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/*******************************************************************************
* Copyright (c) 2007, 2010 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0, which accompanies this distribution
* and is available at http://www.eclipse.org/legal/epl-v10.html.
*
* Contributors:
* Oracle - initial API and implementation
******************************************************************************/
package org.eclipse.jpt.utility.internal;
import java.io.Serializable;
/**
* Used by various "pluggable" classes to transform objects
* into strings.
*/
public interface StringConverter<T> {
/**
* Convert the specified object into a string.
* The semantics of "convert" is determined by the
* contract between the client and the server.
*/
String convertToString(T o);
final class Default<S> implements StringConverter<S>, Serializable {
@SuppressWarnings("rawtypes")
public static final StringConverter INSTANCE = new Default();
@SuppressWarnings("unchecked")
public static <R> StringConverter<R> instance() {
return INSTANCE;
}
// ensure single instance
private Default() {
super();
}
// simply return the object's #toString() result
public String convertToString(S o) {
return (o == null) ? null : o.toString();
}
@Override
public String toString() {
return "StringConverter.Default"; //$NON-NLS-1$
}
private static final long serialVersionUID = 1L;
private Object readResolve() {
// replace this object with the singleton
return INSTANCE;
}
}
final class Disabled<S> implements StringConverter<S>, Serializable {
@SuppressWarnings("rawtypes")
public static final StringConverter INSTANCE = new Disabled();
@SuppressWarnings("unchecked")
public static <R> StringConverter<R> instance() {
return INSTANCE;
}
// ensure single instance
private Disabled() {
super();
}
// throw an exception
public String convertToString(S o) {
throw new UnsupportedOperationException();
}
@Override
public String toString() {
return "StringConverter.Disabled"; //$NON-NLS-1$
}
private static final long serialVersionUID = 1L;
private Object readResolve() {
// replace this object with the singleton
return INSTANCE;
}
}
}
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