Return the value stored in the preference store for the given key.
If the key is not defined then return the specified default value.
Use the canonical scope lookup order for finding the preference value.
The semantics of this method are to calculate the appropriate
Preferences nodes in the preference hierarchy to use
and then call the
#get(String,String,Preferences[])method. The order of the nodes is calculated by consulting the default
scope lookup order as set by
#setDefaultLookupOrder(String,String,String[]).
The specified key may either refer to a simple key or be the concatenation of the
path of a child node and key. If the key contains a slash ("/") character, then a
double-slash must be used to denote the end of they child path and the beginning
of the key. Otherwise it is assumed that the key is the last segment of the path.
The following are some examples of keys and their meanings:
- "a" - look for a value for the property "a"
- "//a" - look for a value for the property "a"
- "///a" - look for a value for the property "/a"
- "//a//b" - look for a value for the property "a//b"
- "a/b/c" - look in the child node "a/b" for property "c"
- "/a/b/c" - look in the child node "a/b" for property "c"
- "/a/b//c" - look in the child node "a/b" for the property "c"
- "a/b//c/d" - look in the child node "a/b" for the property "c/d"
- "/a/b//c/d" - look in the child node "a/b" for the property "c/d"
- "/a/b//c//d" - look in the child node "a/b" for the property "c//d"
The scope look-up order is determined by the preference service default
lookup order, not by the order of the scope contexts that are being passed in.
The context objects are only consulted to help determine which nodes to
look in, not the order of the nodes.
Callers may specify an array of scope context objects to aid in the
determination of the correct nodes. For each entry in the lookup
order, the array of contexts is consulted and if one matching the
scope exists, then it is used to calculate the node. Otherwise a
default calculation algorithm is used.
An example of a qualifier for an Eclipse 2.1 preference is the
plug-in identifier. (e.g. "org.eclipse.core.resources" for "description.autobuild")