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public interface Location
A Location represents a URL which may have a default value, may be read only, may or may not have a current value and may be cascaded on to a parent location.
This interface is not intended to be implemented by clients.
Field Summary | |
---|---|
static java.lang.String |
CONFIGURATION_FILTER
Constant which defines the filter string for acquiring the service which specifies the configuration location. |
static java.lang.String |
ECLIPSE_HOME_FILTER
Constant which defines the filter string for acquiring the service which specifies the eclipse home location. |
static java.lang.String |
INSTALL_FILTER
Constant which defines the filter string for acquiring the service which specifies the install location. |
static java.lang.String |
INSTANCE_FILTER
Constant which defines the filter string for acquiring the service which specifies the instance location. |
static java.lang.String |
USER_FILTER
Constant which defines the filter string for acquiring the service which specifies the user location. |
Method Summary | |
---|---|
boolean |
allowsDefault()
Returns true if this location allows a default value to be assigned
and false otherwise. |
Location |
createLocation(Location parent,
java.net.URL defaultValue,
boolean readonly)
Constructs a new location. |
java.net.URL |
getDefault()
Returns the default value of this location if any. |
Location |
getParentLocation()
Returns the parent of this location or null if none is available. |
java.net.URL |
getURL()
Returns the actual URL of this location. |
boolean |
isLocked()
Returns true if this location is locked and false
otherwise. |
boolean |
isReadOnly()
Returns true if this location represents a read only location and
false otherwise. |
boolean |
isSet()
Returns true if this location has a value and false
otherwise. |
boolean |
lock()
Attempts to lock this location with a canonical locking mechanism and return true if the lock could be acquired. |
void |
release()
Releases the lock on this location. |
boolean |
set(java.net.URL value,
boolean lock)
Sets and optionally locks the location's value to the given URL . |
boolean |
setURL(java.net.URL value,
boolean lock)
Deprecated. use set(URL, boolean) instead. |
Field Detail |
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static final java.lang.String INSTANCE_FILTER
static final java.lang.String INSTALL_FILTER
static final java.lang.String CONFIGURATION_FILTER
static final java.lang.String USER_FILTER
static final java.lang.String ECLIPSE_HOME_FILTER
Method Detail |
---|
boolean allowsDefault()
true
if this location allows a default value to be assigned
and false
otherwise.
java.net.URL getDefault()
null
is returned. Note that even locations which allow defaults may still
return null
.
null
Location getParentLocation()
null
if none is available.
null
java.net.URL getURL()
URL
of this location. If the location's value has been set,
that value is returned. If the value is not set and the location allows defaults,
the value is set to the default and returned. In all other cases null
is returned.
null
if noneboolean isSet()
true
if this location has a value and false
otherwise.
boolean isReadOnly()
true
if this location represents a read only location and
false
otherwise. The read only character
of a location is not in enforced in any way but rather expresses the intention of the
location's creator.
boolean setURL(java.net.URL value, boolean lock) throws java.lang.IllegalStateException
set(URL, boolean)
instead.
URL
. If the location
already has a value an exception is thrown. If locking is requested and fails, false
is returned and the URL
of this location is not set.
value
- the value of this locationlock
- whether or not to lock this location
java.lang.IllegalStateException
- if the location's value is already setboolean set(java.net.URL value, boolean lock) throws java.lang.IllegalStateException, java.io.IOException
URL
. If the location
already has a value an exception is thrown. If locking is requested and fails, false
is returned and the URL
of this location is not set.
value
- the value of this locationlock
- whether or not to lock this location
java.lang.IllegalStateException
- if the location's value is already set
java.io.IOException
- if there was an unexpected problem while acquiring the lockboolean lock() throws java.io.IOException
true
if the lock could be acquired. Not all locations can be
locked.
Locking a location is advisory only. That is, it does not prevent other applications from modifying the same location
java.io.IOException
- if there was an unexpected problem while acquiring the lockvoid release()
boolean isLocked() throws java.io.IOException
true
if this location is locked and false
otherwise.
java.io.IOException
- if there was an unexpected problem reading the lockLocation createLocation(Location parent, java.net.URL defaultValue, boolean readonly)
parent
- the parent location. A null
value is allowed.defaultValue
- the default value of the location. A null
value is allowed.readonly
- true if the location is read-only.
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