/*
* Copyright 2002-2008 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 org.springframework.test.context.support;
import org.springframework.context.ApplicationContext;
import org.springframework.core.io.support.ResourcePatternUtils;
import org.springframework.test.context.ContextLoader;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.ObjectUtils;
import org.springframework.util.ResourceUtils;
import org.springframework.util.StringUtils;
/**
* Abstract application context loader, which provides a basis for all concrete
* implementations of the {@link ContextLoader} strategy. Provides a
* <em>Template Method</em> based approach for
* {@link #processLocations(Class,String...) processing} locations.
*
* @author Sam Brannen
* @author Juergen Hoeller
* @since 2.5
* @see #generateDefaultLocations
* @see #modifyLocations
*/
public abstract class AbstractContextLoader implements ContextLoader {
/**
* If the supplied <code>locations</code> are <code>null</code> or
* <em>empty</em> and {@link #isGenerateDefaultLocations()} is
* <code>true</code>, default locations will be
* {@link #generateDefaultLocations(Class) generated} for the specified
* {@link Class class} and the configured
* {@link #getResourceSuffix() resource suffix}; otherwise, the supplied
* <code>locations</code> will be
* {@link #modifyLocations(Class,String...) modified} if necessary and
* returned.
* @param clazz the class with which the locations are associated: to be
* used when generating default locations
* @param locations the unmodified locations to use for loading the
* application context (can be <code>null</code> or empty)
* @return an array of application context resource locations
* @see #generateDefaultLocations
* @see #modifyLocations
* @see org.springframework.test.context.ContextLoader#processLocations
*/
public final String[] processLocations(Class<?> clazz, String... locations) {
return (ObjectUtils.isEmpty(locations) && isGenerateDefaultLocations()) ?
generateDefaultLocations(clazz) : modifyLocations(clazz, locations);
}
/**
* Generates the default classpath resource locations array based on the
* supplied class.
* <p>For example, if the supplied class is <code>com.example.MyTest</code>,
* the generated locations will contain a single string with a value of
* "classpath:/com/example/MyTest<code><suffix></code>",
* where <code><suffix></code> is the value of the
* {@link #getResourceSuffix() resource suffix} string.
* <p>Subclasses can override this method to implement a different
* <em>default location generation</em> strategy.
* @param clazz the class for which the default locations are to be generated
* @return an array of default application context resource locations
* @see #getResourceSuffix()
*/
protected String[] generateDefaultLocations(Class<?> clazz) {
Assert.notNull(clazz, "Class must not be null");
String suffix = getResourceSuffix();
Assert.hasText(suffix, "Resource suffix must not be empty");
return new String[] { ResourceUtils.CLASSPATH_URL_PREFIX + "/" +
ClassUtils.convertClassNameToResourcePath(clazz.getName()) + suffix };
}
/**
* Generate a modified version of the supplied locations array and returns it.
* <p>A plain path, e.g. "context.xml", will be treated as a
* classpath resource from the same package in which the specified class is
* defined. A path starting with a slash is treated as a fully qualified
* class path location, e.g.:
* "/org/springframework/whatever/foo.xml". A path which
* references a URL (e.g., a path prefixed with
* {@link ResourceUtils#CLASSPATH_URL_PREFIX classpath:},
* {@link ResourceUtils#FILE_URL_PREFIX file:}, <code>http:</code>,
* etc.) will be added to the results unchanged.
* <p>Subclasses can override this method to implement a different
* <em>location modification</em> strategy.
* @param clazz the class with which the locations are associated
* @param locations the resource locations to be modified
* @return an array of modified application context resource locations
*/
protected String[] modifyLocations(Class<?> clazz, String... locations) {
String[] modifiedLocations = new String[locations.length];
for (int i = 0; i < locations.length; i++) {
String path = locations[i];
if (path.startsWith("/")) {
modifiedLocations[i] = ResourceUtils.CLASSPATH_URL_PREFIX + path;
}
else if (!ResourcePatternUtils.isUrl(path)) {
modifiedLocations[i] = ResourceUtils.CLASSPATH_URL_PREFIX + "/"
+ StringUtils.cleanPath(ClassUtils.classPackageAsResourcePath(clazz) + "/" + path);
}
else {
modifiedLocations[i] = StringUtils.cleanPath(path);
}
}
return modifiedLocations;
}
/**
* Determine whether or not <em>default</em> resource locations should be
* generated if the <code>locations</code> provided to
* {@link #processLocations(Class,String...) processLocations()} are
* <code>null</code> or empty.
* <p>Can be overridden by subclasses to change the default behavior.
* @return always <code>true</code> by default
*/
protected boolean isGenerateDefaultLocations() {
return true;
}
/**
* Get the suffix to append to {@link ApplicationContext} resource
* locations when generating default locations.
* <p>Must be implemented by subclasses.
* @return the resource suffix; should not be <code>null</code> or empty
* @see #generateDefaultLocations(Class)
*/
protected abstract String getResourceSuffix();
}