Difference between revisions of "OSGi Concepts Services"

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}
 
}
  
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</source>
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 +
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An implementation of this interface could be:
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<source lang="java">
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package cs.ecl.osgi.simple.declarativeservice.say.internals;
 +
 +
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import java.util.Date;
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 +
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import cs.ecl.osgi.simple.declarativeservice.say.Sayable;
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public class TodaySay implements Sayable {
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 +
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public String say() {
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return " Declarative Service: Today is " + new Date();
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}
 +
}
 
</source>
 
</source>

Revision as of 16:33, 21 January 2011

OSGi Services

A bundles can register and use services in OSGi. OSGi provides therefore a central registry for this purpose. A service is defined by a Java interface (POJI - Plain Old Java Interface) [1].
Access to the service registry is performed via the class BundleContext. OSGi injects the BundleContext into each bundle during the startup of the bundle. A bundle can also register itself to the BundleContext ServiceEvents which are for example triggered if a new service is installed or de-installed.

For example, let us suppose that one wants to define a service that is capable to define the day and time. For the purpose one defines an interface:

package cs.ecl.osgi.simple.declarativeservice.say;

public interface Sayable {
	String say();
}


An implementation of this interface could be:

package cs.ecl.osgi.simple.declarativeservice.say.internals;


import java.util.Date;


import cs.ecl.osgi.simple.declarativeservice.say.Sayable;


public class TodaySay implements Sayable {


	public String say() {
		return " Declarative Service: Today is " + new Date();
	}
}