| /******************************************************************************* |
| * 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; |
| } |
| } |
| |
| } |