/*
* Copyright 2013 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.dev.util;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import java.io.Serializable;
/**
* A handle for interacting with a persisted or to be persisted object.
*
* @param <T> the type of object being serialized
*/
public interface PersistenceBackedObject<T> extends Serializable {
/**
* Returns whether the intended persistence location is already populated. For example if
* persisting to a file this would be whether or not the file already exists.
*/
boolean exists();
/**
* Returns the path to the intended persistence location.
*/
String getPath();
/**
* Constructs and returns a new instance of the object stored at the path.
*
* @throws UnableToCompleteException if the backing store does not contain an object of type
* <code>T</code>
*/
T newInstance(TreeLogger logger) throws UnableToCompleteException;
/**
* Serializes the provided object to the intended path. Can only be set once.
*
* @throws UnableToCompleteException if the object could not be serialized
*/
void set(TreeLogger logger, T object) throws IllegalStateException, UnableToCompleteException;
}