org.springframework.core.type.filter.AssignableTypeFilter Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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
*
* https://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.core.type.filter;
import org.springframework.lang.Nullable;
import org.springframework.util.ClassUtils;
/**
* A simple filter which matches classes that are assignable to a given type.
*
* @author Rod Johnson
* @author Mark Fisher
* @author Ramnivas Laddad
* @since 2.5
*/
public class AssignableTypeFilter extends AbstractTypeHierarchyTraversingFilter {
private final Class targetType;
/**
* Create a new AssignableTypeFilter for the given type.
* @param targetType the type to match
*/
public AssignableTypeFilter(Class targetType) {
super(true, true);
this.targetType = targetType;
}
/**
* Return the {@code type} that this instance is using to filter candidates.
* @since 5.0
*/
public final Class getTargetType() {
return this.targetType;
}
@Override
protected boolean matchClassName(String className) {
return this.targetType.getName().equals(className);
}
@Override
@Nullable
protected Boolean matchSuperClass(String superClassName) {
return matchTargetType(superClassName);
}
@Override
@Nullable
protected Boolean matchInterface(String interfaceName) {
return matchTargetType(interfaceName);
}
@Nullable
protected Boolean matchTargetType(String typeName) {
if (this.targetType.getName().equals(typeName)) {
return true;
}
else if (Object.class.getName().equals(typeName)) {
return false;
}
else if (typeName.startsWith("java")) {
try {
Class clazz = ClassUtils.forName(typeName, getClass().getClassLoader());
return this.targetType.isAssignableFrom(clazz);
}
catch (Throwable ex) {
// Class not regularly loadable - can't determine a match that way.
}
}
return null;
}
}