean	equals(Object obj) Compares this stepfield to the specified object.
String	getAlias() Gets the alias for the associated field.
int	getByteSize() Determines the byte-size of this object
int	getByteSize(SizeOf sizeof) Determines the byte-size of this object using the given SizeOf instance.
Field	getField() Gets the associated field.
String	getFieldName() Gets the name of the associated field (without prefix).
static String	getFieldName(StepField field) Returns the field's fieldname, possibly extended with the step's name if known.
Step	getStep() Gets the step associated with this fieldstep.
int	getType() Gets the type of the associated field.
int	hashCode()
BasicStepField	setAlias(String alias) Sets alias property.
void	setUnmodifiable()
(package private) static void	testValue(Object value, StepField field) Tests if a value is acceptable for comparison with a certain field.
String	toString() Returns a string representation of this StepField.

Methods inherited from class java.lang.Object

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

Field Detail

modifiable

protected boolean modifiable

Constructor Detail

BasicStepField

public BasicStepField(Step step,
                      Field f)

Constructor.

Parameters:

step - The associated step.

field - The associated field.

Throws:

IllegalArgumentException - when an invalid argument is supplied.

Method Detail

testValue

static void testValue(Object value,
                      StepField field)

Tests if a value is acceptable for comparison with a certain field.

Parameters:

value - The value to be tested.

field - The non-null field.

Throws:

IllegalArgumentException - when the value is not acceptable for this field.

equalFieldValues

static boolean equalFieldValues(Object value1,
                                Object value2)

Compares two field values for equality. Numerical fields are compared based on their numerical value, as they may be of different type.

Parameters:

value1 - The first value, either a String or a Number

value2 - The second value, either a String or a Number

Returns:

True if both values represent the same string or numerical value.

setUnmodifiable

public void setUnmodifiable()

Specified by:

setUnmodifiable in interface StepField

Since:

MMBase-1.9.2

setAlias

public BasicStepField setAlias(String alias)

Sets alias property.

Parameters:

alias - The alias property.

Returns:

This BasicStepField instance.

Throws:

IllegalArgumentException - when an invalid argument is supplied.

getField

public Field getField()

Gets the associated field.

Returns:

The field.

getFieldName

public final String getFieldName()

Description copied from interface: StepField

Gets the name of the associated field (without prefix).

This corresponds to the fieldname in SQL SELECT-syntax.

Specified by:

getFieldName in interface StepField

getAlias

public String getAlias()

Description copied from interface: StepField

Gets the alias for the associated field.

This corresponds to the field alias in SQL SELECT-syntax.

Specified by:

getAlias in interface StepField

getStep

public Step getStep()

Description copied from interface: StepField

Gets the step associated with this fieldstep.

Specified by:

getStep in interface StepField

getType

public int getType()

Description copied from interface: StepField

Gets the type of the associated field. This is one of the values defined in Field.

Specified by:

getType in interface StepField

equals

public boolean equals(Object obj)

Description copied from interface: StepField

Compares this stepfield to the specified object. The result is true if and only if the argument is a non-null StepField object associated with the same field, using the same alias.

Specified by:

equals in interface StepField

Overrides:

equals in class Object

Parameters:

obj - The object to compare with.

Returns:

true if the objects are equal, false otherwise.

hashCode

public int hashCode()

Specified by:

hashCode in interface StepField

Overrides:

hashCode in class Object

compareSteps

static boolean compareSteps(Step step1,
                            Step step2)

Utility method, compares steps by their alias or table name. Steps are considered equal if their aliases are equal. When their aliases are null, the steps are considered equal if their tablenames are equal as well.

This can be used to verify that both steps refer to the same step in a SearchQuery object. Note that this differs from the equality defined by their equals() method.

Parameters:

step1 - The first step.

step2 - The second step.

Returns:

true when the steps are considered equal, false otherwise.

getFieldName

public static String getFieldName(StepField field)

Returns the field's fieldname, possibly extended with the step's name if known. May return null or partial fieldnames if not all data is available (for use in debugging).

Parameters:

field - the fieldname whose name to return

toString

public String toString()

Description copied from interface: StepField

Returns a string representation of this StepField. The string representation has the form "StepField(step:<step>, fieldname:<fieldname>, alias:<alias>)" where

• <step> is the step alias returned by getStep().getAlias() or, when the step alias is null, the step tablename returned by getStep().getTableName().
• <fieldname> is the fieldname returned by getFieldName()
• <alias> is the alias returned by getAlias()

Specified by:

toString in interface StepField

Overrides:

toString in class Object

Returns:

A string representation of this StepField.

getByteSize

public int getByteSize()

Description copied from interface: SizeMeasurable

Determines the byte-size of this object

Specified by:

getByteSize in interface SizeMeasurable

getByteSize

public int getByteSize(SizeOf sizeof)

Description copied from interface: SizeMeasurable

Determines the byte-size of this object using the given SizeOf instance. A SizeOf instance stores a Set already counted objects. So this method is typically called by SizeOf itself (recursion).

Specified by:

getByteSize in interface SizeMeasurable