/*
* Copyright 2002-2013 the original author or authors
*
* 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.github.springtestdbunit.dataset;
import org.dbunit.dataset.IDataSet;
import org.springframework.core.io.ClassRelativeResourceLoader;
import org.springframework.core.io.Resource;
import org.springframework.core.io.ResourceLoader;
/**
* Abstract data set loader, which provides a basis for concrete implementations of the {@link DataSetLoader} strategy.
* Provides a <em>Template Method</em> based approach for {@link #loadDataSet(Class, String) loading} data using a
* Spring {@link #getResourceLoader resource loader}.
*
* @author Phillip Webb
*
* @see #getResourceLoader
* @see #getResourceLocations
* @see #createDataSet(Resource)
*/
public abstract class AbstractDataSetLoader implements DataSetLoader {
/**
* Loads a {@link IDataSet dataset} from {@link Resource}s obtained from the specified <tt>location</tt>. Each
* <tt>location</tt> can be mapped to a number of potential {@link #getResourceLocations resources}, the first
* resource that {@link Resource#exists() exists} will be used. {@link Resource}s are loaded using the
* {@link ResourceLoader} returned from {@link #getResourceLoader}.
* <p>
* If no resource can be found then <tt>null</tt> will be returned.
*
* @see #createDataSet(Resource)
* @see com.github.springtestdbunit.dataset.DataSetLoader#loadDataSet(Class, String) java.lang.String)
*/
public IDataSet loadDataSet(Class<?> testClass, String location) throws Exception {
ResourceLoader resourceLoader = getResourceLoader(testClass);
String[] resourceLocations = getResourceLocations(testClass, location);
for (String resourceLocation : resourceLocations) {
Resource resource = resourceLoader.getResource(resourceLocation);
if (resource.exists()) {
return createDataSet(resource);
}
}
return null;
}
/**
* Gets the {@link ResourceLoader} that will be used to load the dataset {@link Resource}s.
* @param testClass The class under test
* @return a resource loader
*/
protected ResourceLoader getResourceLoader(Class<?> testClass) {
return new ClassRelativeResourceLoader(testClass);
}
/**
* Get the resource locations that should be considered when attempting to load a dataset from the specified
* location.
* @param testClass The class under test
* @param location The source location
* @return an array of potential resource locations
*/
protected String[] getResourceLocations(Class<?> testClass, String location) {
return new String[] { location };
}
/**
* Factory method used to create the {@link IDataSet dataset}
* @param resource an existing resource that contains the dataset data
* @return a dataset
* @throws Exception if the dataset could not be loaded
*/
protected abstract IDataSet createDataSet(Resource resource) throws Exception;
}