org.astrogrid.samp
Class SampMap

java.lang.Object
  java.util.AbstractMap
      org.astrogrid.samp.SampMap

All Implemented Interfaces:

Map

Direct Known Subclasses:

ErrInfo, LockInfo, Message, Metadata, RegInfo, Response, Subscriptions

public abstract class SampMap
extends AbstractMap

Abstract superclass for objects represented within the SAMP package as key-value maps. There are several of these, represented by subclasses of SampMap, for instance Message, Metadata etc. A SampMap is-a Map, but has some additional useful features:

• its entries are ordered in a convenient fashion
• it contains some general-purpose utility methods appropriate to SAMP maps
• particular subclasses contain specific constants and utility methods, e.g. well-known keys and accessor methods for them
• concrete subclasses provide a static asClass method to convert from a normal Map to the class in question

In general any time a map-encoded object is required by a method in the toolkit, any Map can be used. When the toolkit provides a map-encoded object however (as return value or callback method parameter), an object of the more specific SampMap type is used. This allows maximum convenience for the application programmer, but means that you don't have to use these additional features if you don't want to, you can treat everything as a plain old Map.

Since:

14 Jul 2008

Author:

Mark Taylor

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry

Field Summary

static Map

EMPTY

Constructor Summary

protected

SampMap(String[] knownKeys) Constructor.

Method Summary

void	check() Checks that this object is ready for use with the SAMP toolkit.
void	checkHasKeys(String[] keys) Checks that this map contains at least the given set of keys.
Set	entrySet()
List	getList(String key) Returns the value for a given key in this map, cast to List.
Map	getMap(String key) returns the value for a given key in this map, cast to Map.
String	getString(String key) Returns the value for a given key in this map, cast to String.
URL	getUrl(String key) Returns the value for a given key in this map as a URL.
Object	put(Object key, Object value)

Methods inherited from class java.util.AbstractMap

clear, clone, containsKey, containsValue, equals, get, hashCode, isEmpty, keySet, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY

public static final Map EMPTY

Constructor Detail

SampMap

protected SampMap(String[] knownKeys)

Constructor. The given array of well-known keys will appear first in the list of entries when this map is iterated over. Other entries will appear in alphabetical order.

Parameters:

knownKeys - array of well-known keys for this class

Method Detail

put

public Object put(Object key,
                  Object value)

Specified by:

put in interface Map

Overrides:

put in class AbstractMap

entrySet

public Set entrySet()

Specified by:

entrySet in interface Map

Specified by:

entrySet in class AbstractMap

check

public void check()

Checks that this object is ready for use with the SAMP toolkit. As well as calling SampUtils.checkMap(java.util.Map) (ensuring that all keys are Strings, and all values Strings, Lists or Maps), subclass-specific invariants may be checked. In the case that there's something wrong, an informative DataException will be thrown.

Throws:

DataException - if this object's current state is not suitable for SAMP use

checkHasKeys

public void checkHasKeys(String[] keys)

Checks that this map contains at least the given set of keys. If any is absent, an informative DataException will be thrown. Normally called by check().

Parameters:

keys - array of required keys for this map

Throws:

DataException - if this object does not contain entries for all elements of the array keys

getString

public String getString(String key)

Returns the value for a given key in this map, cast to String.

Returns:

string value for key

getMap

public Map getMap(String key)

returns the value for a given key in this map, cast to Map.

Returns:

map value for key

getList

public List getList(String key)

Returns the value for a given key in this map, cast to List.

Returns:

list value for key

getUrl

public URL getUrl(String key)

Returns the value for a given key in this map as a URL.

Returns:

URL value for key