java.lang.Object
java.lang.Throwable
java.lang.Exception
java.lang.InstantiationException
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- Serializable
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Class.newInstance()
public InstantiationException()
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[1100]Use reflection to instantiate singletons
By Anonymous on 2004/11/05 17:41:37 Rate
//Use reflection to instantiate singletons
import java.util.HashMap;
import org.apache.log4j.Logger;
public class Singleton {
private static HashMap map = new HashMap ( ) ;
private static Logger logger = Logger.getRootLogger ( ) ;
protected Singleton ( ) {
// Exists only to thwart instantiation
}
public static synchronized Singleton getInstance ( String classname ) {
Singleton singleton = ( Singleton ) map.get ( classname ) ;
if ( singleton != null ) {
logger.info ( "got singleton from map: " + singleton ) ;
return singleton;
}
try {
singleton = ( Singleton ) Class.forName ( classname ) .newInstance ( ) ;
}
catch ( ClassNotFoundException cnf ) {
logger.fatal ( "Couldn't find class " + classname ) ;
}
catch ( InstantiationException ie ) {
logger.fatal ( "Couldn't instantiate an object of type " + classname ) ;
}
catch ( IllegalAccessException ia ) {
logger.fatal ( "Couldn't access class " + classname ) ;
}
map.put ( classname, singleton ) ;
logger.info ( "created singleton: " + singleton ) ;
return singleton;
}
}
public InstantiationException(String s)
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