org.mmbase.util.functions
Class Parameters

java.lang.Object
  java.util.AbstractCollection
      java.util.AbstractList
          org.mmbase.util.functions.Parameters

All Implemented Interfaces:

Collection, List, Serializable

Direct Known Subclasses:

AutodefiningParameters

public class Parameters

extends AbstractList

implements Serializable

This class implemements the Parameters interface. It provides a convenient way to create a List that allows the use of 'named parameters'. This List is therefore backed by a HashMap, but it behaves as a list. So if you set a parameter with a certain name, it always appears in the same location of the List. This List is modifiable but not resizeable. It is always the size of the definition array.

Since:

MMBase-1.7

Version:

$Id: Parameters.java,v 1.23 2006/03/23 19:55:06 michiel Exp $

Author:

Michiel Meeuwissen

See Also:

Parameter, Parameters(Parameter[]), Serialized Form

Field Summary

protected boolean	autoCasting If true, values are automatically cast to the right type (if possible) when set.
protected Map	backing The contents of this List are stored in this HashMap.
protected Parameter[]	definition This array maps integers (position in array) to map keys, making it possible to implement List.
static Parameters	VOID No need to bother for the functions with no parameters.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

	Parameters(Parameter[] def) Constructor, taking an Parameter[] array argument.
	Parameters(Parameter[] def, Collection values) If you happen to have a List of parameters, then you can wrap it into an Parameters with this constructor.
protected	Parameters(Parameters params, int from, int to) Used for nicer implemenation of subList (which we want to also be instanceof Parameters).

Method Summary

void	checkRequiredParameters() Throws an IllegalArgumentException if one of the required parameters was not entered.
boolean	containsParameter(Parameter parameter) Checks wether a certain parameter is available, using the Parameter as a qualifier.
boolean	containsParameter(String parameterName) Checks wether a certain parameter is available, using the parameter name as a qualifier.
Object	get(int i)
Object	get(Parameter parameter) Gets the value of a parameter.
Object	get(String parameterName) Gets the value of a parameter.
Parameter[]	getDefinition()
String	getString(Parameter parameter) Gets the value of a parameter, cast to a String.
String	getString(String parameterName) Gets the value of a parameter, cast to a String.
int	indexOfParameter(Parameter parameter) Returns the position of a parameter in the parameters list, using the Parameter as a qualifier.
int	indexOfParameter(String parameterName) Returns the position of a parameter in the parameters list, using the parameter name as a qualifier.
boolean	isAutoCasting() Whether this Parameters object is 'automaticly casting'.
Object	set(int i, Object value)
Parameters	set(Parameter parameter, Object value) Sets the value of a parameter.
Parameters	set(String parameterName, Object value) Sets the value of a parameter.
Parameters	setAll(Collection values) Copies all values of a collection to the corresponding values of this Parameters Object.
Parameters	setAll(Map map) Copies all values of a map to the corresponding values of this Parameters Object.
void	setAutoCasting(boolean autocast) Sets the 'auto casting' property (which on default is false)
Parameters	setIfDefined(Parameter parameter, Object value) Sets the value of an argument, if the argument is defined, otherwise do nothing.
Parameters	setIfDefined(String parameterName, Object value) Sets the value of an argument, if the argument is defined, otherwise do nothing.
int	size()
List	subList(int fromIndex, int toIndex)
Class[]	toClassArray()
Map	toMap() Gives the arguments back as a (unmodifiable) map.
String	toString()

Methods inherited from class java.util.AbstractList

add, add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.List

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray

Field Detail

VOID

public static final Parameters VOID

No need to bother for the functions with no parameters. This is a constant you could supply.

backing

protected Map backing

The contents of this List are stored in this HashMap.

definition

protected Parameter[] definition

This array maps integers (position in array) to map keys, making it possible to implement List.

autoCasting

protected boolean autoCasting

If true, values are automatically cast to the right type (if possible) when set.

Constructor Detail

Parameters

public Parameters(Parameter[] def)

Constructor, taking an Parameter[] array argument. The Parameter may also be Parameter.Wrapper (to implement overriding of functions). The idea is that these array arguments are defined as constants in the classes which define a function with variable arguments.
The Parameter[] array could e.g. be somewhere defined as a constant, like this:

   
     public final static Parameter[] MYFUNCTION_PARAMETERS = {
         new Parameter("type", Integer.class),
         new Parameter("text", String.class),
         Parameter.CLOUD,                                 // a predefined parameter
         new Parameter.Wrapper(OTHERFUNCTION_PARAMETERS)  // a way to include another definition in this one
     };
   
 

Parameters

public Parameters(Parameter[] def,
                  Collection values)

If you happen to have a List of parameters, then you can wrap it into an Parameters with this constructor.

Parameters:

values - Collection with values. This Collection should have a predictable iteration order.

Throws:

NullPointerException - if definition is null

See Also:

Parameters(Parameter[])

Parameters

protected Parameters(Parameters params,
                     int from,
                     int to)

Used for nicer implemenation of subList (which we want to also be instanceof Parameters).

Method Detail

toString

public String toString()

toClassArray

public Class[] toClassArray()

setAutoCasting

public void setAutoCasting(boolean autocast)

Sets the 'auto casting' property (which on default is false)

Parameters:

autocast - the new value for autocast

See Also:

isAutoCasting()

getDefinition

public Parameter[] getDefinition()

isAutoCasting

public boolean isAutoCasting()

Whether this Parameters object is 'automaticly casting'. If it is, that means that you can set e.g. an Integer by a String.

Returns:

true if autocasting is on

size

public int size()

Specified by:

size in interface List

get

public Object get(int i)

Specified by:

get in interface List

set

public Object set(int i,
                  Object value)

Specified by:

set in interface List

checkRequiredParameters

public void checkRequiredParameters()

Throws an IllegalArgumentException if one of the required parameters was not entered.

indexOfParameter

public int indexOfParameter(Parameter parameter)

Returns the position of a parameter in the parameters list, using the Parameter as a qualifier. you can tehn acecss that paramter with get(int).

Parameters:

parameter - the parameter

Returns:

the index of the parameter, or -1 if it doesn't exist

indexOfParameter

public int indexOfParameter(String parameterName)

Returns the position of a parameter in the parameters list, using the parameter name as a qualifier. you can then acecss that paramter with get(int).

Parameters:

parameterName - the name of the parameter

Returns:

the index of the parameter, or -1 if it doesn't exist

containsParameter

public boolean containsParameter(Parameter parameter)

Checks wether a certain parameter is available, using the Parameter as a qualifier.

Parameters:

parameter - the parameter

Returns:

true if a parameter exists.

containsParameter

public boolean containsParameter(String parameterName)

Checks wether a certain parameter is available, using the parameter name as a qualifier.

Parameters:

parameterName - the name of the parameter

Returns:

true if a parameter exists.

set

public Parameters set(Parameter parameter,
                      Object value)

Sets the value of a parameter.

Parameters:

parameter - the Parameter describing the parameter to set

value - the object value to set

Throws:

IllegalArgumentException - if either the argument name is unknown to this Parameters, or the value is of the wrong type.

set

public Parameters set(String parameterName,
                      Object value)

Sets the value of a parameter.

Parameters:

parameterName - the name of the parameter to set

value - the object value to set

Throws:

IllegalArgumentException - if either the argument name is unknown to this Parameters, or the value is of the wrong type.

setAll

public Parameters setAll(Map map)

Copies all values of a map to the corresponding values of this Parameters Object.

setAll

public Parameters setAll(Collection values)

Copies all values of a collection to the corresponding values of this Parameters Object.

subList

public List subList(int fromIndex,
                    int toIndex)

Specified by:

subList in interface List

setIfDefined

public Parameters setIfDefined(Parameter parameter,
                               Object value)

Sets the value of an argument, if the argument is defined, otherwise do nothing.

Parameters:

parameter - the parameter to set

value - the object value to set

setIfDefined

public Parameters setIfDefined(String parameterName,
                               Object value)

Sets the value of an argument, if the argument is defined, otherwise do nothing.

Parameters:

parameterName - the name of the parameter to set

value - the object value to set

get

public Object get(Parameter parameter)

Gets the value of a parameter.

Parameters:

parameter - the parameter to get

Returns:

value the parameter value

get

public Object get(String parameterName)

Gets the value of a parameter.

Parameters:

parameterName - the name of the parameter to get

Returns:

value the parameter value

getString

public String getString(Parameter parameter)

Gets the value of a parameter, cast to a String.

Parameters:

parameter - the parameter to get

Returns:

value the parameter value as a STring

getString

public String getString(String parameterName)

Gets the value of a parameter, cast to a String.

Parameters:

parameterName - the name of the parameter to get

Returns:

value the parameter value as a STring

toMap

public Map toMap()

Gives the arguments back as a (unmodifiable) map.