org.objectweb.jonathan.apis.kernel
Interface Context

All Known Subinterfaces:

Configuration

All Known Implementing Classes:

JContextFactory.JContext

public interface Context

A context represents a set of typed objects, each identified by a name.

Inner Class Summary

static class

Context.NO_VALUE

Field Summary

static Object

NO_VALUE The NO_VALUE object is returned by getValue if no value corresponds to the provided name.

Method Summary

void	acquire() Acquires the target context.
Element	addElement(Element element) Adds an element to the target context.
Element	addElement(Name name, Class type, int value) Adds an element to the target context.
Element	addElement(Name name, Class type, Object value) Adds an element in the target context.
Element	addElement(String name, Class type, int value, char separator) Adds an element to the target context.
Element	addElement(String name, Class type, Object value, char separator) Adds an element to the target context.
Element	getElement(Name name) Returns the element in the target context identified by name, null if no element is registered under name name.
Element	getElement(String name, char separator) Returns the element in the target context identified by name, null if no element is registered under name name.
Enumeration	getElements() Returns an enumeration of the elements found in the target context.
int	getIntValue(Name name) Returns the value of the element registered in the target context under the name name.
int	getIntValue(String name, char separator) Returns the value of the element registered in the target context under the name name.
Context	getScope() Returns the scope of the target context;
Object	getValue(Name name) Returns the value of the element registered in the target context under the name name.
Object	getValue(String name, char separator) Returns the value of the element registered in the target context under the name name.
void	release() Releases the target context, releasing all the resources it uses, if no one still uses it.
void	reset() Resets the target context, removing all its current elements.
Context	setScope(Context scope) Sets the scope of the target context;

Field Detail

NO_VALUE

public static final Object NO_VALUE

The NO_VALUE object is returned by getValue if no value corresponds to the provided name.

Method Detail

addElement

public Element addElement(Name name,
                          Class type,
                          Object value)
                   throws JonathanException

Adds an element in the target context.

Parameters:

name - the name of the object to be added;

type - the type of the object to be added;

value - the object to be added.

Returns:

the previous element, if any; null otherwise.

Throws:

JonathanException - if something goes wrong (usually, a type exception).

addElement

public Element addElement(Name name,
                          Class type,
                          int value)
                   throws JonathanException

Adds an element to the target context. In this case, the value's type must be promotable to an integer. Class is one of int.class, short.class, char.class, or byte.class.

Parameters:

name - the name of the element to be added;

value - the integer value of the element to be added;

Returns:

the previous element, if any, null otherwise.

Throws:

JonathanException - if something goes wrong (usually, a type exception).

addElement

public Element addElement(Element element)
                   throws JonathanException

Adds an element to the target context.

Parameters:

element - the element to be added.

Returns:

the previous element, if any, null otherwise.

Throws:

JonathanException - if something goes wrong (usually, a type exception).

addElement

public Element addElement(String name,
                          Class type,
                          Object value,
                          char separator)
                   throws JonathanException

Adds an element to the target context. This method is equivalent to addElement(Name,Class,Object), except that the name to use is specified by a string and a separator separating the different elements of the name. If separator == 0, the name corresponds to an object local to the target context. If the name begins with the separator, the name is an absolute name (this only makes sense if the context has a tree structure); otherwise, the name is relative to the target context.

Parameters:

name - a string representing the name of the seeked element;

type - the type of the object to be added;

value - the object to be added;

separator - the separator character used to parse name;

Returns:

the previous element, if any; null otherwise.

Throws:

JonathanException - if something goes wrong (usually, a type exception).

addElement

public Element addElement(String name,
                          Class type,
                          int value,
                          char separator)
                   throws JonathanException

Adds an element to the target context. This method is equivalent to addElement(Name,Class,int), except that the name to use is specified by a string and a separator separating the different elements of the name. If separator == 0, the name corresponds to an object local to the target context. If the name begins with the separator, the name is an absolute name (this only makes sense if the context has a tree structure); otherwise, the name is relative to the target context.

Parameters:

name - a string representing the name of the seeked element;

value - the integer value of the element to be added;

separator - the separator character used to parse name;

Returns:

the previous element, if any; null otherwise.

Throws:

JonathanException - if something goes wrong (usually, a type exception).

getElement

public Element getElement(Name name)

Returns the element in the target context identified by name, null if no element is registered under name name.

Parameters:

name - the name of the element to be retrieved;

Returns:

the corresponding element, if any; null otherwise.

getElement

public Element getElement(String name,
                          char separator)

Returns the element in the target context identified by name, null if no element is registered under name name. This method is equivalent to getElement(Name), except that the name to use is specified by a string and a separator separating the different elements of the name. If separator == 0, the name corresponds to an object local to the target context. If the name begins with the separator, the name is an absolute name (this only makes sense if the context has a tree structure); otherwise, the name is relative to the target context.

Parameters:

name - a string representing the name of the seeked element;

separator - the separator character used to parse name;

Returns:

the corresponding element, if any; null otherwise.

getValue

public Object getValue(Name name)

Returns the value of the element registered in the target context under the name name. A call to getValue(name) is equivalent to getElement(name).getValue() if the provided name actually corresponds to an element. If it is not the case, NO_VALUE is returned.

Parameters:

name - the name of the element whose value is seeked;

Returns:

the corresponding value, or NO_VALUE.

getValue

public Object getValue(String name,
                       char separator)

Returns the value of the element registered in the target context under the name name. This method is equivalent to getValue(Name), except that the name to use is specified by a string and a separator separating the different elements of the name. If separator == 0, the name corresponds to an object local to the target context. If the name begins with the separator, the name is an absolute name (this only makes sense if the context has a tree structure); otherwise, the name is relative to the target context.

Parameters:

name - the name of the element whose value is seeked;

separator - the separator character used to parse name;

Returns:

the corresponding value, or NO_VALUE.

getIntValue

public int getIntValue(Name name)

Returns the value of the element registered in the target context under the name name.

A call to getIntValue(name) is equivalent to getElement(name).getIntValue() if the provided name actually corresponds to an element. If it is not the case, Integer.MAX_VALUE is returned.

Parameters:

name - the name of the element whose value is seeked;

Returns:

the corresponding value, or Integer.MAX_VALUE

getIntValue

public int getIntValue(String name,
                       char separator)

Returns the value of the element registered in the target context under the name name. This method is equivalent to getIntValue(Name), except that the name to use is specified by a string and a separator separating the different elements of the name. If separator == 0, the name corresponds to an object local to the target context. If the name begins with the separator, the name is an absolute name (this only makes sense if the context has a tree structure); otherwise, the name is relative to the target context.

Parameters:

name - the name of the element whose value is seeked;

separator - the separator character used to parse name;

Returns:

the corresponding value, or Integer.MAX_VALUE

getElements

public Enumeration getElements()

Returns an enumeration of the elements found in the target context.

Returns:

an enumeration of the elements found in the target context.

release

public void release()

Releases the target context, releasing all the resources it uses, if no one still uses it. The context should no longer be used once it has been released.

acquire

public void acquire()

Acquires the target context.

reset

public void reset()

Resets the target context, removing all its current elements.

setScope

public Context setScope(Context scope)

Sets the scope of the target context;

Parameters:

scope - the new scope of the target context;

Returns:

the previous scope of the target context;

getScope

public Context getScope()

Returns the scope of the target context;

Returns:

the scope of the target context;