com.tomgibara.pronto.config.source
Class SystemConfigSource

java.lang.Object
  com.tomgibara.pronto.config.source.SystemConfigSource

All Implemented Interfaces:

ConfigSource

public class SystemConfigSource
extends java.lang.Object
implements ConfigSource

Enacapsulates the system properties as a ConfigSource. Note that calling either method on this class is a moderately expensive operation. For this reason, it is recommended that instances of this class are wrapped in a CachingConfigSource if used in conjunction with ConfigPolicy objects featuring very small minimum read periods. This class is not safe for concurrent use. Wrap instances in a SynchronousConfigSource if thread safety is required.

Author:

Tom Gibara

Constructor Summary

SystemConfigSource()

Method Summary

java.util.Map<java.lang.String,java.lang.String>	getProperties() A map of the configuration properties supplied by this source.
long	lastModified() Returns the time at which the properties were last known to have changed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SystemConfigSource

public SystemConfigSource()

Method Detail

lastModified

public long lastModified()
                  throws java.lang.RuntimeException

Description copied from interface: ConfigSource

Returns the time at which the properties were last known to have changed. This method must be implemented and MAY NOT return rogue values if the time is unknown. The correct behaviour in such circumstances is to return the current system time. If calculation of the time fails, the implementation is free to throw a runtime exception of its choosing.

Specified by:

lastModified in interface ConfigSource

Returns:

time at which the system properties were known to have last changed.

Throws:

java.lang.RuntimeException - if the system properties cannot be accessed

getProperties

public java.util.Map<java.lang.String,java.lang.String> getProperties()
                                                               throws java.lang.RuntimeException

Description copied from interface: ConfigSource

A map of the configuration properties supplied by this source. The map returned by this method will not be modified by the config. The implementation is free to throw an unchecked exception of its choice if the properties cannot be supplied.

Specified by:

getProperties in interface ConfigSource

Returns:

a snapshot of the present system properties

Throws:

java.lang.RuntimeException - if the system properties cannot be accessed