org.apache.tamaya.resolver.internal

Class SystemPropertyResolver

java.lang.Object

org.apache.tamaya.resolver.internal.SystemPropertyResolver

All Implemented Interfaces:

ExpressionResolver

@Priority(value=100)
public final class SystemPropertyResolver
extends Object
implements ExpressionResolver

Property resolver implementation that interprets the resolver expression as system property name. It can be explicitly addressed by prefixing sys:, e.g. ${sys:mySystemProperty}.

Constructor Summary

Constructors

Constructor and Description
SystemPropertyResolver()

Method Summary

Methods

Modifier and Type	Method and Description
String	evaluate(String expression) Evaluates the given expression.
String	getResolverPrefix() Get the unique resolver prefix.

Methods inherited from class java.lang.Object

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

Constructor Detail

SystemPropertyResolver

public SystemPropertyResolver()

Method Detail

getResolverPrefix

public String getResolverPrefix()

Description copied from interface: ExpressionResolver

Get the unique resolver prefix. This allows to address a resolver explicitly, in case of conflicts. By default all registered resolvers are called in order as defined by the Priority annotation.

Specified by:

getResolverPrefix in interface ExpressionResolver

Returns:

the prefix that identifies this resolver instance, e.g. 'config:'. The ':' hereby is not required as a separator, but it is recommended to use it, because it fits well, with the other existing resolvers and is easy to read.

evaluate

public String evaluate(String expression)

Description copied from interface: ExpressionResolver

Evaluates the given expression.

Specified by:

evaluate in interface ExpressionResolver

Parameters:

expression - the expression to be evaluated, not null. If a resolver was addressed explicitly, the prefix is removed prior to calling this method.

Returns:

the evaluated expression, or null, if the evaluator is not able to resolve the expression.